[latexrefman-commits] [SCM] latexrefman updated: r679 - trunk

jimhefferon at gnu.org.ua jimhefferon at gnu.org.ua
Tue Jul 3 17:04:06 CEST 2018


Author: jimhefferon
Date: 2018-07-03 18:04:05 +0300 (Tue, 03 Jul 2018)
New Revision: 679

Modified:
   trunk/CTAN
   trunk/ChangeLog
   trunk/NEWS
   trunk/latex2e.dbk
   trunk/latex2e.dvi
   trunk/latex2e.html
   trunk/latex2e.info
   trunk/latex2e.pdf
   trunk/latex2e.texi
   trunk/latex2e.txt
   trunk/latex2e.xml
Log:
CTAN upload

Modified: trunk/CTAN
===================================================================
--- trunk/CTAN	2018-07-02 20:51:26 UTC (rev 678)
+++ trunk/CTAN	2018-07-03 15:04:05 UTC (rev 679)
@@ -14,11 +14,11 @@
 
 4) Check that the README is current.
 
-5) Commit the svn.
-
-6) Get the english and spanish stuff by running
+5) Get the english and spanish stuff by running
     make dist
 CTAN wants a .zip that is in a subdir, so this puts everything in the .zip
 inside latex2e-help-texinfo/ .
 
+6) Commit the svn.
+
 7) Upload.  It all goes to CTAN://info/latex2e-help-texinfo

Modified: trunk/ChangeLog
===================================================================
--- trunk/ChangeLog	2018-07-02 20:51:26 UTC (rev 678)
+++ trunk/ChangeLog	2018-07-03 15:04:05 UTC (rev 679)
@@ -1,3 +1,8 @@
+2018-07-03  Jim Hefferon  <jhefferon at smcvt.edu>
+
+	* latex2e.texi Do a CTAN release following the checklist in the
+	file CTAN.  Zip file contents from "make dist" looks OK to me.
+
 2018-07-02  Karl Berry  <karl at freefriends.org>
 
 	* latex2e.texi: typos, underfull boxes, mirror wording.

Modified: trunk/NEWS
===================================================================
--- trunk/NEWS	2018-07-02 20:51:26 UTC (rev 678)
+++ trunk/NEWS	2018-07-03 15:04:05 UTC (rev 679)
@@ -4,6 +4,25 @@
 Spanish translation originally from Nacho Pacheco (currently unmaintained).
 French translation originally from Vincent Belaiche.
 
+Changes in July 2018 release:
+
+We have gone through the two documents latex-info and
+latex2e-reference and checked that any information in those documents
+is in this one.
+
+There have also been other changes, including switching to a single
+unified index, a more uniform entry format, and many more examples and
+error messages.  There are a number of entirely new entries such as
+ones on \strut, caligraphic math fonts, \boldmath, and blackboard
+bold.  There have also been adjustments to the organization such as
+having separate sections for \part, \chapter, etc., and some
+combinations such as that of \clearpage and \cleardoublepage.
+
+In addition, there were many bug fixes, including greatly shrinking
+the size of one of the graphics.
+
+----------------------------------------------------------------
+
 Changes in April 2018 release:
 
 There is a new chapter on color and a new chapter on graphics
@@ -12,6 +31,7 @@
 diagram of the parameters, and a description of the tabbing
 environment.
 
+
 ----------------------------------------------------------------
 Changes in Aug 2017 release:
 

Modified: trunk/latex2e.dbk
===================================================================
--- trunk/latex2e.dbk	2018-07-02 20:51:26 UTC (rev 678)
+++ trunk/latex2e.dbk	2018-07-03 15:04:05 UTC (rev 679)
@@ -4,26 +4,35 @@
   <!ENTITY latex "LaTeX">
 ]>
 <book id="latex2e.dbk" lang="en">
+<!-- $Id$ -->
+<!-- Public domain. -->
         
 
-<title>&latex;2e unofficial reference manual (March 2018)</title>
+<title>&latex;2e unofficial reference manual (July 2018)</title>
 <!-- %**end of header (This is for running Texinfo on a region.) -->
 
 <!-- latex 2.09 commands should all be present now, -->
 <!-- xx but latex2e stuff is missing. -->
 <!-- xx random list of a few of the missing items is at the end of this file -->
 <!-- -->
-<!-- xx ending a run with errors -->
 <!-- xx ctan, distributions, components of TeX -->
 <!-- xx classes and packages - required, additional, useful; oberdiek; fonts -->
 <!-- -->
-<!-- xx merge http://ctan.org/pkg/latex-info (CTAN package latex-info) -->
-<!-- xx merge http://ctan.org/pkg/latex2e-reference -->
 <!-- xx merge permuted-index -->
 <!-- xx merge latex-manual from savannah -->
 <!-- xx merge display style math -->
-<!-- xx vertical mode, horizontal mode -->
-<!-- xx JH Discuss restricted execution -->
+<!-- xx JH explain nfss somewhere -->
+<!-- xx JH expand BiBTeX -->
+<!-- xx JH expand theorem, AMS math -->
+<!-- xx JH something on code listings -->
+<!-- xx JH ligatures -->
+<!-- xx JH \xspace -->
+<!-- xx JH \stretch -->
+<!-- xx JH \mathstrut -->
+<!-- xx JH \phantom https://tex.stackexchange.com/questions/4519/how-do-i-create-an-invisible-character -->
+<!-- xx JH \baselineskip https://texfaq.org/FAQ-baselinepar -->
+<!-- xx JH \contentsline, \@@dottedtocline? -->
+<!-- xx JH more on \write18, beyond what's mentioned in Command line. -->
 <!-- -->
 <!-- xx The typeset source2e has an index with all kernel -->
 <!-- xx commands, though some are internal and shouldn't be included. -->
@@ -31,7 +40,7 @@
 <!-- xx See also http://ctan.org/pkg/macros2e. -->
 
 <bookinfo><legalnotice><para>This document is an unofficial reference manual for &latex;, a
-document preparation system, version of March 2018.
+document preparation system, version of July 2018.
 </para>
 <para>This manual was originally translated from <filename>LATEX.HLP</filename> v1.0a in
 the VMS Help Library.  The pre-translation version was written by
@@ -67,10 +76,12 @@
 into another language, under the above conditions for modified versions.
 <!-- end of License -->
 </para></legalnotice></bookinfo>
+<!-- Merge into one index (arbitrarily chosen to be the concept index). -->
 
 
+
 <para>This document is an unofficial reference manual for &latex;, a
-document preparation system, version of March 2018.
+document preparation system, version of July 2018.
 </para>
 <para>This manual was originally translated from <filename>LATEX.HLP</filename> v1.0a in
 the VMS Help Library.  The pre-translation version was written by
@@ -115,7 +126,7 @@
 <title>&latex;2e: An unofficial reference manual</title>
 
 <para>This document is an unofficial reference manual (version of
-March 2018) for &latex;2e, a document preparation system.
+July 2018) for &latex;2e, a document preparation system.
 </para>
 
 
@@ -123,11 +134,11 @@
 <chapter label="1" id="About-this-document">
 <title>About this document</title>
 
-<indexterm role="fn"><primary><ulink url="http://puszcza.gnu.org.ua/software/latexrefman/">http://puszcza.gnu.org.ua/software/latexrefman/</ulink> home page</primary></indexterm>
+<indexterm role="cp"><primary>home page for manual</primary></indexterm>
 <para>This is an unofficial reference manual for the &latex;2e document
 preparation system, which is a macro package for the &tex;
 typesetting program (see <link linkend="Overview">Overview</link>).  This document’s home page is
-<ulink url="http://puszcza.gnu.org.ua/software/latexrefman/">http://puszcza.gnu.org.ua/software/latexrefman/</ulink>.  That page has links to the
+<ulink url="puszcza.gnu.org.ua/software/latexrefman">puszcza.gnu.org.ua/software/latexrefman</ulink>.  That page has links to the
 current output in various formats, sources, mailing list archives and
 subscriptions, and other infrastructure.
 </para>
@@ -223,17 +234,20 @@
 <indexterm role="cp"><primary>hello, world</primary></indexterm>
 
 <para>&latex; files have a simple global structure, with a standard beginning
-and ending.  Here is a “hello, world” example:
+and ending.  This is a small example.
 </para>
 <screen>\documentclass{article}
 \begin{document}
 Hello, \LaTeX\ world.
 \end{document}
 </screen>
+<para>Every &latex; document has a <literal>\begin{document}</literal> line and an
+<literal>\end{document}</literal> line.
+</para>
 <indexterm role="cp"><primary>document class, defined</primary></indexterm>
-<para>Here, the ‘<literal>article</literal>’ is the so-called <firstterm>document class</firstterm>,
-implemented in a file <filename>article.cls</filename>.  Any document class can be
-used.  A few document classes are defined by &latex; itself, and vast
+<para>Here, the ‘<literal>article</literal>’ is the <firstterm>document class</firstterm>.  It is implemented
+in a file <filename>article.cls</filename>.  You can use any document class on your
+system.  A few document classes are defined by &latex; itself, and vast
 array of others are widely available.  See <link linkend="Document-classes">Document classes</link>.
 </para>
 <indexterm role="cp"><primary>preamble, defined</primary></indexterm>
@@ -241,12 +255,13 @@
 <literal>\documentclass</literal> and the <literal>\begin{document}</literal> commands.
 This area is called the <firstterm>preamble</firstterm>.
 </para>
-<para>The <literal>\begin{document} ... \end{document}</literal> is a so-called
+<para>The <literal>\begin{document}</literal>, <literal>\end{document}</literal> pair defines an
 <indexterm role="cp"><primary>environment</primary></indexterm>
 <firstterm>environment</firstterm>; the ‘<literal>document</literal>’ environment (and no others) is
-required in all &latex; documents (see <link linkend="document">document</link>).  &latex;
-provides many environments itself, and many more are defined separately.
-See <link linkend="Environments">Environments</link>.
+required in all &latex; documents (see <link linkend="document">document</link>).  &latex; make
+available to you many environments that are documented here
+(see <link linkend="Environments">Environments</link>).  Many more are available to you from external
+packages, most importantly those available at CTAN (see <link linkend="CTAN">CTAN</link>).
 </para>
 <para>The following sections discuss how to produce PDF or other output from
 a &latex; input file.
@@ -256,7 +271,7 @@
 <sect1 label="2.2" id="Output-files">
 <title>Output files</title>
 
-<para>&latex; produces a main output file and at least two accessory files.
+<para>&latex; produces a main output file and at least two auxiliary files.
 The main output file’s name ends in either <filename>.dvi</filename> or <filename>.pdf</filename>.
 </para>
 <variablelist><varlistentry><term><literal>.dvi</literal>
@@ -266,7 +281,7 @@
 <indexterm role="fn"><primary>dvips command</primary></indexterm>
 <indexterm role="fn"><primary>dvipdfmx command</primary></indexterm>
 <indexterm role="fn"><primary>dvitype command</primary></indexterm>
-<para>If &latex; is invoked with the system command <command>latex</command> then it
+<anchor id="output-files-dvi"/><para>If &latex; is invoked with the system command <command>latex</command> then it
 produces a DeVice Independent file, with extension <filename>.dvi</filename>.  You
 can view this file with a command such as <command>xdvi</command>, or convert
 it to a PostScript <literal>.ps</literal> file with <command>dvips</command> or to a
@@ -279,7 +294,7 @@
 </term><listitem><indexterm role="fn"><primary>.pdf file</primary></indexterm>
 <indexterm role="cp"><primary>pdf&tex;</primary></indexterm>
 <indexterm role="fn"><primary>pdflatex command</primary></indexterm>
-<para>If &latex; is invoked via the system command <command>pdflatex</command>,
+<anchor id="output-files-pdf"/><para>If &latex; is invoked via the system command <command>pdflatex</command>,
 among other commands (see <link linkend="TeX-engines">&tex; engines</link>), then the main output is
 a Portable Document Format (PDF) file.  Typically this is a
 self-contained file, with all fonts and images included.
@@ -291,7 +306,7 @@
 </term><listitem><indexterm role="cp"><primary>transcript file</primary></indexterm>
 <indexterm role="cp"><primary>log file</primary></indexterm>
 <indexterm role="fn"><primary>.log file</primary></indexterm>
-<para>This transcript file contains summary information such as a list of
+<anchor id="output-files-log"/><para>This transcript file contains summary information such as a list of
 loaded packages.  It also includes diagnostic messages and perhaps
 additional information for any errors.
 </para>
@@ -301,7 +316,7 @@
 <indexterm role="cp"><primary>cross references, resolving</primary></indexterm>
 <indexterm role="cp"><primary>forward references, resolving</primary></indexterm>
 <indexterm role="cp"><primary>references, resolving forward</primary></indexterm>
-<para>Auxiliary information is used by &latex; for things such as
+<anchor id="output-files-aux"/><para>Auxiliary information is used by &latex; for things such as
 cross references.  For example, the first time that &latex; finds a
 forward reference—a cross reference to something that has not yet
 appeared in the source—it will appear in the output as a doubled
@@ -321,10 +336,11 @@
 <indexterm role="cp"><primary>table of contents file</primary></indexterm>
 <indexterm role="cp"><primary>contents file</primary></indexterm>
 <para>&latex; may produce yet more files, characterized by the filename
-ending.  These include a <literal>.lof</literal> file that is used to make a list
-of figures, a <literal>.lot</literal> file used to make a list of tables, and a
-<literal>.toc</literal> file used to make a table of contents.  A particular class
-may create others; the list is open-ended.
+ending.  These include a <literal>.lof</literal> file that is used to make a list of
+figures, a <literal>.lot</literal> file used to make a list of tables, and a
+<literal>.toc</literal> file used to make a table of contents (see <link linkend="Table-of-contents-etc_002e">Table of
+contents etc.</link>).  A particular class may create others; the list is
+open-ended.
 </para>
 
 </sect1>
@@ -340,14 +356,14 @@
 
 <para>&latex; is defined to be a set of commands that are run by a &tex;
 implementation (see <link linkend="Overview">Overview</link>).  This section gives a terse
-overview of the main programs.
+overview of the main programs (see also <link linkend="Command-line">Command line</link>).
 </para>
 <variablelist><varlistentry><term><literal>latex</literal>
 </term><term><literal>pdflatex</literal>
 </term><listitem><indexterm role="cp"><primary>pdf&tex; engine</primary></indexterm>
 <indexterm role="fn"><primary>etex command</primary></indexterm>
 <indexterm role="cp"><primary>e-&tex;</primary></indexterm>
-<para>In &tex; Live (<ulink url="http://tug.org/texlive">http://tug.org/texlive</ulink>), if &latex; is invoked
+<anchor id="tex-engines-latex"/><para>In &tex; Live (<ulink url="http://tug.org/texlive">http://tug.org/texlive</ulink>), if &latex; is invoked
 via either the system command <command>latex</command> or <command>pdflatex</command>,
 then the pdf&tex; engine is run (<ulink url="http://ctan.org/pkg/pdftex">http://ctan.org/pkg/pdftex</ulink>).
 When invoked as <command>latex</command>, the main output is a <filename>.dvi</filename>
@@ -367,7 +383,7 @@
 </listitem></varlistentry><varlistentry><term><literal>lualatex</literal>
 </term><listitem><indexterm role="fn"><primary>lualatex command</primary></indexterm>
 <indexterm role="cp"><primary>Lua&tex;</primary></indexterm>
-<para>If &latex; is invoked via the system command <command>lualatex</command>, the
+<anchor id="tex-engines-lualatex"/><para>If &latex; is invoked via the system command <command>lualatex</command>, the
 Lua&tex; engine is run (<ulink url="http://ctan.org/pkg/luatex">http://ctan.org/pkg/luatex</ulink>).  This
 program allows code written in the scripting language Lua
 (<ulink url="http://luatex.org">http://luatex.org</ulink>) to interact with &tex;’s typesetting.
@@ -381,7 +397,7 @@
 <indexterm role="cp"><primary>Xe&tex;</primary></indexterm>
 <indexterm role="fn"><primary>.xdv file</primary></indexterm>
 <indexterm role="fn"><primary>xdvipdfmx</primary></indexterm>
-<para>If &latex; is invoked with the system command <command>xelatex</command>, the
+<anchor id="tex-engines-xelatex"/><para>If &latex; is invoked with the system command <command>xelatex</command>, the
 Xe&tex; engine is run (<ulink url="http://tug.org/xetex">http://tug.org/xetex</ulink>).  Like Lua&tex;,
 Xe&tex; natively supports UTF-8 Unicode and TrueType and OpenType
 fonts, though the implementation is completely different, mainly using
@@ -458,7 +474,7 @@
   ...
 \end{verse}
 </screen>
-<para>See <link linkend="Environments">Environments</link> for a list of environments. 
+<para>See <link linkend="Environments">Environments</link> for a list of environments. 
 </para>
 <para>The <replaceable>environment name</replaceable> at the beginning must exactly match that at
 the end.  This includes the case where <replaceable>environment name</replaceable> ends in a
@@ -485,8 +501,8 @@
 </para>
 
 </sect2>
-<sect2 label="2.4.3" id="_005cmakeatletter-and-_005cmakeatother">
-<title><literal>\makeatletter</literal> and <literal>\makeatother</literal></title>
+<sect2 label="2.4.3" id="_005cmakeatletter-_0026-_005cmakeatother">
+<title><literal>\makeatletter</literal> & <literal>\makeatother</literal></title>
 
 <para>Synopsis:
 </para>
@@ -531,9 +547,9 @@
 in their names see <ulink url="http://ctan.org/pkg/macros2e">http://ctan.org/pkg/macros2e</ulink>. These macros are
 mainly intended to package or class authors.
 </para>
-<para>The example below is typical.  In the user’s class file is a command
-<literal>\thesis at universityname</literal>.  The user wants to change the
-definition.  These three lines should go in the preamble, before the
+<para>In this example the class file has a command
+<literal>\thesis at universityname</literal> that the user wants to change.  These
+three lines should go in the preamble, before the
 <literal>\begin{document}</literal>.
 </para>
 <screen>\makeatletter
@@ -552,8 +568,8 @@
 <para>Synopsis:
 </para>
 <screen>\newcommand{\mycmd}{\@ifstar{\mycmd at star}{\mycmd at nostar}}
-\newcommand{\mycmd at nostar}[<replaceable>non-starred command number of args</replaceable>]{<replaceable>body of non-starred command</replaceable>} 
-\newcommand{\mycmd at star}[<replaceable>starred command number of args</replaceable>]{<replaceable>body of starred command</replaceable>}
+\newcommand{\mycmd at nostar}[<replaceable>nostar-num-args</replaceable>]{<replaceable>nostar-body</replaceable>} 
+\newcommand{\mycmd at star}[<replaceable>star-num-args</replaceable>]{<replaceable>star-body</replaceable>}
 </screen>
 <para>Many standard &latex; environments or commands have a variant with the
 same name but ending with a star character <literal>*</literal>, an asterisk.
@@ -573,7 +589,7 @@
 same number of arguments or a different number, or no arguments at all.
 As always, in a &latex; document a command using at-sign <literal>@</literal>
 must be enclosed inside a <literal>\makeatletter ... \makeatother</literal> block
-(see <link linkend="_005cmakeatletter-and-_005cmakeatother">\makeatletter and \makeatother</link>).
+(see <link linkend="_005cmakeatletter-_0026-_005cmakeatother">\makeatletter & \makeatother</link>).
 </para>
 <para>This example of <literal>\@ifstar</literal> defines the command <literal>\ciel</literal> and a
 variant <literal>\ciel*</literal>.  Both have one required argument.  A call to
@@ -585,14 +601,15 @@
 \newcommand*{\ciel}{\@ifstar{\ciel at starred}{\ciel at unstarred}}
 </screen>
 <para>In the next example, the starred variant takes a different number of
-arguments than does the unstarred one.  With this definition, Agent
-007’s <literal>``My name is \agentsecret*{Bond},
-\agentsecret{James}{Bond}.''</literal> is equivalent to <literal>``My name is
-\textsc{Bond}, \textit{James} textsc{Bond}.''</literal>
+arguments than the unstarred one.  With this definition, Agent 007’s
+<literal>``My name is \agentsecret*{Bond},
+\agentsecret{James}{Bond}.''</literal> is equivalent to entering the commands
+<literal>``My name is \textsc{Bond}, \textit{James} textsc{Bond}.''</literal>
 </para>
 <screen>\newcommand*{\agentsecret at unstarred}[2]{\textit{#1} \textsc{#2}}
 \newcommand*{\agentsecret at starred}[1]{\textsc{#1}}
-\newcommand*{\agentsecret}{\@ifstar{\agentsecret at starred}{\agentsecret at unstarred}}
+\newcommand*{\agentsecret}{%
+  \@ifstar{\agentsecret at starred}{\agentsecret at unstarred}}
 </screen>
 <para>There are two sometimes more convenient ways to accomplish the work of
 <literal>\@ifstar</literal>.  The <filename>suffix</filename> package allows the construct
@@ -609,6 +626,39 @@
 </sect3>
 </sect2>
 </sect1>
+<sect1 label="2.5" id="CTAN">
+<title>CTAN: Comprehensive &tex; Archive Network</title>
+
+<indexterm role="cp"><primary>CTAN</primary></indexterm>
+
+<para>The Comprehensive &tex; Archive Network, CTAN, is the &tex; and
+&latex; community’s repository of free material.  It is a set of
+Internet sites around the world that offer material related to &latex;
+for download.  Visit CTAN on the web at <ulink url="https://ctan.org">https://ctan.org</ulink>.
+</para>
+<para>This material is organized into packages, discrete bundles that
+typically offer some coherent functionality and are maintained by one
+person or a small number of people.  For instance, many publishers have
+a package that allows authors to format papers to that publisher’s
+specifications.
+</para>
+<para>In addition to the massive holdings, the web site offers features such
+as search by name or by functionality.
+</para>
+<indexterm role="cp"><primary>DANTE e.V.</primary></indexterm>
+<indexterm role="cp"><primary>mirrors of CTAN</primary></indexterm>
+<para>CTAN is not a single site, but instead is a set of sites. One of the
+sites is the core. This site actively manages the material, for
+instance, by accepting uploads of new or updated packages. It is
+hosted by the German &tex; group DANTE e.V. Other sites around the
+world help out by mirroring, that is, automatically syncing their
+collections with the core site and then in turn making their copies
+publicly available. This gives users close to their location better
+access and relieves the load on the core site. The list of mirrors is
+at <ulink url="https://ctan.org/mirrors">https://ctan.org/mirrors</ulink>.
+</para>
+
+</sect1>
 </chapter>
 <chapter label="3" id="Document-classes">
 <title>Document classes</title>
@@ -632,23 +682,23 @@
 see <link linkend="Overview">Overview</link>.)
 </para>
 <variablelist><varlistentry><term><literal>article</literal>
-</term><listitem><para>For a journal article, a presentation, and miscellaneous general use.
+</term><listitem><anchor id="document-classes-article"/><para>For a journal article, a presentation, and miscellaneous general use.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>book</literal>
-</term><listitem><para>Full-length books, including chapters and possibly including front
+</term><listitem><anchor id="document-classes-book"/><para>Full-length books, including chapters and possibly including front
 matter, such as a preface, and back matter, such as an appendix
 (see <link linkend="Front_002fback-matter">Front/back matter</link>).
 </para>
 </listitem></varlistentry><varlistentry><term><literal>letter</literal>
-</term><listitem><para>Mail, optionally including mailing labels 
+</term><listitem><anchor id="document-classes-letter"/><para>Mail, optionally including mailing labels 
 (see <link linkend="Letters">Letters</link>).
 </para>
 </listitem></varlistentry><varlistentry><term><literal>report</literal>
-</term><listitem><para>For documents of length between an <literal>article</literal> and a <literal>book</literal>,
+</term><listitem><anchor id="document-classes-report"/><para>For documents of length between an <literal>article</literal> and a <literal>book</literal>,
 such as technical reports or theses, which may contain several chapters.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>slides</literal>
-</term><listitem><para>For slide presentations—rarely used today.  In its place the
+</term><listitem><anchor id="document-classes-slides"/><para>For slide presentations—rarely used today.  In its place the
 <literal>beamer</literal> package is perhaps the most prevalent (see <link linkend="beamer-template">beamer
 template</link>).
 </para>
@@ -665,9 +715,9 @@
 <indexterm role="cp"><primary>class options</primary></indexterm>
 <indexterm role="cp"><primary>global options</primary></indexterm>
 
-<para>You can specify so-called <firstterm>global options</firstterm> or <firstterm>class options</firstterm> to
-the <literal>\documentclass</literal> command by enclosing them in square brackets.
-To specify more than one <replaceable>option</replaceable>, separate them with a comma, as in:
+<para>You can specify <firstterm>global options</firstterm> or <firstterm>class options</firstterm> to the
+<literal>\documentclass</literal> command by enclosing them in square brackets.  To
+specify more than one <replaceable>option</replaceable>, separate them with a comma.
 </para>
 <screen>\documentclass[<replaceable>option1</replaceable>,<replaceable>option2</replaceable>,...]{<replaceable>class</replaceable>}
 </screen>
@@ -854,7 +904,7 @@
 <para>Inside of a class or package file you can use the at-sign <literal>@</literal> as a
 character in command names without having to surround the code
 containing that command with <literal>\makeatletter</literal> and
-<literal>\makeatother</literal>.  See <link linkend="_005cmakeatletter-and-_005cmakeatother">\makeatletter and \makeatother</link>. This allow
+<literal>\makeatother</literal>.  See <link linkend="_005cmakeatletter-_0026-_005cmakeatother">\makeatletter & \makeatother</link>. This allow
 you to create commands that users will not accidentally redefine.
 Another technique is to preface class- or package-specific commands with
 some string to prevent your class or package from interfering with
@@ -897,7 +947,6 @@
 most of its work: declaring new variables, commands and fonts, and
 loading other files.
 </para></listitem></orderedlist>
-
 <para>Here is a starting class file, which should be saved as <filename>stub.cls</filename>
 where &latex; can find it, for example in the same directory as the
 <filename>.tex</filename> file.
@@ -919,6 +968,7 @@
 of the descriptions here derive from this document), or the tutorial
 <ulink url="https://www.tug.org/TUGboat/tb26-3/tb84heff.pdf">https://www.tug.org/TUGboat/tb26-3/tb84heff.pdf</ulink>.
 </para>
+
 </sect2>
 <sect2 label="3.3.2" id="Class-and-package-commands">
 <title>Class and package commands</title>
@@ -1010,10 +1060,10 @@
 <indexterm role="cp"><primary>package options</primary></indexterm>
 <indexterm role="cp"><primary>options, class</primary></indexterm>
 <indexterm role="cp"><primary>options, package</primary></indexterm>
-<para>Make an option available to a user, for invoking in their
+<para>Make an option available to a user to invoke in their
 <literal>\documentclass</literal> command.  For example, the <literal>smcmemo</literal> class
-could have an option allowing users to put the institutional logo on the
-first page with <literal>\documentclass[logo]{smcmemo}</literal>.  The class file
+could have an option <literal>\documentclass[logo]{smcmemo}</literal> allowing
+users to put the institutional logo on the first page.  The class file
 must contain <literal>\DeclareOption{logo}{<replaceable>code</replaceable>}</literal> (and later,
 <literal>\ProcessOptions</literal>).
 </para>
@@ -1058,14 +1108,14 @@
 </para>
 <indexterm role="cp"><primary>package, <literal>etoolbox</literal></primary></indexterm>
 <indexterm role="cp"><primary><literal>etoolbox</literal> package</primary></indexterm>
- 
-<para>The <literal>etoolbox</literal> package offers commands <literal>\newrobustcmd</literal>,
-<literal>\newrobustcmd*</literal>, <literal>\renewrobustcmd</literal>, <literal>\renewrobustcmd*</literal>,
-<literal>\providerobustcmd</literal>, and <literal>\providerobustcmd*</literal> which are similar
-to <literal>\newcommand</literal>, <literal>\newcommand*</literal>, <literal>\renewcommand</literal>,
-<literal>\renewcommand*</literal>, <literal>\providecommand</literal>, and
-<literal>\providecommand*</literal>, but define a robust <replaceable>cmd</replaceable> with two advantages
-as compared to <literal>\DeclareRobustCommand</literal>:
+<para>The <filename>etoolbox</filename> package offers the commands
+<literal>\newrobustcmd</literal>, <literal>\newrobustcmd*</literal>, as well as the commands
+<literal>\renewrobustcmd</literal>, <literal>\renewrobustcmd*</literal>, and the commands
+<literal>\providerobustcmd</literal>, and <literal>\providerobustcmd*</literal>.  These are
+similar to <literal>\newcommand</literal>, <literal>\newcommand*</literal>,
+<literal>\renewcommand</literal>, <literal>\renewcommand*</literal>, <literal>\providecommand</literal>, and
+<literal>\providecommand*</literal>, but define a robust <replaceable>cmd</replaceable> with two
+advantages as compared to <literal>\DeclareRobustCommand</literal>:
 </para><orderedlist numeration="arabic"><listitem><para>They use the low-level e-&tex; protection mechanism rather than the
 higher level &latex; <literal>\protect</literal> mechanism, so they do not incur
 the slight loss of performance mentioned above, and
@@ -1080,13 +1130,16 @@
 </term></varlistentry><varlistentry><term><literal>\InputIfFileExists{<replaceable>file name</replaceable>}{<replaceable>true code</replaceable>}{<replaceable>false code</replaceable>}</literal>
 </term><listitem><indexterm role="fn"><primary>\IfFileExists</primary></indexterm>
 <indexterm role="fn"><primary>\InputIfFileExists</primary></indexterm>
-<para>Execute <replaceable>true code</replaceable> if &latex; can find the file <filename><replaceable>file
-name</replaceable></filename> and <replaceable>false code</replaceable> otherwise.  In the second case it inputs the
-file immediately after executing <replaceable>true code</replaceable>.  Thus
-<literal>\IfFileExists{img.pdf}{\includegraphics{img.pdf}}{\typeout{WARNING:
-img.pdf not found}}</literal> will include the graphic <filename>img.pdf</filename> if it is
-found but otherwise just give a warning.
+<para>Execute <replaceable>true code</replaceable> if &latex; finds the file <filename><replaceable>file
+name</replaceable></filename> or <replaceable>false code</replaceable> otherwise.  In the first case it executing
+<replaceable>true code</replaceable> and then inputs the file.  Thus the command
 </para>
+<screen>\IfFileExists{img.pdf}{%
+  \includegraphics{img.pdf}}{\typeout{!! img.pdf not found}
+</screen>
+<para>will include the graphic <filename>img.pdf</filename> if it is found and otherwise
+give a warning.
+</para>
 <para>This command looks for the file in all search paths that &latex; uses,
 not only in the current directory.  To look only in the current
 directory do something like <literal>\IfFileExists{./filename}{<replaceable>true
@@ -1110,12 +1163,14 @@
 <!-- and do some actions conditionnally on version later or not to some -->
 <!-- date. -->
 </para>
-<para>If you request a <replaceable>release date</replaceable> and the date of
-the package installed on your system is earlier, then you get a warning
-on the screen and in the log like <literal>You have requested, on input
-line 4, version `2038/01/19' of document class article, but only version
-`2014/09/29 v1.4h Standard LaTeX document class' is available.</literal>
+<para>If you request a <replaceable>release date</replaceable> and the date of the package
+installed on your system is earlier, then you get a warning on the
+screen and in the log like this.
 </para>
+<screen>You have requested, on input line 4, version `2038/01/19' of
+document class article, but only version `2014/09/29 v1.4h
+Standard LaTeX document class' is available.
+</screen>
 <para>The command version <literal>\LoadClassWithOptions</literal> uses the list of
 options for the current class.  This means it ignores any options passed
 to it via <literal>\PassOptionsToClass</literal>.  This is a convenience command
@@ -1147,10 +1202,11 @@
 features, include the optional <replaceable>format date</replaceable> on which those features
 were implemented.  If present it must be in the form <literal>YYYY/MM/DD</literal>.
 If the format version installed on your system is earlier than
-<replaceable>format date</replaceable> then you get a warning like ‘<literal>You have requested
-release `2038/01/20' of LaTeX, but only release `2016/02/01' is
-available.</literal>’
+<replaceable>format date</replaceable> then you get a warning like this.
 </para>
+<screen>You have requested release `2038/01/20' of LaTeX, but only
+release `2016/02/01' is available.
+</screen>
 </listitem></varlistentry><varlistentry><term><literal>\OptionNotUsed</literal>
 </term><listitem><indexterm role="fn"><primary>\OptionNotUsed</primary></indexterm>
 <para>Adds the current option to the list of unused options.  Can only be used
@@ -1180,18 +1236,21 @@
 </para>
 <para>If your own code is bringing in a package twice then you can collapse
 that to once, for example replacing the two
-<literal>\RequirePackage[landscape]{geometry}\RequirePackage[margins=1in]{geometry}</literal>
-with the single
-<literal>\RequirePackage[landscape,margins=1in]{geometry}</literal>.  But if you
-are loading a package that in turn loads another package then you need
-to queue up the options you desire for this other package.  For
-instance, suppose the package <literal>foo</literal> loads the package
-<literal>geometry</literal>.  Instead of
-<literal>\RequirePackage{foo}\RequirePackage[draft]{graphics}</literal> you must
-write <literal>\PassOptionsToPackage{draft}{graphics}
-\RequirePackage{foo}</literal>.  (If <literal>foo.sty</literal> loads an option in conflict
-with what you want then you may have to look into altering its source.)
+<literal>\RequirePackage[landscape]{geometry}</literal> and
+<literal>\RequirePackage[margins=1in]{geometry}</literal> with the single command
+<literal>\RequirePackage[landscape,margins=1in]{geometry}</literal>.
 </para>
+<para>However, imagine that you are loading <filename>firstpkg</filename> and inside that
+package it loads <filename>secondpkg</filename>, and you need the second package to be
+loaded with option <literal>draft</literal>.  Then before doing the first package
+you must queue up the options for the second package, like this.
+</para>
+<screen>\PassOptionsToPackage{draft}{secondpkg}
+\RequirePackage{firstpkg}
+</screen>
+<para>(If <literal>firstpkg.sty</literal> loads an option in conflict with what you want
+then you may have to alter its source.)
+</para>
 <para>These commands are useful for general users as well as class and package
 writers.  For instance, suppose a user wants to load the <literal>graphicx</literal>
 package with the option <literal>draft</literal> and also wants to use a class
@@ -1238,41 +1297,42 @@
 the order of declaration in the class or package. For a package this
 means that the global options are processed first.
 </para>
-
 </listitem></varlistentry><varlistentry><term><literal>\ProvidesClass{<replaceable>class name</replaceable>}[<replaceable>release date</replaceable> <replaceable>brief additional information</replaceable>]</literal>
 </term></varlistentry><varlistentry><term><literal>\ProvidesClass{<replaceable>class name</replaceable>}[<replaceable>release date</replaceable>]</literal>
 </term></varlistentry><varlistentry><term><literal>\ProvidesPackage{<replaceable>package name</replaceable>}[<replaceable>release date</replaceable> <replaceable>brief additional information</replaceable>]</literal>
 </term></varlistentry><varlistentry><term><literal>\ProvidesPackage{<replaceable>package name</replaceable>}[<replaceable>release date</replaceable>]</literal>
 </term><listitem><indexterm role="fn"><primary>\ProvidesClass</primary></indexterm>
 <indexterm role="fn"><primary>\ProvidesPackage</primary></indexterm>
-<para>Identifies the class or package, printing a message to the screen and the log file.
+<para>Identifies the class or package, printing a message to the screen and
+the log file.
 </para>
-<para>When a user writes <literal>\documentclass{smcmemo}</literal> then &latex; loads
-the file <filename>smcmemo.cls</filename>.  Similarly, a user writing
-<literal>\usepackage{test}</literal> prompts &latex; to load the file
-<literal>test.sty</literal>.  If the name of the file does not match the declared
-class or package name then you get a warning.  Thus, if you invoke
+<para>When you load a class or package, for example with
+<literal>\documentclass{smcmemo}</literal> or <literal>\usepackage{test}</literal>, &latex;
+inputs a file.  If the name of the file does not match the class or
+package name declared in it then you get a warning.  Thus, if you invoke
 <literal>\documentclass{smcmemo}</literal>, and the file <filename>smcmemo.cls</filename> has
 the statement <literal>\ProvidesClass{xxx}</literal> then you get a warning like
 <literal>You have requested document class `smcmemo', but the document
 class provides 'xxx'.</literal>  This warning does not prevent &latex; from
 processing the rest of the class file normally.
 </para>
-<para>If you include the optional argument, then you must include the date, before
-the first space if any, and it must have the form <literal>YYYY/MM/DD</literal>. The rest
-of the optional argument is free-form, although it traditionally identifies
-the class, and is written to the screen during compilation and to the
-log file.  Thus, if your file <filename>smcmemo.cls</filename> contains the line
-<literal>\ProvidesClass{smcmemo}[2008/06/01 v1.0 SMC memo class]</literal> and your
-document’s first line is <literal>\documentclass{smcmemo}</literal> then you will
-see <literal>Document Class: smcmemo 2008/06/01 v1.0 SMC memo class</literal>.
+<para>If you include the optional argument then you must include a date,
+before any spaces, of the form <literal>YYYY/MM/DD</literal>. The rest of the
+optional argument is free-form, although it traditionally identifies the
+class, and is written to the screen during compilation and to the log
+file.  Thus, if your file <filename>smcmemo.cls</filename> contains the line
+<literal>\ProvidesClass{smcmemo}[2008/06/01 v1.0 SMC memo class]</literal> and
+your document’s first line is <literal>\documentclass{smcmemo}</literal> then you
+will see <literal>Document Class: smcmemo 2008/06/01 v1.0 SMC memo class</literal>.
 </para>
 <para>The date in the optional argument allows class and package users to ask
-to be warned if the version of the class or package installed on their
-system is earlier than <replaceable>release date</replaceable>, by using the optional arguments
-such as <literal>\documentclass{smcmemo}[2018/10/12]</literal> or
-<literal>\usepackage{foo}[[2017/07/07]]</literal>.  (Note that package users only
-rarely include a date, and class users almost never do.)
+to be warned if the version of the class or package is earlier than
+<replaceable>release date</replaceable>.  For instance, a user could enter
+<literal>\documentclass{smcmemo}[2018/10/12]</literal> or
+<literal>\usepackage{foo}[[2017/07/07]]</literal> to require a class or package
+with certain features by specifying that it must be released no earlier
+than the given date.  (Although, in practice package users only rarely
+include a date, and class users almost never do.)
 </para>
 </listitem></varlistentry><varlistentry><term><literal>\ProvidesFile{<replaceable>file name</replaceable>}[<replaceable>additional information</replaceable>]</literal>
 </term><listitem><indexterm role="fn"><primary>\ProvidesFile</primary></indexterm>
@@ -1287,11 +1347,11 @@
 </term></varlistentry><varlistentry><term><literal>\RequirePackageWithOptions{<replaceable>package name</replaceable>}[<replaceable>release date</replaceable>]</literal>
 </term><listitem><indexterm role="fn"><primary>\RequirePackage</primary></indexterm>
 <indexterm role="fn"><primary>\RequirePackageWithOptions</primary></indexterm>
-<para>Load a package, like the document author command <literal>\usepackage</literal>.
-See <link linkend="Additional-packages">Additional packages</link>. An example is
-<literal>\RequirePackage[landscape,margin=1in]{geometry}</literal>.  Note that the
-&latex; development team strongly recommends use of these commands over
-Plain &tex;’s <literal>\input</literal>; see the Class Guide.
+<para>Load a package, like the command <literal>\usepackage</literal> (see <link linkend="Additional-packages">Additional
+packages</link>). The &latex; development team strongly recommends use of
+these commands over Plain &tex;’s <literal>\input</literal>; see the Class
+Guide.  An example is
+<literal>\RequirePackage[landscape,margin=1in]{geometry}</literal>.
 </para>
 <para>The <replaceable>option list</replaceable>, if present, is a comma-separated list.  The
 <replaceable>release date</replaceable>, if present, must have the form <replaceable>YYYY/MM/DD</replaceable>.  If
@@ -1338,30 +1398,28 @@
 
 <para>The following type style commands are supported by &latex;.
 </para>
-<para>This first group of commands is typically used with an argument, as in
-<literal>\textit{<replaceable>text</replaceable>}</literal>.  In the table below, the corresponding
-command in parenthesis is the “declaration form”, which takes no
-arguments, as in <literal>{\itshape <replaceable>text</replaceable>}</literal>.  The scope of the
-declaration form lasts until the next type style command or the end of
-the current group.
+<para>In the table below the listed commands, the <literal>\text...</literal>  commands,
+is used with an argument, as in <literal>\textit{<replaceable>text</replaceable>}</literal>.  This is
+the preferred form.  But shown after it, in parenthesis, is the
+corresponding declaration form, which is sometimes useful.  This form
+takes no arguments, as in <literal>{\itshape <replaceable>text</replaceable>}</literal>.  The scope of
+the declaration form lasts until the next type style command or the end
+of the current group.  In addition, each has an environment form such as
+<literal>\begin{itshape}...\end{itshape}</literal>.
 </para>
-<para>These commands, in both the argument form and the declaration form,
-are cumulative; e.g., you can say either <literal>\sffamily\bfseries</literal> or
-<literal>\bfseries\sffamily</literal> to get bold sans serif.
+<para>These commands, in both the argument form and the declaration form, are
+cumulative; for instance you can get bold sans serif by saying either of
+<literal>\sffamily\bfseries</literal> or <literal>\bfseries\sffamily</literal>.
 </para>
-<para>You can alternatively use an environment form of the declarations; for
-instance, <literal>\begin{ttfamily}...\end{ttfamily}</literal>.
-</para>
 <indexterm role="fn"><primary>\nocorrlist</primary></indexterm>
 <indexterm role="fn"><primary>\nocorr</primary></indexterm>
-<para>These font-switching commands automatically insert italic corrections
-if needed.  (See <link linkend="_005c_002f">\/</link>, for the details of italic corrections.)
-Specifically, they insert the italic correction unless the following
-character is in the list <literal>\nocorrlist</literal>, which by default consists
-of a period and a comma.  To suppress the automatic insertion of
-italic correction, use <literal>\nocorr</literal> at the start or end of the
-command argument, such as <literal>\textit{\nocorr text}</literal> or
-<literal>\textsc{text \nocorr}</literal>.
+<para>One advantage of these commands is that they automatically insert italic
+corrections if needed (see <link linkend="_005c_002f">\/</link>).  Specifically, they insert the
+italic correction unless the following character is in the list
+<literal>\nocorrlist</literal>, which by default consists of a period and a comma.
+To suppress the automatic insertion of italic correction, use
+<literal>\nocorr</literal> at the start or end of the command argument, such as
+<literal>\textit{\nocorr text}</literal> or <literal>\textsc{text \nocorr}</literal>.
 </para>
 <variablelist><varlistentry><term><literal>\textrm (\rmfamily)</literal>
 </term><listitem><indexterm role="fn"><primary>\textrm</primary></indexterm>
@@ -1424,11 +1482,15 @@
 will be in roman.
 </para>
 <para>&latex; also provides the following commands, which unconditionally
-switch to the given style, that is, are <emphasis>not</emphasis> cumulative.  Also,
-they are used differently than the above commands:
-<literal>{\<replaceable>cmd</replaceable>...}</literal> instead of <literal>\<replaceable>cmd</replaceable>{...}</literal>.  These
-are two unrelated constructs.
+switch to the given style, that is, are <emphasis>not</emphasis> cumulative.  They are
+used as declarations: <literal>{\<replaceable>cmd</replaceable>...}</literal> instead of
+<literal>\<replaceable>cmd</replaceable>{...}</literal>.
 </para>
+<para>(The unconditional commands below are an older version of font
+switching. The earlier commands are an improvement in most
+circumstances. But sometimes an unconditional font switch is precisely
+what you want.)
+</para>
 <variablelist><varlistentry><term><indexterm role="fn"><primary>\bf</primary></indexterm><literal>\bf</literal>
 </term><listitem><indexterm role="cp"><primary>bold font</primary></indexterm>
 <para>Switch to bold face.
@@ -1468,13 +1530,6 @@
 </listitem></varlistentry></variablelist>
 <para>The <literal>\em</literal> command is the unconditional version of <literal>\emph</literal>.
 </para>
-<para>(Some people consider the unconditional font-switching commands, such
-as <literal>\tt</literal>, obsolete and that only the cumulative commands
-(<literal>\texttt</literal>) should be used.  Others think that both sets of
-commands have their place and sometimes an unconditional font switch
-is precisely what you want; for one example,
-see <link linkend="description"><literal>description</literal></link>.)
-</para>
 <para>The following commands are for use in math mode.  They are not
 cumulative, so <literal>\mathbf{\mathit{<replaceable>symbol</replaceable>}}</literal> does not
 create a boldface and italic <replaceable>symbol</replaceable>; instead, it will just be in
@@ -1561,7 +1616,7 @@
 <indexterm role="fn"><primary>\huge</primary></indexterm>
 <indexterm role="fn"><primary>\Huge</primary></indexterm>
 
-<informaltable><tgroup cols="4"><colspec colwidth="21*"></colspec><colspec colwidth="5*"></colspec><colspec colwidth="5*"></colspec><colspec colwidth="5*"></colspec><thead><row><entry><para>Command  </para></entry><entry><para><literal>10pt</literal>  </para></entry><entry><para><literal>11pt</literal>  </para></entry><entry><para><literal>12pt</literal>
+<informaltable><tgroup cols="4"><colspec colwidth="23*"></colspec><colspec colwidth="7*"></colspec><colspec colwidth="7*"></colspec><colspec colwidth="5*"></colspec><thead><row><entry><para>Command  </para></entry><entry><para><literal>10pt</literal>  </para></entry><entry><para><literal>11pt</literal>  </para></entry><entry><para><literal>12pt</literal>
 </para></entry></row></thead><tbody><row><entry><para><literal>\tiny</literal>
 </para></entry><entry><para>5          </para></entry><entry><para>6          </para></entry><entry><para>6
 </para></entry></row><row><entry><para><literal>\scriptsize</literal>
@@ -1583,11 +1638,20 @@
 </para></entry></row><row><entry><para><literal>\Huge</literal>
 </para></entry><entry><para>24.88      </para></entry><entry><para>24.88      </para></entry><entry><para>24.88
 </para></entry></row></tbody></tgroup></informaltable>
-<para>The commands as listed here are “declaration forms”. The scope of
-the declaration form lasts until the next type style command or the
-end of the current group.  You can also use the environment form of
-these commands; for instance, <literal>\begin{tiny}...\end{tiny}</literal>.
+<para>The commands are listed here in declaration forms. You use them by
+declaring them, as with this example.
 </para>
+<screen>\begin{quotation} \small
+  The Tao that can be named is not the eternal Tao.
+\end{quotation}
+</screen>
+<para>The scope of the <literal>\small</literal> lasts until the end of the
+<literal>quotation</literal> environment.  It would also end at the next type style
+command or the end of the current group, so you could enclose it in
+extra curly braces <literal>{\small We are here, we are here, we are
+here!}</literal>.  You can instead use the environment form of these commands;
+for instance, <literal>\begin{tiny}...\end{tiny}</literal>.
+</para>
 
 </sect1>
 <sect1 label="4.3" id="Low_002dlevel-font-commands">
@@ -1602,7 +1666,7 @@
 <!-- xx but it should be complete -->
 <!-- xx something about ultimately reading ENCFAM.fd? -->
 </para>
-<variablelist><varlistentry><term><literal>\fontencoding{<replaceable>encoding</replaceable>}</literal>
+<variablelist><anchor id="low-level-font-commands-fontencoding"/><varlistentry><term><literal>\fontencoding{<replaceable>encoding</replaceable>}</literal>
 </term><listitem><indexterm role="fn"><primary>\fontencoding</primary></indexterm>
 <para>Select the font encoding, the encoding of the output font. There are a
 large number of valid encodings.  The most common are <literal>OT1</literal>,
@@ -1613,16 +1677,16 @@
 hyphenate words containing accented letters. For more, see
 <ulink url="https://ctan.org/pkg/encguide">https://ctan.org/pkg/encguide</ulink>.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>\fontfamily{<replaceable>family</replaceable>}</literal>
+<anchor id="low-level-font-commands-fontfamily"/></listitem></varlistentry><varlistentry><term><literal>\fontfamily{<replaceable>family</replaceable>}</literal>
 </term><listitem><indexterm role="fn"><primary>\fontfamily</primary></indexterm>
 <indexterm role="cp"><primary>families, of fonts</primary></indexterm>
 <indexterm role="cp"><primary>font catalogue</primary></indexterm>
 <para>Select the font family.  The web page
 <ulink url="http://www.tug.dk/FontCatalogue/">http://www.tug.dk/FontCatalogue/</ulink> provides one way to browse
 through many of the fonts easily used with &latex;.  Here are
-examples of some common families:
+examples of some common families.
 </para>
-<informaltable><tgroup cols="2"><colspec colwidth="4*"></colspec><colspec colwidth="31*"></colspec><tbody><row><entry><para><literal>pag</literal>
+<informaltable><tgroup cols="2"><colspec colwidth="4*"></colspec><colspec colwidth="37*"></colspec><tbody><row><entry><para><literal>pag</literal>
 </para></entry><entry><para>Avant Garde
 </para></entry></row><row><entry><para><literal>fvs</literal>
 </para></entry><entry><para>Bitstream Vera Sans
@@ -1664,7 +1728,7 @@
 </para></entry><entry><para>Zapf Chancery
 </para></entry></row></tbody></tgroup></informaltable>
 
-</listitem></varlistentry><varlistentry><term><literal>\fontseries{<replaceable>series</replaceable>}</literal>
+<anchor id="low-level-font-commands-fontseries"/></listitem></varlistentry><varlistentry><term><literal>\fontseries{<replaceable>series</replaceable>}</literal>
 </term><listitem><indexterm role="fn"><primary>\fontseries</primary></indexterm>
 <indexterm role="cp"><primary>series, of fonts</primary></indexterm>
 <para>Select the font series.  A <firstterm>series</firstterm> combines a <firstterm>weight</firstterm> and a
@@ -1708,7 +1772,6 @@
 <para>The possible values for width, individually, are (the meaning and
 relationship of these terms varies with individual typefaces):
 </para>
-
 <informaltable><tgroup cols="2"><colspec colwidth="2*"></colspec><colspec colwidth="15*"></colspec><tbody><row><entry><para><literal>uc</literal>
 </para></entry><entry><para>Ultra condensed
 </para></entry></row><row><entry><para><literal>ec</literal>
@@ -1728,7 +1791,6 @@
 </para></entry></row><row><entry><para><literal>ux</literal>
 </para></entry><entry><para>Ultra expanded
 </para></entry></row></tbody></tgroup></informaltable>
-
 <para>When forming the <replaceable>series</replaceable> string from the weight and width, drop the
 <literal>m</literal> that stands for medium weight or medium width, unless both
 weight and width are <literal>m</literal>, in which case use just one
@@ -1737,7 +1799,7 @@
 </listitem></varlistentry><varlistentry><term><literal>\fontshape{<replaceable>shape</replaceable>}</literal>
 </term><listitem><indexterm role="fn"><primary>\fontshape</primary></indexterm>
 <indexterm role="cp"><primary>shapes, of fonts</primary></indexterm>
-<para>Select font shape. Valid shapes are:
+<anchor id="low-level-font-commands-fontshape"/><para>Select font shape. Valid shapes are:
 </para>
 <informaltable><tgroup cols="2"><colspec colwidth="2*"></colspec><colspec colwidth="19*"></colspec><tbody><row><entry><para><literal>n</literal>
 </para></entry><entry><para>Upright (normal)
@@ -1752,11 +1814,10 @@
 </para></entry></row><row><entry><para><literal>ol</literal>
 </para></entry><entry><para>Outline
 </para></entry></row></tbody></tgroup></informaltable>
-
 <para>The two last shapes are not available for most font families, and
 small caps are often missing as well.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>\fontsize{<replaceable>size</replaceable>}{<replaceable>skip</replaceable>}</literal>
+<anchor id="low-level-font-commands-fontsize"/></listitem></varlistentry><varlistentry><term><literal>\fontsize{<replaceable>size</replaceable>}{<replaceable>skip</replaceable>}</literal>
 </term><listitem><indexterm role="fn"><primary>\fontsize</primary></indexterm>
 <indexterm role="cp"><primary>font size</primary></indexterm>
 <indexterm role="fn"><primary>\baselineskip</primary></indexterm>
@@ -1768,7 +1829,7 @@
 Changing <literal>\baselineskip</literal> directly is inadvisable since its value is
 reset every time a size change happens; see <literal>\baselinestretch</literal>, next.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>\baselinestretch</literal>
+<anchor id="low-level-font-commands-baselinestretch"/></listitem></varlistentry><varlistentry><term><literal>\baselinestretch</literal>
 </term><listitem><indexterm role="fn"><primary>\baselinestretch</primary></indexterm>
 <para>&latex; multiplies the line spacing by the value of the
 <literal>\baselinestretch</literal> parameter; the default factor is 1.  A change
@@ -1787,7 +1848,7 @@
 where that is typically desirable, such as footnotes and figure
 captions.  See the package documentation.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>\linespread{<replaceable>factor</replaceable>}</literal>
+<anchor id="low-level-font-commands-linespread"/></listitem></varlistentry><varlistentry><term><literal>\linespread{<replaceable>factor</replaceable>}</literal>
 </term><listitem><indexterm role="fn"><primary>\linespread</primary></indexterm>
 <para>Equivalent to
 <literal>\renewcommand{\baselinestretch}{<replaceable>factor</replaceable>}</literal>, and
@@ -1795,7 +1856,7 @@
 Best specified in the preamble, or use the <literal>setspace</literal> package, as
 just described.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>\selectfont</literal>
+<anchor id="low-level-font-commands-selectfont"/></listitem></varlistentry><varlistentry><term><literal>\selectfont</literal>
 </term><listitem><indexterm role="fn"><primary>\selectfont</primary></indexterm>
 <para>The effects of the font commands described above do not happen until
 <literal>\selectfont</literal> is called, as in
@@ -1806,7 +1867,7 @@
 
 (see <link linkend="_005cnewcommand-_0026-_005crenewcommand">\newcommand & \renewcommand</link>).
 </para>
-</listitem></varlistentry><varlistentry><term><literal>\usefont{<replaceable>enc</replaceable>}{<replaceable>family</replaceable>}{<replaceable>series</replaceable>}{<replaceable>shape</replaceable>}</literal>
+<anchor id="low-level-font-commands-usefont"/></listitem></varlistentry><varlistentry><term><literal>\usefont{<replaceable>enc</replaceable>}{<replaceable>family</replaceable>}{<replaceable>series</replaceable>}{<replaceable>shape</replaceable>}</literal>
 </term><listitem><indexterm role="fn"><primary>\usefont</primary></indexterm>
 <para>The same as invoking <literal>\fontencoding</literal>, <literal>\fontfamily</literal>,
 <literal>\fontseries</literal> and <literal>\fontshape</literal> with the given parameters,
@@ -1833,12 +1894,15 @@
 <indexterm role="fn"><primary>\onecolumn</primary></indexterm>
 <indexterm role="cp"><primary>one-column output</primary></indexterm>
 
+<para>Synopsis:
+</para>
+<screen>\onecolumn
+</screen>
 <para>Start a new page and produce single-column output.  If the document is
 given the class option <literal>onecolumn</literal> then this is the default
-behavior (see <link linkend="Document-class-options">Document class options</link>).
+behavior (see <link linkend="Document-class-options">Document class options</link>).  This command is fragile
+(see <link linkend="_005cprotect">\protect</link>).
 </para>
-<para>This command is fragile (see <link linkend="_005cprotect">\protect</link>).
-</para>
 
 </sect1>
 <sect1 label="5.2" id="_005ctwocolumn">
@@ -1855,31 +1919,30 @@
 </screen>
 <para>Start a new page and produce two-column output. If the document is given
 the class option <literal>twocolumn</literal> then this is the default
-(see <link linkend="Document-class-options">Document class options</link>).
+(see <link linkend="Document-class-options">Document class options</link>).  This command is fragile
+(see <link linkend="_005cprotect">\protect</link>).
 </para>
 <para>If the optional <replaceable>prelim one column text</replaceable> argument
 is present, it is typeset in one-column mode before the two-column
 typesetting starts.
 </para>
-<para>This command is fragile (see <link linkend="_005cprotect">\protect</link>).
-</para>
 <para>These parameters control typesetting in two-column output:
 </para>
 <variablelist><varlistentry><term><indexterm role="fn"><primary>\columnsep</primary></indexterm><literal>\columnsep</literal>
-</term><listitem><para>The distance between columns. The default is 35pt.  Change it with a
+</term><listitem><anchor id="twocolumn-columnsep"/><para>The distance between columns. The default is 35pt.  Change it with a
 command such as <literal>\setlength{\columnsep}{40pt}</literal> You must change
 it before the two column environment starts; in the preamble is a good
 place.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\columnseprule</primary></indexterm><literal>\columnseprule</literal>
-</term><listitem><para>The width of the rule between columns. The rule appears halfway between
+</term><listitem><anchor id="twocolumn-columnseprule"/><para>The width of the rule between columns. The rule appears halfway between
 the two columns.  The default is 0pt, meaning that there is no rule.
 Change it with a command such as
 <literal>\setlength{\columnseprule}{0.4pt}</literal>, before the two-column
 environment starts.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\columnwidth</primary></indexterm><literal>\columnwidth</literal>
-</term><listitem><para>The width of a single column.  In one-column mode this is equal to
+</term><listitem><anchor id="twocolumn-columnwidth"/><para>The width of a single column.  In one-column mode this is equal to
 <literal>\textwidth</literal>.  In two-column mode by default &latex; sets the
 width of each of the two columns to be half of <literal>\textwidth</literal> minus
 <literal>\columnsep</literal>.
@@ -1891,7 +1954,7 @@
 and see <link linkend="table">table</link>). &latex; places starred floats at the top of a page.
 The following parameters control float behavior of two-column output.
 </para>
-<variablelist><varlistentry><term><indexterm role="fn"><primary>\dbltopfraction</primary></indexterm><literal>\dbltopfraction</literal>
+<variablelist><anchor id="twocolumn-dbltopfraction"/><varlistentry><term><indexterm role="fn"><primary>\dbltopfraction</primary></indexterm><literal>\dbltopfraction</literal>
 </term><listitem><para>The maximum fraction at the top of a two-column page that may be
 occupied by two-column wide floats.  The default is 0.7, meaning that
 the height of a <literal>table*</literal> or <literal>figure*</literal> environment must not
@@ -1908,27 +1971,27 @@
 </listitem><listitem><para>Increase the value of <literal>\dbltopfraction</literal> to a suitably large number,
 to avoid going to float pages so soon.
 </para></listitem></itemizedlist>
-<para>You can redefine it, for instance with
+<para>You can redefine it, as with
 <literal>\renewcommand{\dbltopfraction}{0.9}</literal>.
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\dblfloatpagefraction</primary></indexterm><literal>\dblfloatpagefraction</literal>
+<anchor id="twocolumn-dblfloatpagefraction"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\dblfloatpagefraction</primary></indexterm><literal>\dblfloatpagefraction</literal>
 </term><listitem><para>For a float page of two-column wide floats, this is the minimum fraction
 that must be occupied by floats, limiting the amount of blank space.
 &latex;’s default is <literal>0.5</literal>.  Change it with <literal>\renewcommand</literal>.
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\dblfloatsep</primary></indexterm><literal>\dblfloatsep</literal>
+<anchor id="twocolumn-dblfloatsep"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\dblfloatsep</primary></indexterm><literal>\dblfloatsep</literal>
 </term><listitem><para>On a float page of two-column wide floats, this length is the distance
 between floats, at both the top and bottom of the page.  The default is
 <literal>12pt plus2pt minus2pt</literal> for a document set at <literal>10pt</literal> or
 <literal>11pt</literal>, and <literal>14pt plus2pt minus4pt</literal> for a document set at
 <literal>12pt</literal>.
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\dbltextfloatsep</primary></indexterm><literal>\dbltextfloatsep</literal>
+<anchor id="twocolumn-dbltextfloatsep"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\dbltextfloatsep</primary></indexterm><literal>\dbltextfloatsep</literal>
 </term><listitem><para>This length is the distance between a multi-column float at the top or
 bottom of a page and the main text.  The default is <literal>20pt plus2pt
 minus4pt</literal>.
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\dbltopnumber</primary></indexterm><literal>\dbltopnumber</literal>
+<anchor id="twocolumn-dbltopnumber"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\dbltopnumber</primary></indexterm><literal>\dbltopnumber</literal>
 </term><listitem><para>On a float page of two-column wide floats, this counter gives the
 maximum number of floats allowed at the top of the page.  The &latex;
 default is <literal>2</literal>.
@@ -2015,20 +2078,20 @@
 </term><listitem><indexterm role="fn"><primary>\columnsep</primary></indexterm>
 <indexterm role="fn"><primary>\columnseprule</primary></indexterm>
 <indexterm role="fn"><primary>\columnwidth</primary></indexterm>
-<para>The distance between the two columns, the width of a rule between the
+<anchor id="page-layout-parameters-columnsep"/><anchor id="page-layout-parameters-columnseprule"/><anchor id="page-layout-parameters-columnwidth"/><para>The distance between the two columns, the width of a rule between the
 columns, and the width of the columns, when the document class option
 <literal>twocolumn</literal> is in effect (see <link linkend="Document-class-options">Document class options</link>).
 See <link linkend="_005ctwocolumn">\twocolumn</link>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\headheight</primary></indexterm><literal>\headheight</literal>
 </term><listitem><indexterm role="fn"><primary>\headheight</primary></indexterm>
-<para>Height of the box that contains the running head.  The default in the
+<anchor id="page-layout-parameters-headheight"/><para>Height of the box that contains the running head.  The default in the
 <literal>article</literal>, <literal>report</literal>, and <literal>book</literal> classes is ‘<literal>12pt</literal>’,
 at all type sizes.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\headsep</primary></indexterm><literal>\headsep</literal>
 </term><listitem><indexterm role="fn"><primary>\headsep</primary></indexterm>
-<para>Vertical distance between the bottom of the header line and the top of
+<anchor id="page-layout-parameters-headsep"/><para>Vertical distance between the bottom of the header line and the top of
 the main text.  The default in the <literal>article</literal> and <literal>report</literal>
 classes is ‘<literal>25pt</literal>’.  In the <literal>book</literal> class the default is: if the
 document is set at 10pt then it is ‘<literal>0.25in</literal>’, and at 11pt and 12pt
@@ -2036,7 +2099,7 @@
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\footskip</primary></indexterm><literal>\footskip</literal>
 </term><listitem><indexterm role="fn"><primary>\footskip</primary></indexterm>
-<para>Distance from the baseline of the last line of text to the baseline of
+<anchor id="page-layout-parameters-footskip"/><para>Distance from the baseline of the last line of text to the baseline of
 the page footer.  The default in the <literal>article</literal> and <literal>report</literal>
 classes is ‘<literal>30pt</literal>’.  In the <literal>book</literal> class the default is: when
 the type size is 10pt the default is ‘<literal>0.35in</literal>’, while at 11pt it is
@@ -2044,7 +2107,7 @@
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\linewidth</primary></indexterm><literal>\linewidth</literal>
 </term><listitem><indexterm role="fn"><primary>\linewidth</primary></indexterm>
-<para>Width of the current line, decreased for each nested <literal>list</literal>
+<anchor id="page-layout-parameters-linewidth"/><para>Width of the current line, decreased for each nested <literal>list</literal>
 (see <link linkend="list">list</link>).  That is, the nominal value for <literal>\linewidth</literal> is to
 equal <literal>\textwidth</literal> but for each nested list the <literal>\linewidth</literal>
 is decreased by the sum of that list’s <literal>\leftmargin</literal> and
@@ -2059,7 +2122,7 @@
 </term><listitem><indexterm role="fn"><primary>\marginparpush</primary></indexterm>
 <indexterm role="fn"><primary>\marginsep</primary></indexterm>
 <indexterm role="fn"><primary>\marginparwidth</primary></indexterm>
-<para>The minimum vertical space between two marginal notes, the horizontal
+<anchor id="page-layout-parameters-marginparpush"/><anchor id="page-layout-parameters-marginsep"/><anchor id="page-layout-parameters-marginparwidth"/><para>The minimum vertical space between two marginal notes, the horizontal
 space between the text body and the marginal notes, and the horizontal
 width of the notes.
 </para>
@@ -2087,7 +2150,7 @@
 </term><term><indexterm role="fn"><primary>\evensidemargin</primary></indexterm><literal>\evensidemargin</literal>
 </term><listitem><indexterm role="fn"><primary>\oddsidemargin</primary></indexterm>
 <indexterm role="fn"><primary>\evensidemargin</primary></indexterm>
-<para>The <literal>\oddsidemargin</literal> is the extra distance between the left side of
+<anchor id="page-layout-parameters-oddsidemargin"/><anchor id="page-layout-parameters-evensidemargin"/><para>The <literal>\oddsidemargin</literal> is the extra distance between the left side of
 the page and the text’s left margin, on odd-numbered pages when the
 document class option <literal>twoside</literal> is chosen and on all pages when
 <literal>oneside</literal> is in effect.  When <literal>twoside</literal> is in effect, on
@@ -2100,21 +2163,21 @@
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\paperheight</primary></indexterm><literal>\paperheight</literal>
 </term><listitem><indexterm role="fn"><primary>\paperheight</primary></indexterm>
-<para>The height of the paper, as distinct from the height of the print area.
-It is normally set with a document class option, as in
+<anchor id="page-layout-parameters-paperheight"/><para>The height of the paper, as distinct from the height of the print area.
+Normally set with a document class option, as in
 <literal>\documentclass[a4paper]{article}</literal> (see <link linkend="Document-class-options">Document class
 options</link>).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\paperwidth</primary></indexterm><literal>\paperwidth</literal>
 </term><listitem><indexterm role="fn"><primary>\paperwidth</primary></indexterm>
-<para>The width of the paper, as distinct from the width of the print area.
-It is normally set with a document class option, as in
+<anchor id="page-layout-parameters-paperwidth"/><para>The width of the paper, as distinct from the width of the print area.
+Normally set with a document class option, as in
 <literal>\documentclass[a4paper]{article}</literal> (see <link linkend="Document-class-options">Document class
 options</link>).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textheight</primary></indexterm><literal>\textheight</literal>
 </term><listitem><indexterm role="fn"><primary>\textheight</primary></indexterm>
-<para>The normal vertical height of the page body.  If the document is set at
+<anchor id="page-layout-parameters-textheight"/><para>The normal vertical height of the page body.  If the document is set at
 a nominal type size of 10pt then for an <literal>article</literal> or <literal>report</literal>
 the default is ‘<literal>43\baselineskip</literal>’, while for a <literal>book</literal> it is
 ‘<literal>41\baselineskip</literal>’.  At a type size of 11pt the default is
@@ -2123,7 +2186,7 @@
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textwidth</primary></indexterm><literal>\textwidth</literal>
 </term><listitem><indexterm role="fn"><primary>\textwidth</primary></indexterm>
-<para>The full horizontal width of the entire page body.  For an
+<anchor id="page-layout-parameters-textwidth"/><para>The full horizontal width of the entire page body.  For an
 <literal>article</literal> or <literal>report</literal> document, the default is ‘<literal>345pt</literal>’
 when the chosen type size is 10pt, the default is ‘<literal>360pt</literal>’ at 11pt,
 and it is ‘<literal>390pt</literal>’ at 12pt.  For a <literal>book</literal> document, the default
@@ -2143,14 +2206,14 @@
 <literal>minipage</literal> or <literal>\parbox</literal>.
 </para>
 <indexterm role="fn"><primary>\hsize</primary></indexterm>
-<indexterm role="fn"><primary>\hsize</primary></indexterm>
-<para>This entry is included for completeness: <literal>\hsize</literal> is the &tex;
+<anchor id="page-layout-parameters-hsize"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\hsize</primary></indexterm><literal>\hsize</literal>
+</term><listitem><para>This entry is included for completeness: <literal>\hsize</literal> is the &tex;
 primitive parameter used when text is broken into lines.  It should not
 be used in normal &latex; documents.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\topmargin</primary></indexterm><literal>\topmargin</literal>
 </term><listitem><indexterm role="fn"><primary>topmargin</primary></indexterm>
-<para>Space between the top of the &tex; page (one inch from the top of the
+<anchor id="page-layout-parameters-topmargin"/><para>Space between the top of the &tex; page (one inch from the top of the
 paper, by default) and the top of the header.  The value is computed
 based on many other parameters: <literal>\paperheight − 2in −
 \headheight − \headsep − \textheight − \footskip</literal>,
@@ -2158,7 +2221,7 @@
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\topskip</primary></indexterm><literal>\topskip</literal>
 </term><listitem><indexterm role="fn"><primary>\topskip</primary></indexterm>
-<para>Minimum distance between the top of the page body and the baseline of
+<anchor id="page-layout-parameters-topskip"/><para>Minimum distance between the top of the page body and the baseline of
 the first line of text.  For the standard classes, the default is the
 same as the font size, e.g., ‘<literal>10pt</literal>’ at a type size of 10pt.
 </para>
@@ -2272,65 +2335,67 @@
 </para>
 <variablelist><varlistentry><term><indexterm role="fn"><primary>\bottomfraction</primary></indexterm><literal>\bottomfraction</literal>
 </term><listitem><indexterm role="fn"><primary>\bottomfraction</primary></indexterm>
-<para>The maximum fraction of the page allowed to be occupied by floats at
+<anchor id="floats-bottomfraction"/><para>The maximum fraction of the page allowed to be occupied by floats at
 the bottom; default ‘<literal>.3</literal>’.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\floatpagefraction</primary></indexterm><literal>\floatpagefraction</literal>
 </term><listitem><indexterm role="fn"><primary>\floatpagefraction</primary></indexterm>
-<para>The minimum fraction of a float page that must be occupied by floats;
+<anchor id="floats-floatpagefraction"/><para>The minimum fraction of a float page that must be occupied by floats;
 default ‘<literal>.5</literal>’.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textfraction</primary></indexterm><literal>\textfraction</literal>
 </term><listitem><indexterm role="fn"><primary>\textfraction</primary></indexterm>
-<para>Minimum fraction of a page that must be text; if floats take up too
+<anchor id="floats-textfraction"/><para>Minimum fraction of a page that must be text; if floats take up too
 much space to preserve this much text, floats will be moved to a
 different page.  The default is ‘<literal>.2</literal>’.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\topfraction</primary></indexterm><literal>\topfraction</literal>
 </term><listitem><indexterm role="fn"><primary>\topfraction</primary></indexterm>
-<para>Maximum fraction at the top of a page that may be occupied before
+<anchor id="floats-topfraction"/><para>Maximum fraction at the top of a page that may be occupied before
 floats; default ‘<literal>.7</literal>’.
 </para></listitem></varlistentry></variablelist>
-<para>Parameters relating to vertical space around floats (change them with
-<literal>\setlength{<replaceable>parameter</replaceable>}{<replaceable>length expression</replaceable>}</literal>):
+<para>Parameters relating to vertical space around floats (change them with a
+command of the form <literal>\setlength{<replaceable>parameter</replaceable>}{<replaceable>length
+expression</replaceable>}</literal>):
 </para>
 <variablelist><varlistentry><term><indexterm role="fn"><primary>\floatsep</primary></indexterm><literal>\floatsep</literal>
 </term><listitem><indexterm role="fn"><primary>\floatsep</primary></indexterm>
-<para>Space between floats at the top or bottom of a page; default
+<anchor id="floats-floatsep"/><para>Space between floats at the top or bottom of a page; default
 ‘<literal>12pt plus2pt minus2pt</literal>’.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\intextsep</primary></indexterm><literal>\intextsep</literal>
 </term><listitem><indexterm role="fn"><primary>\intextsep</primary></indexterm>
-<para>Space above and below a float in the middle of the main text; default
+<anchor id="floats-intextsep"/><para>Space above and below a float in the middle of the main text; default
 ‘<literal>12pt plus2pt minus2pt</literal>’ for 10 point and 11 point documents,
 and ‘<literal>14pt plus4pt minus4pt</literal>’ for 12 point documents.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textfloatsep</primary></indexterm><literal>\textfloatsep</literal>
 </term><listitem><indexterm role="fn"><primary>\textfloatsep</primary></indexterm>
-<para>Space between the last (first) float at the top (bottom) of a page;
+<anchor id="floats-textfloatsep"/><para>Space between the last (first) float at the top (bottom) of a page;
 default ‘<literal>20pt plus2pt minus4pt</literal>’.
 </para></listitem></varlistentry></variablelist>
-<para>Counters relating to the number of floats on a page (change them with
-<literal>\setcounter{<replaceable>ctrname</replaceable>}{<replaceable>natural number</replaceable>}</literal>):
+<para>Counters relating to the number of floats on a page (change them with a
+command of the form <literal>\setcounter{<replaceable>ctrname</replaceable>}{<replaceable>natural
+number</replaceable>}</literal>):
 </para>
 <variablelist><varlistentry><term><indexterm role="fn"><primary>bottomnumber</primary></indexterm><literal>bottomnumber</literal>
 </term><listitem><indexterm role="fn"><primary>bottomnumber</primary></indexterm>
-<para>Maximum number of floats that can appear at the bottom of a text page;
+<anchor id="floats-bottomnumber"/><para>Maximum number of floats that can appear at the bottom of a text page;
 default 1.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>dbltopnumber</primary></indexterm><literal>dbltopnumber</literal>
 </term><listitem><indexterm role="fn"><primary>dbltopnumber</primary></indexterm>
-<para>Maximum number of full-sized floats that can appear at the top of a
+<anchor id="floats-dbltopnumber"/><para>Maximum number of full-sized floats that can appear at the top of a
 two-column page; default 2.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>topnumber</primary></indexterm><literal>topnumber</literal>
 </term><listitem><indexterm role="fn"><primary>topnumber</primary></indexterm>
-<para>Maximum number of floats that can appear at the top of a text page;
+<anchor id="floats-topnumber"/><para>Maximum number of floats that can appear at the top of a text page;
 default 2.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>totalnumber</primary></indexterm><literal>totalnumber</literal>
 </term><listitem><indexterm role="fn"><primary>totalnumber</primary></indexterm>
-<para>Maximum number of floats that can appear on a text page; default 3.
+<anchor id="floats-totalnumber"/><para>Maximum number of floats that can appear on a text page; default 3.
 </para></listitem></varlistentry></variablelist>
 <para>The principal &tex; FAQ entry relating to floats
 <ulink url="http://www.tex.ac.uk/cgi-bin/texfaq2html?label=floats">http://www.tex.ac.uk/cgi-bin/texfaq2html?label=floats</ulink> contains
@@ -2348,67 +2413,624 @@
 <title>Sectioning</title>
 
 <indexterm role="cp"><primary>sectioning commands</primary></indexterm>
+<indexterm role="cp"><primary>part</primary></indexterm>
+<indexterm role="cp"><primary>chapter</primary></indexterm>
+<indexterm role="cp"><primary>section</primary></indexterm>
+<indexterm role="cp"><primary>subsection</primary></indexterm>
+<indexterm role="cp"><primary>paragraph</primary></indexterm>
+<indexterm role="cp"><primary>subparagraph</primary></indexterm>
+<indexterm role="fn"><primary>\part</primary></indexterm>
+<indexterm role="fn"><primary>\chapter</primary></indexterm>
+<indexterm role="fn"><primary>\section</primary></indexterm>
+<indexterm role="fn"><primary>\subsection</primary></indexterm>
+<indexterm role="fn"><primary>\paragraph</primary></indexterm>
+<indexterm role="fn"><primary>\subparagraph</primary></indexterm>
 
-<para>Sectioning commands provide the means to structure your text into units:
+<para>Structure your text into divisions: parts, chapters, sections, etc.  All
+sectioning commands have the same form, one of:
 </para>
-<variablelist><varlistentry><term><indexterm role="fn"><primary>\part</primary></indexterm><literal>\part</literal>
-</term></varlistentry><varlistentry><term><indexterm role="fn"><primary>\chapter</primary></indexterm><literal>\chapter</literal>
-</term><listitem><para>(<literal>report</literal> and <literal>book</literal> class only)
-</para></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\section</primary></indexterm><literal>\section</literal>
-</term></varlistentry><varlistentry><term><indexterm role="fn"><primary>\subsection</primary></indexterm><literal>\subsection</literal>
-</term></varlistentry><varlistentry><term><indexterm role="fn"><primary>\subsubsection</primary></indexterm><literal>\subsubsection</literal>
-</term></varlistentry><varlistentry><term><indexterm role="fn"><primary>\paragraph</primary></indexterm><literal>\paragraph</literal>
-</term></varlistentry><varlistentry><term><indexterm role="fn"><primary>\subparagraph</primary></indexterm><literal>\subparagraph</literal>
-</term></varlistentry></variablelist>
-<para>All sectioning commands take the same general form, e.g.,
-</para>
-<screen>\chapter[<replaceable>toctitle</replaceable>]{<replaceable>title</replaceable>}
+<screen><replaceable>sectioning-command</replaceable>{<replaceable>title</replaceable>}
+<replaceable>sectioning-command</replaceable>*{<replaceable>title</replaceable>}
+<replaceable>sectioning-command</replaceable>[<replaceable>toc-title</replaceable>]{<replaceable>title</replaceable>}
 </screen>
-<para>In addition to providing the heading <replaceable>title</replaceable> in the main text, the
-section title can appear in two other places:
+<para>For instance, declare the start of a subsection as with
+<literal>\subsection{Motivation}</literal>.
 </para>
-<orderedlist numeration="arabic"><listitem><para>The table of contents.
-</para></listitem><listitem><para>The running head at the top of the page.
-</para></listitem></orderedlist>
-<para>You may not want the same text in these places as in the main text.
-To handle this, the sectioning commands have an optional argument
-<replaceable>toctitle</replaceable> that, when given, specifies the text for these other
-places.
+<para>The table has each <replaceable>sectioning-command</replaceable> in &latex;.  All are
+available in all of &latex;’s standard document classes <literal>book</literal>,
+<literal>report</literal>, and <literal>article</literal>, except that <literal>\chapter</literal> is
+not available in <literal>article</literal>.
 </para>
+<informaltable><tgroup cols="3"><colspec colwidth="25*"></colspec><colspec colwidth="25*"></colspec><colspec colwidth="40*"></colspec><thead><row><entry><para>Sectioning unit  </para></entry><entry><para>Command  </para></entry><entry><para>Level 
+</para></entry></row></thead><tbody><row><entry><para>Part
+</para></entry><entry><para><literal>\part</literal>  </para></entry><entry><para>-1 (<literal>book</literal>, <literal>report</literal>), 0 (<literal>article</literal>)
+</para></entry></row><row><entry><para>Chapter
+</para></entry><entry><para><literal>\chapter</literal>   </para></entry><entry><para>0
+</para></entry></row><row><entry><para>Section
+</para></entry><entry><para><literal>\section</literal>   </para></entry><entry><para>1 
+</para></entry></row><row><entry><para>Subsection
+</para></entry><entry><para><literal>\subsection</literal>   </para></entry><entry><para>2 
+</para></entry></row><row><entry><para>Subsubsection
+</para></entry><entry><para><literal>\subsubsection</literal>   </para></entry><entry><para>3  
+</para></entry></row><row><entry><para>Paragraph
+</para></entry><entry><para><literal>\paragraph</literal>   </para></entry><entry><para>4  
+</para></entry></row><row><entry><para>Subparagraph
+</para></entry><entry><para><literal>\subparagraph</literal>   </para></entry><entry><para>5  
+</para></entry></row></tbody></tgroup></informaltable>
 <indexterm role="cp"><primary><literal>*</literal>-form of sectioning commands</primary></indexterm>
-<para>Also, all sectioning commands have <literal>*</literal>-forms that print
-<replaceable>title</replaceable> as usual, but do not include a number and do not make an
-entry in the table of contents.  For instance:
+<para>All these commands have a <literal>*</literal>-form that prints <replaceable>title</replaceable> as usual
+but is not numbered and does not make an entry in the table of contents.
+An example of using this is for an appendix in an <literal>article</literal> .  The
+input <literal>\appendix\section{Appendix}</literal> gives the output ‘<literal>A
+Appendix</literal>’ (see <link linkend="_005cappendix">\appendix</link>).  You can lose the numbering ‘<literal>A</literal>’
+by instead entering <literal>\section*{Appendix}</literal> (articles often omit a
+table of contents and have simple page headers so the other differences
+from the <literal>\section</literal> command may not matter).
 </para>
-<screen>\section*{Preamble}
+<para>The section title <replaceable>title</replaceable> provides the heading in the main text, but
+it may also appear in the table of contents and in the running head or
+foot (see <link linkend="Page-styles">Page styles</link>).  You may not want the same text in these
+places as in the main text.  All of these commands have an optional
+argument <replaceable>toc-title</replaceable> for these other places.
+</para>
+<para>The level number in the table above determines which sectional units are
+numbered, and which appear in the table of contents.  If the sectioning
+command’s <replaceable>level</replaceable> is less than or equal to the value of the counter
+<literal>secnumdepth</literal> then the titles for this sectioning command will be
+numbered (see <link linkend="Sectioning_002fsecnumdepth">Sectioning/secnumdepth</link>).  And, if <replaceable>level</replaceable> is less
+than or equal to the value of the counter <literal>tocdepth</literal> then the table
+of contents will have an entry for this sectioning unit
+(see <link linkend="Sectioning_002ftocdepth">Sectioning/tocdepth</link>).
+</para>
+<para>&latex; expects that before you have a <literal>\subsection</literal> you will have
+a <literal>\section</literal> and, in a book, that before a <literal>\section</literal> you will
+have a <literal>\chapter</literal>.  Otherwise you can get a something like a
+subsection numbered ‘<literal>3.0.1</literal>’.
+</para>
+<para>Two counters relate to the appearance of sectioning commands.
+</para>
+<variablelist><varlistentry><term><indexterm role="fn"><primary>secnumdepth</primary></indexterm><literal>secnumdepth</literal>
+</term><listitem><indexterm role="fn"><primary>secnumdepth counter</primary></indexterm>
+<indexterm role="cp"><primary>section numbers, printing</primary></indexterm>
+<anchor id="sectioning-secnumdepth"/><anchor id="Sectioning_002fsecnumdepth"/><para>Controls which sectioning commands are
+numbered.  Suppress numbering of sectioning at any depth greater than
+<replaceable>level</replaceable> <literal>\setcounter{secnumdepth}{<replaceable>level</replaceable>}</literal>
+(see <link linkend="_005csetcounter">\setcounter</link>).  See the above table for the level numbers.  For
+instance, if the <literal>secnumdepth</literal> is 1 in an <literal>article</literal> then a
+<literal>\section{Introduction}</literal> command will produce output like ‘<literal>1
+Introduction</literal>’ while <literal>\subsection{Discussion}</literal> will produce output
+like ‘<literal>Discussion</literal>’, without the number. &latex;’s default
+<literal>secnumdepth</literal> is 3 in <filename>article</filename> class and  2 in the
+<filename>book</filename> and <filename>report</filename> classes.
+</para>
+</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>tocdepth</primary></indexterm><literal>tocdepth</literal>
+</term><listitem><indexterm role="fn"><primary>tocdepth counter</primary></indexterm>
+<indexterm role="cp"><primary>table of contents, sectioning numbers printed</primary></indexterm>
+<anchor id="sectioning-tocdepth"/><anchor id="Sectioning_002ftocdepth"/><para>Controls which sectioning units are listed in the table of contents.
+The setting <literal>\setcounter{tocdepth}{<replaceable>level</replaceable>}</literal> makes the
+sectioning units at <replaceable>level</replaceable> be the smallest ones listed
+(see <link linkend="_005csetcounter">\setcounter</link>).  See the above table for the level numbers.  For
+instance, if <literal>tocdepth</literal> is 1 then the table of contents will
+list sections but not subsections.  &latex;’s default
+<literal>secnumdepth</literal> is 3 in <filename>article</filename> class and  2 in the
+<filename>book</filename> and <filename>report</filename> classes.
+</para>
+</listitem></varlistentry></variablelist>
+
+
+<sect1 label="6.1" id="_005cpart">
+<title><literal>\part</literal></title>
+
+<indexterm role="fn"><primary>\part</primary></indexterm>
+<indexterm role="cp"><primary>part</primary></indexterm>
+<indexterm role="cp"><primary>sectioning, part</primary></indexterm>
+
+<para>Synopsis, one of:
+</para>
+<screen>\part{<replaceable>title</replaceable>}
+\part*{<replaceable>title</replaceable>}
+\part[<replaceable>toc-title</replaceable>]{<replaceable>title</replaceable>}
 </screen>
+<para>Start a document part.  The standard &latex; classes <literal>book</literal>,
+<literal>report</literal>, and <literal>article</literal>, all have this command.
+</para>
+<para>This produces a document part, in a book.
+</para>
+<screen>\part{VOLUME I \\
+       PERSONAL MEMOIRS OF  U.\ S.\ GRANT}
+\chapter{ANCESTRY--BIRTH--BOYHOOD.}
+My family is American, and has been for generations,
+in all its branches, direct and collateral.
+</screen>
+<para>In each standard class the <literal>\part</literal> command outputs a part number
+such as ‘<literal>Part I</literal>’, alone on its line, in boldface, and in large
+type.  Then &latex; outputs <replaceable>title</replaceable>, also alone on its line, in
+bold and in even larger type.  In class <literal>book</literal>, the &latex;
+default puts each part alone on its own page. If the book is two-sided
+then &latex; will skip a page if needed to have the new part on an
+odd-numbered page.  In <literal>report</literal> it is again alone on a page, but
+&latex; won’t force it onto an odd-numbered page.  In an <literal>article</literal>
+&latex; does not put it on a fresh page, but instead outputs the part
+number and part title onto the main document page.
+</para>
+<para>The <literal>*</literal> form shows <replaceable>title</replaceable> 
+but it does not show the part number, does not increment the
+<literal>part</literal> counter, and produces no table of contents entry.
+</para>
+<para>The optional argument <replaceable>toc-title</replaceable> will appear as the part title in
+the table of contents (see <link linkend="Table-of-contents-etc_002e">Table of contents etc.</link>) and in running
+headers (see <link linkend="Page-styles">Page styles</link>).  If it is not present then <replaceable>title</replaceable>
+will be there.  This example puts a line break in <replaceable>title</replaceable> but leaves
+out the break in the table of contents.
+</para>
+<screen>\part[Up from the bottom; my life]{Up from the bottom\\ my life}
+</screen>
+<para>For determining which sectional units are numbered and which appear in
+the table of contents, the level number of a part is -1
+(see <link linkend="Sectioning_002fsecnumdepth">Sectioning/secnumdepth</link> and see <link linkend="Sectioning_002ftocdepth">Sectioning/tocdepth</link>).
+</para>
+<indexterm role="cp"><primary>package, <literal>indentfirst</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>indentfirst</literal> package</primary></indexterm>
+
+<para>In the class <literal>article</literal>, if a paragraph immediately follows the part
+title then it is not indented.  To get an indent you can use the package
+<filename>indentfirst</filename>.
+</para>
+<indexterm role="cp"><primary>package, <literal>titlesec</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>titlesec</literal> package</primary></indexterm>
+
+<para>One package to change the behavior of <literal>\part</literal> is <filename>titlesec</filename>.
+See its documentation on CTAN.
+</para>
+
+</sect1>
+<sect1 label="6.2" id="_005cchapter">
+<title><literal>\chapter</literal></title>
+
+<indexterm role="fn"><primary>\chapter</primary></indexterm>
+<indexterm role="cp"><primary>chapter</primary></indexterm>
+
+<para>Synopsis, one of:
+</para>
+<screen>\chapter{<replaceable>title</replaceable>}
+\chapter*{<replaceable>title</replaceable>}
+\chapter[<replaceable>toc-title</replaceable>]{<replaceable>title</replaceable>}
+</screen>
+<para>Start a chapter.  The standard &latex; classes <literal>book</literal> and
+<literal>report</literal> have this command but <literal>article</literal> does not.
+</para>
+<para>This produces a chapter.
+</para>
+<screen>\chapter{Loomings}
+Call me Ishmael.
+Some years ago---never mind how long precisely---having little or no
+money in my purse, and nothing particular to interest me on shore, I
+thought I would sail about a little and see the watery part of
+the world.
+</screen>
+<para>The &latex; default starts each chapter on a fresh page, an
+odd-numbered page if the document is two-sided.  It produces a chapter
+number such as ‘<literal>Chapter 1</literal>’ in large boldface type (the size is
+<literal>\huge</literal>).  It then puts <replaceable>title</replaceable> on a fresh line, in boldface
+type that is still larger (size <literal>\Huge</literal>).  It also increments the
+<literal>chapter</literal> counter, adds an entry to the table of contents
+(see <link linkend="Table-of-contents-etc_002e">Table of contents etc.</link>), and sets the running header
+information (see <link linkend="Page-styles">Page styles</link>).
+</para>
+<para>The <literal>*</literal> form shows <replaceable>title</replaceable> on a fresh line, in boldface.
+But it does not show the chapter number, does not increment the
+<literal>chapter</literal> counter, produces no table of contents entry, and does
+not affect the running header.  (If you use the page style
+<literal>headings</literal> in a two-sided document then the header will be from the
+prior chapter.)  This example illustrates.
+</para>
+<screen>\chapter*{Preamble}
+</screen>
+<para>The optional argument <replaceable>toc-title</replaceable> will appear as the chapter title
+in the table of contents (see <link linkend="Table-of-contents-etc_002e">Table of contents etc.</link>) and in
+running headers (see <link linkend="Page-styles">Page styles</link>).  If it is not present then
+<replaceable>title</replaceable> will be there.  This shows the full name in the chapter
+title,
+</para>
+<screen>\chapter[Weyl]{Hermann Klaus Hugo (Peter) Weyl (1885--1955)}
+</screen>
+<para>but only ‘<literal>Weyl</literal>’ on the contents page.  This puts a line break in
+the title but that doesn’t work well with running headers so it omits
+the break in the contents
+</para>
+<screen>\chapter[Given it all\\ my story]{Given it all\\ my story}
+</screen>
+<para>For determining which sectional units are numbered and which appear in
+the table of contents, the level number of a chapter is 0
+(see <link linkend="Sectioning_002fsecnumdepth">Sectioning/secnumdepth</link> and see <link linkend="Sectioning_002ftocdepth">Sectioning/tocdepth</link>).
+</para>
+<indexterm role="cp"><primary>package, <literal>indentfirst</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>indentfirst</literal> package</primary></indexterm>
+
+<para>The paragraph that follows the chapter title is not indented, as is a
+standard typographical practice.  To get an indent use the package
+<filename>indentfirst</filename>.
+</para>
+<para>You can change what is shown for the chapter number.  To change it to
+something like ‘<literal>Lecture 1</literal>’, put in the preamble either
+<literal>\renewcommand{\chaptername}{Lecture}</literal> or this
+(see <link linkend="_005cmakeatletter-_0026-_005cmakeatother">\makeatletter & \makeatother</link>).
+</para>
+<screen>\makeatletter
+\renewcommand{\@chapapp}{Lecture}
+\makeatother
+</screen>
+<indexterm role="cp"><primary>package, <literal>babel</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>babel</literal> package</primary></indexterm>
+
+<para>To make this change because of the primary language for
+the document, see the package <filename>babel</filename>.
+</para>
+<para>In a two-sided document &latex; puts a chapter on odd-numbered page, if
+necessary leaving an even-numbered page that is blank except for any
+running headers.  To make that page completely blank,
+see <link linkend="_005cclearpage-_0026-_005ccleardoublepage">\clearpage & \cleardoublepage</link>.
+</para>
+<indexterm role="cp"><primary>package, <literal>titlesec</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>titlesec</literal> package</primary></indexterm>
+
+<para>To change the behavior of the <literal>\chapter</literal> command, you can copy its
+definition from the &latex; format file and make adjustments.  But
+there are also many packages on CTAN that address this.  One is
+<filename>titlesec</filename>.  See its documentation, but the example below gives a
+sense of what it can do.
+</para>
+<screen>\usepackage{titlesec}   % in preamble
+\titleformat{\chapter}
+  {\Huge\bfseries}  % format of title
+  {}                % label, such as 1.2 for a subsection
+  {0pt}             % length of separation between label and title
+  {}                % before-code hook
+</screen>
+<para>This omits the chapter number ‘<literal>Chapter 1</literal>’ from the page but unlike
+<literal>\chapter*</literal> it keeps the chapter in the table of contents and the
+running headers.
+</para>
+
+</sect1>
+<sect1 label="6.3" id="_005csection">
+<title><literal>\section</literal></title>
+
+<indexterm role="fn"><primary>\section</primary></indexterm>
+<indexterm role="cp"><primary>section</primary></indexterm>
+
+<para>Synopsis, one of:
+</para>
+<screen>\section{<replaceable>title</replaceable>}
+\section*{<replaceable>title</replaceable>}
+\section[<replaceable>toc-title</replaceable>]{<replaceable>title</replaceable>}
+</screen>
+<para>Start a section.  The standard &latex; classes <literal>article</literal>,
+<literal>book</literal>, and <literal>report</literal> all have this command.
+</para>
+<para>This produces a section.
+</para>
+<screen>In this Part we tend to be more interested in the function,
+in the input-output behavior,
+than in the details of implementing that behavior.
+
+\section{Turing machines}
+Despite this desire to downplay implementation,
+we follow the approach of A~Turing that the
+first step toward defining the set of computable functions
+is to reflect on the details of what mechanisms can do.
+</screen>
+<para>For the standard &latex; classes <literal>book</literal> and <literal>report</literal> the
+default output is like ‘<literal>1.2 <replaceable>title</replaceable></literal>’ (for chapter 1,
+section 2), alone on its line and flush left, in boldface and a
+larger type (the type size is <literal>\Large</literal>).  The same holds in
+<literal>article</literal> except that there are no chapters in that class so it
+looks like ‘<literal>2 <replaceable>title</replaceable></literal>’.
+</para>
+<para>The <literal>*</literal> form shows <replaceable>title</replaceable>.
+But it does not show the section number, does not increment the
+<literal>section</literal> counter, produces no table of contents entry, and does
+not affect the running header.  (If you use the page style
+<literal>headings</literal> in a two-sided document then the header will be from the
+prior section.)
+</para>
+<para>The optional argument <replaceable>toc-title</replaceable> will appear as the section title
+in the table of contents (see <link linkend="Table-of-contents-etc_002e">Table of contents etc.</link>) and in
+running headers (see <link linkend="Page-styles">Page styles</link>).  If it is not present then
+<replaceable>title</replaceable> will be there.  This shows the full name in the title of the
+section,
+</para>
+<screen>\section[Elizabeth~II]{Elizabeth the Second,
+  by the Grace of God of the United Kingdom,
+  Canada and Her other Realms and Territories Queen,
+  Head of the Commonwealth, Defender of the Faith.}
+</screen>
+<para>but only ‘<literal>Elizabeth II</literal>’ on the contents page and in the headers.
+This has a line break in <replaceable>title</replaceable> but that does not work with headers
+so it is omitted from the contents and headers.
+</para>
+<screen>\section[Truth is, I cheated; my life story]{Truth is,
+  I cheated\\my life story}
+</screen>
+<para>For determining which sectional units are numbered and which appear in
+the table of contents, the level number of a section is 1
+(see <link linkend="Sectioning_002fsecnumdepth">Sectioning/secnumdepth</link> and see <link linkend="Sectioning_002ftocdepth">Sectioning/tocdepth</link>).
+</para>
+<indexterm role="cp"><primary>package, <literal>indentfirst</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>indentfirst</literal> package</primary></indexterm>
+
+<para>The paragraph that follows the section title is not indented, as is a
+standard typographical practice.  One way to get an indent is to use the
+package <filename>indentfirst</filename>.
+</para>
+<indexterm role="cp"><primary>package, <literal>titlesec</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>titlesec</literal> package</primary></indexterm>
+
+<para>In general, to change the behavior of the <literal>\section</literal> command, there
+are a number of options.  One is the <literal>\@startsection</literal> command
+(see <link linkend="_005c_0040startsection">\@startsection</link>).  There are also many packages on CTAN that
+address this, including <filename>titlesec</filename>.  See the documentation but the
+example below gives a sense of what they can do.
+</para>
+<!-- credit: egreg https://groups.google.com/forum/#!topic/comp.text.tex/tvc8oM5P4y4 -->
+<screen>\usepackage{titlesec}   % in preamble
+\titleformat{\section}
+  {\normalfont\Large\bfseries}  % format of title
+  {\makebox[1pc][r]{\thesection\hspace{1pc}}} % label
+  {0pt}                   % length of separation between label and title
+  {}                      % before-code hook
+\titlespacing*{\section}
+  {-1pc}{18pt}{10pt}[10pc]
+</screen>
+<para>That puts the section number in the margin.
+</para>
+
+</sect1>
+<sect1 label="6.4" id="_005csubsection">
+<title><literal>\subsection</literal></title>
+
+<indexterm role="fn"><primary>\subsection</primary></indexterm>
+<indexterm role="cp"><primary>subsection</primary></indexterm>
+
+<para>Synopsis, one of:
+</para>
+<screen>\subsection{<replaceable>title</replaceable>}
+\subsection*{<replaceable>title</replaceable>}
+\subsection[<replaceable>toc-title</replaceable>]{<replaceable>title</replaceable>}
+</screen>
+<para>Start a subsection.  The standard &latex; classes <literal>article</literal>,
+<literal>book</literal>, and <literal>report</literal> all have this command.
+</para>
+<para>This produces a subsection.
+</para>
+<screen>We will show that there are more functions than Turing machines and that
+therefore some functions have no associated machine.
+
+\subsection{Cardinality} We will begin with two paradoxes that
+dramatize the challenge to our intuition posed by comparing the sizes of
+infinite sets.
+</screen>
+<para>For the standard &latex; classes <literal>book</literal> and <literal>report</literal> the
+default output is like ‘<literal>1.2.3 <replaceable>title</replaceable></literal>’ (for chapter 1,
+section 2, subsection 3), alone on its line and flush left, in
+boldface and a larger type (the type size is <literal>\large</literal>).  The same
+holds in <literal>article</literal> except that there are no chapters in that class
+so it looks like ‘<literal>2.3 <replaceable>title</replaceable></literal>’.
+</para>
+<para>The <literal>*</literal> form shows <replaceable>title</replaceable>.
+But it does not show the section number, does not increment the
+<literal>section</literal> counter, and produces no table of contents entry.
+</para>
+<para>The optional argument <replaceable>toc-title</replaceable> will appear as the section title
+in the table of contents (see <link linkend="Table-of-contents-etc_002e">Table of contents etc.</link>).  If it is
+not present then <replaceable>title</replaceable> will be there.  This shows the full name in
+the title of the section,
+</para>
+<screen>\subsection[$\alpha,\beta,\gamma$ paper]{\textit{The Origin of
+  Chemical Elements} by R.A.~Alpher, H.~Bethe, and G.~Gamow}
+</screen>
+<para>but only ‘<literal>&#x03B1;,&#x03B2;,&#x03B3;
+paper</literal>’ on the contents page.
+</para>
+<para>For determining which sectional units are numbered and which appear in
+the table of contents, the level number of a subsection is 2
+(see <link linkend="Sectioning_002fsecnumdepth">Sectioning/secnumdepth</link> and see <link linkend="Sectioning_002ftocdepth">Sectioning/tocdepth</link>).
+</para>
+<indexterm role="cp"><primary>package, <literal>indentfirst</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>indentfirst</literal> package</primary></indexterm>
+
+<para>The paragraph that follows the subsection title is not indented, as is a
+standard typographical practice.  One way to get an indent is to use the
+package <filename>indentfirst</filename>.
+</para>
+<indexterm role="cp"><primary>package, <literal>titlesec</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>titlesec</literal> package</primary></indexterm>
+
+<para>There are a number of ways to change the behavior of the
+<literal>\subsection</literal> command.  One is the <literal>\@startsection</literal> command
+(see <link linkend="_005c_0040startsection">\@startsection</link>).  There are also many packages on CTAN that
+address this, including <filename>titlesec</filename>.  See the documentation but the
+example below gives a sense of what they can do.
+</para>
+<screen>\usepackage{titlesec}   % in preamble
+\titleformat{\subsection}[runin]
+  {\normalfont\normalsize\bfseries}  % format of the title
+  {\thesubsection}                   % label
+  {0.6em}                            % space between label and title
+  {}                                 % before-code hook
+</screen>
+<para>That puts the subsection number and <replaceable>title</replaceable> in the first line of
+text.
+</para>
+
+</sect1>
+
+<sect1 label="6.5" id="_005csubsubsection-_0026-_005cparagraph-_0026-_005csubparagraph">
+<title><literal>\subsubsection</literal>, <literal>\paragraph</literal>, <literal>\subparagraph</literal></title>
+
+<indexterm role="fn"><primary>\subsubsection</primary></indexterm>
+<indexterm role="cp"><primary>subsubsection</primary></indexterm>
+<indexterm role="fn"><primary>\paragraph</primary></indexterm>
+<indexterm role="cp"><primary>paragraph</primary></indexterm>
+<indexterm role="fn"><primary>\subparagraph</primary></indexterm>
+<indexterm role="cp"><primary>subparagraph</primary></indexterm>
+
+<para>Synopsis, one of:
+</para>
+<screen>\subsubsection{<replaceable>title</replaceable>}
+\subsubsection*{<replaceable>title</replaceable>}
+\subsubsection[<replaceable>toc-title</replaceable>]{<replaceable>title</replaceable>}
+</screen>
+<para>or one of:
+</para>
+<screen>\paragraph{<replaceable>title</replaceable>}
+\paragraph*{<replaceable>title</replaceable>}
+\paragraph[<replaceable>toc-title</replaceable>]{<replaceable>title</replaceable>}
+</screen>
+<para>or one of:
+</para>
+<screen>\subparagraph{<replaceable>title</replaceable>}
+\subparagraph*{<replaceable>title</replaceable>}
+\subparagraph[<replaceable>toc-title</replaceable>]{<replaceable>title</replaceable>}
+</screen>
+<para>Start a subsubsection, paragraph, or subparagraph.  The standard
+&latex; classes <literal>article</literal>, <literal>book</literal>, and <literal>report</literal> all have
+these commands, although they are not commonly used.
+</para>
+<para>This produces a subsubsection.
+</para>
+<screen>\subsubsection{Piston ring compressors: structural performance}
+Provide exterior/interior wall cladding assemblies
+capable of withstanding the effects of load and stresses from 
+consumer-grade gasoline engine piston rings.
+</screen>
+<para>The default output of each of the three does not change over the
+standard &latex; classes <literal>article</literal>, <literal>book</literal>, and
+<literal>report</literal>.  For <literal>\subsubsection</literal> the <replaceable>title</replaceable> is alone on
+its line, in boldface and normal size type.  For <literal>\paragraph</literal> the
+<replaceable>title</replaceable> is inline with the text, not indented, in boldface and
+normal size type.  For <literal>\subparagraph</literal> the <replaceable>title</replaceable> is inline
+with the text, with a paragraph indent, in boldface and normal size type
+(Because an <literal>article</literal> has no chapters its subsubsections are
+numbered and so it looks like ‘<literal>1.2.3 <replaceable>title</replaceable></literal>’, for
+section 1, subsection 2, and subsubsection 3.  The other
+two divisions are not numbered.)
+</para>
+<para>The <literal>*</literal> form shows <replaceable>title</replaceable>.  But it does not increment the
+associated counter and produces no table of contents entry (and does not
+show the number for <literal>\subsubsection</literal>).
+</para>
+<para>The optional argument <replaceable>toc-title</replaceable> will appear as the division title
+in the table of contents (see <link linkend="Table-of-contents-etc_002e">Table of contents etc.</link>).  If it is
+not present then <replaceable>title</replaceable> will be there.
+</para>
+<para>For determining which sectional units are numbered and which appear in
+the table of contents, the level number of a subsubsection is 3, of
+a paragraph is 4, and of a subparagraph is 5
+(see <link linkend="Sectioning_002fsecnumdepth">Sectioning/secnumdepth</link> and see <link linkend="Sectioning_002ftocdepth">Sectioning/tocdepth</link>).
+</para>
+<indexterm role="cp"><primary>package, <literal>indentfirst</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>indentfirst</literal> package</primary></indexterm>
+
+<para>The paragraph that follows the subsubsection title is not indented, as is a
+standard typographical practice.  One way to get an indent is to use the
+package <filename>indentfirst</filename>.
+</para>
+<indexterm role="cp"><primary>package, <literal>titlesec</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>titlesec</literal> package</primary></indexterm>
+
+<para>There are a number of ways to change the behavior of the these commands.
+One is the <literal>\@startsection</literal> command (see <link linkend="_005c_0040startsection">\@startsection</link>).
+There are also many packages on CTAN that address this, including
+<filename>titlesec</filename>.  See the documentation on CTAN.
+</para>
+
+</sect1>
+
+<sect1 label="6.6" id="_005cappendix">
+<title><literal>\appendix</literal></title>
+
 <indexterm role="fn"><primary>\appendix</primary></indexterm>
-<indexterm role="cp"><primary>appendix, creating</primary></indexterm>
-<para>The <literal>\appendix</literal> command changes the way following sectional units
-are numbered.  The <literal>\appendix</literal> command itself generates no text
-and does not affect the numbering of parts.  The normal use of this
-command is something like
+<indexterm role="cp"><primary>appendix</primary></indexterm>
+<indexterm role="cp"><primary>appendices</primary></indexterm>
+
+<para>Synopsis:
 </para>
-<screen>\chapter{A Chapter}
-…
+<screen>\appendix
+</screen>
+<para>This does not directly produce any output.  But in a book or report it
+declares that subsequent <literal>\chapter</literal> commands start an appendix.  In
+an article it does the same, for <literal>\section</literal> commands.  It also
+resets the <literal>chapter</literal> and <literal>section</literal> counters to 0 in a
+book or report, and in an article resets the <literal>section</literal> and
+<literal>subsection</literal> counters.
+</para>
+<para>In this book
+</para>
+<screen>\chapter{One}  ...
+\chapter{Two}  ...
+ ...
 \appendix
-\chapter{The First Appendix}
+\chapter{Three}  ...
+\chapter{Four}  ...
 </screen>
-<indexterm role="fn"><primary>secnumdepth counter</primary></indexterm>
-<indexterm role="cp"><primary>section numbers, printing</primary></indexterm>
-<anchor id="Sectioning_002fsecnumdepth"/><para>The <literal>secnumdepth</literal> counter controls printing of section numbers.
-The setting
+<para>the first two will generate output numbered ‘<literal>Chapter 1</literal>’ and
+‘<literal>Chapter 2</literal>’.  After the <literal>\appendix</literal> the numbering will be
+‘<literal>Appendix A</literal>’ and ‘<literal>Appendix B</literal>’.  See <link linkend="Larger-book-template">Larger book template</link>
+for another example.
 </para>
-<screen>\setcounter{secnumdepth}{<replaceable>level</replaceable>}
+<indexterm role="cp"><primary>package, <literal>appendix</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>appendix</literal> package</primary></indexterm>
+<para>The <filename>appendix</filename> package adds the command
+<literal>\appendixpage</literal> to put a separate ‘<literal>Appendices</literal>’ in the document
+body before the first appendix, and the command <literal>\addappheadtotoc</literal>
+to do the same in the table of contents.  You can reset the name
+‘<literal>Appendix</literal>’ with a command like
+<literal>\renewcommand{\appendixname}{Specification}</literal>, as well as a
+number of other features.  See the documentation on CTAN.
+</para>
+
+</sect1>
+
+<sect1 label="6.7" id="_005cfrontmatter-_0026-_005cmainmatter-_0026-_005cbackmatter">
+<title><literal>\frontmatter</literal>, <literal>\mainmatter</literal>, <literal>\backmatter</literal></title>
+
+<indexterm role="fn"><primary>\frontmatter</primary></indexterm>
+<indexterm role="cp"><primary>book, front matter</primary></indexterm>
+<indexterm role="fn"><primary>\mainmatter</primary></indexterm>
+<indexterm role="cp"><primary>book, main matter</primary></indexterm>
+<indexterm role="fn"><primary>\backmatter</primary></indexterm>
+<indexterm role="cp"><primary>book, back matter</primary></indexterm>
+<indexterm role="cp"><primary>book, end matter</primary></indexterm>
+
+<para>Synopsis, one of:
+</para>
+<screen>\frontmatter
+\mainmatter
+\backmatter
 </screen>
-<para>suppresses heading numbers at any depth <inlineequation><mathphrase>> <replaceable>level</replaceable></mathphrase></inlineequation>, where
-<literal>chapter</literal> is level zero.  The default <literal>secnumdepth</literal> is 3 in
-&latex;’s <filename>article</filename> class and 2 in the <filename>book</filename> and
-<filename>report</filename> classes.  (See <link linkend="_005csetcounter">\setcounter</link>.)
+<para>Format a <literal>book</literal> class document differently according to which part
+of the document is being produced.  All three commands are optional.
 </para>
+<para>Traditionally, a book’s front matter contains such things as the title
+page, an abstract, a table of contents, a preface, a list of notations,
+a list of figures, and a list of tables.  (Some of these front matter
+pages, such as the title page, are traditionally not numbered.)  The
+back matter may contain such things as a glossary, notes, a
+bibliography, and an index.
+</para>
+<para>The <literal>\frontmatter</literal> declaration makes the pages numbered in
+lowercase roman, and makes chapters not numbered, although each
+chapter’s title appears in the table of contents; if you use other
+sectioning commands here, use the <literal>*</literal>-version (see <link linkend="Sectioning">Sectioning</link>).
+The <literal>\mainmatter</literal> changes the behavior back to the expected
+version, and resets the page number.  The <literal>\backmatter</literal> leaves the
+page numbering alone but switches the chapters back to being not
+numbered.  See <link linkend="Larger-book-template">Larger book template</link> for an example using the three.
+</para>
 
-
-<sect1 label="6.1" id="_005c_0040startsection">
+</sect1>
+<sect1 label="6.8" id="_005c_0040startsection">
 <title><literal>\@startsection</literal></title>
 
 <indexterm role="fn"><primary>\@startsection</primary></indexterm>
@@ -2430,10 +3052,24 @@
 <!-- xx define, and make a cross reference to, secdef. -->
 </para>
 <para>Technically, <literal>\@startsection</literal> has the form
-</para><screen>\@startsection{<replaceable>name</replaceable>}{<replaceable>level</replaceable>}{<replaceable>indent</replaceable>}{<replaceable>beforeskip</replaceable>}{<replaceable>afterskip</replaceable>}{<replaceable>style</replaceable>}*[<replaceable>toctitle</replaceable>]{<replaceable>title</replaceable>}
-</screen><para>(the star <literal>*</literal> is optional), so that issuing
-</para><screen>\renewcommand{\section}{\@startsection{<replaceable>name</replaceable>}{<replaceable>level</replaceable>}{<replaceable>indent</replaceable>}{<replaceable>beforeskip</replaceable>}{<replaceable>afterskip</replaceable>}{<replaceable>style</replaceable>}}
-</screen><para>redefines <literal>\section</literal> to have the form
+</para>
+<screen>\@startsection{<replaceable>name</replaceable>}
+  {<replaceable>level</replaceable>}
+  {<replaceable>indent</replaceable>}
+  {<replaceable>beforeskip</replaceable>}
+  {<replaceable>afterskip</replaceable>}
+  {<replaceable>style</replaceable>}*[<replaceable>toctitle</replaceable>]{<replaceable>title</replaceable>}
+</screen>
+<para>so that issuing
+</para>
+<screen>\renewcommand{\section}{\@startsection{<replaceable>name</replaceable>}
+  {<replaceable>level</replaceable>}
+  {<replaceable>indent</replaceable>}
+  {<replaceable>beforeskip</replaceable>}
+  {<replaceable>afterskip</replaceable>}
+  {<replaceable>style</replaceable>}}
+</screen>
+<para>redefines <literal>\section</literal> to have the form
 <literal>\section*[<replaceable>toctitle</replaceable>]{<replaceable>title</replaceable>}</literal> (here too, the
 star <literal>*</literal> is optional).  See <link linkend="Sectioning">Sectioning</link>.  This implies that
 when you write a command like <literal>\renewcommand{section}{...}</literal>,
@@ -2442,55 +3078,48 @@
 </para>
 <variablelist>
 <varlistentry><term><replaceable>name</replaceable>
-</term><listitem><anchor id="_005c_0040startsection_002fname"/><para>Name of the counter used to number the
-sectioning header.  This counter must be defined separately.  Most
-commonly this is either <literal>section</literal>, <literal>subsection</literal>, or
-<literal>paragraph</literal>.  Although in those three cases the counter name is the
-same as the sectioning command itself, using the same name is not
-required.
+</term><listitem><anchor id="startsection-name"/><anchor id="_005c_0040startsection_002fname"/><para>Name of the counter used to number the sectioning header.  This counter
+must be defined separately.  Most commonly this is either
+<literal>section</literal>, <literal>subsection</literal>, or <literal>paragraph</literal>.  Although in
+those cases the counter name is the same as the sectioning command
+itself, you don’t have to use the same name.
 </para>
 <para>Then <literal>\the</literal><replaceable>name</replaceable> displays the title number and
 <literal>\</literal><replaceable>name</replaceable><literal>mark</literal> is for the page headers.  See the third
 example below.
 </para>
 </listitem></varlistentry><varlistentry><term><replaceable>level</replaceable>
-</term><listitem><anchor id="_005c_0040startsection_002flevel"/><para>An integer giving the depth of the
-sectioning command: 0 for <literal>chapter</literal> (only applies to the standard
-<literal>book</literal> and <literal>report</literal> classes), 1 for <literal>section</literal>, 2 for
-<literal>subsection</literal>, 3 for <literal>subsubsection</literal>, 4 for <literal>paragraph</literal>,
-and 5 for <literal>subparagraph</literal>.  In the <literal>book</literal> and <literal>report</literal>
-classes <literal>part</literal> has level -1, while in the <literal>article</literal> class
-<literal>part</literal> has level 0.
+</term><listitem><anchor id="startsection-level"/><anchor id="_005c_0040startsection_002flevel"/><para>An integer giving the depth of the sectioning command.
+See <link linkend="Sectioning">Sectioning</link> for the list of standard level numbers.
 </para>
-<para>If <replaceable>level</replaceable> is less than or equal to the value of <literal>secnumdepth</literal>
-then the titles for this sectioning command will be numbered.  For
-instance, in an <literal>article</literal>, if <literal>secnumdepth</literal> is 1 then a
-<literal>\section{Introduction}</literal> command will produce output like “1
+<para>If <replaceable>level</replaceable> is less than or equal to the value of the counter
+<literal>secnumdepth</literal> then titles for this sectioning command will be
+numbered (see <link linkend="Sectioning_002fsecnumdepth">Sectioning/secnumdepth</link>).  For instance, if
+<literal>secnumdepth</literal> is 1 in an <literal>article</literal> then the command
+<literal>\section{Introduction}</literal> will produce output like “1
 Introduction” while <literal>\subsection{Discussion}</literal> will produce
 output like “Discussion”, without the number prefix.
-See <link linkend="Sectioning_002fsecnumdepth">Sectioning/secnumdepth</link>.
 </para>
-<para>If <replaceable>level</replaceable> is less than or equal to the value of <replaceable>tocdepth</replaceable> then
-the table of contents will have an entry for this sectioning unit.
-For instance, in an <literal>article</literal>, if <replaceable>tocdepth</replaceable> is 1 then the table of
-contents will list sections but not subsections.
-<!-- xx add, and cross reference to, tocdepth -->
+<para>If <replaceable>level</replaceable> is less than or equal to the value of the counter
+<replaceable>tocdepth</replaceable> then the table of contents will have an entry for this
+sectioning unit (see <link linkend="Sectioning_002ftocdepth">Sectioning/tocdepth</link>).  For instance, in an
+<literal>article</literal>, if <replaceable>tocdepth</replaceable> is 1 then the table of contents will
+list sections but not subsections.
 </para>
 </listitem></varlistentry><varlistentry><term><replaceable>indent</replaceable>
-</term><listitem><anchor id="_005c_0040startsection_002findent"/><para>A length giving the indentation of all
-of the title lines with respect to the left margin.  To have the title
-flush with the margin use <literal>0pt</literal>.  A negative indentation such as
-<literal>-\parindent</literal> will move the title into the left margin.
+</term><listitem><anchor id="startsection-indent"/><anchor id="_005c_0040startsection_002findent"/><para>A length giving the indentation of all of the title lines with respect
+to the left margin.  To have the title flush with the margin use
+<literal>0pt</literal>.  A negative indentation such as <literal>-\parindent</literal> will move
+the title into the left margin.
 </para>
 </listitem></varlistentry><varlistentry><term><replaceable>beforeskip</replaceable>
-</term><listitem><anchor id="_005c_0040startsection_002fbeforeskip"/><para>The absolute value of this length is
-the amount of vertical space that is inserted before this sectioning
-unit’s title.  This space will be discarded if the sectioning unit
-happens to start at the top of a fresh page.  If this number is negative
-then the first paragraph following the header is not indented, if it is
-non-negative then the first paragraph is indented.  (Note that the
-negative of <literal>1pt plus 2pt minus 3pt</literal> is <literal>-1pt plus -2pt minus
--3pt</literal>.)
+</term><listitem><anchor id="startsection-beforeskip"/><anchor id="_005c_0040startsection_002fbeforeskip"/><para>The absolute value of this length is the amount of vertical space that
+is inserted before this sectioning unit’s title.  This space will be
+discarded if the sectioning unit happens to start at the top of a fresh
+page.  If this number is negative then the first paragraph following the
+header is not indented, if it is non-negative then the first paragraph
+is indented.  (Note that the negative of <literal>1pt plus 2pt minus 3pt</literal>
+is <literal>-1pt plus -2pt minus -3pt</literal>.)
 </para>
 <para>For example, if <replaceable>beforeskip</replaceable> is <literal>-3.5ex plus -1ex minus -0.2ex</literal>
 then to start the new sectioning unit, &latex; will add about 3.5 times
@@ -2510,14 +3139,13 @@
 page.)
 </para>
 </listitem></varlistentry><varlistentry><term><replaceable>afterskip</replaceable>
-</term><listitem><anchor id="_005c_0040startsection_002fafterskip"/><para>This is a length.  If <replaceable>afterskip</replaceable>
-is non-negative then this is the vertical space inserted after the
-sectioning unit’s title header.  If it is negative then the title header
-becomes a run-in header, so that it becomes part of the next paragraph.
-In this case the absolute value of the length gives the horizontal space
-between the end of the title and the beginning of the following
-paragraph.  (Note that the negative of <literal>1pt plus 2pt minus 3pt</literal> is
-<literal>-1pt plus -2pt minus -3pt</literal>.)
+</term><listitem><anchor id="startsection-afterskip"/><anchor id="_005c_0040startsection_002fafterskip"/><para>This is a length.  If <replaceable>afterskip</replaceable> is non-negative then this is the
+vertical space inserted after the sectioning unit’s title header.  If it
+is negative then the title header becomes a run-in header, so that it
+becomes part of the next paragraph.  In this case the absolute value of
+the length gives the horizontal space between the end of the title and
+the beginning of the following paragraph.  (Note that the negative of
+<literal>1pt plus 2pt minus 3pt</literal> is <literal>-1pt plus -2pt minus -3pt</literal>.)
 </para>
 <para>As with <replaceable>beforeskip</replaceable>, using a rubber length, with <literal>plus</literal> and
 <literal>minus</literal> components, is good practice here since it gives &latex;
@@ -2534,45 +3162,36 @@
 <literal>afterskip</literal> to cancel part of the <literal>\parskip</literal>.)
 </para>
 </listitem></varlistentry><varlistentry><term><replaceable>style</replaceable>
-</term><listitem><anchor id="_005c_0040startsection_002fstyle"/><para>Controls the styling of the title.  See
-the examples below.  Typical commands to use here are <literal>\centering</literal>,
-<literal>\raggedright</literal>, <literal>\normalfont</literal>, <literal>\hrule</literal>, or
-<literal>\newpage</literal>.  The last command in <replaceable>style</replaceable> may be one such as
-<literal>\MakeUppercase</literal> or <literal>\fbox</literal> that takes one argument. The
+</term><listitem><anchor id="startsection-style"/><anchor id="_005c_0040startsection_002fstyle"/><para>Controls the styling of the title.  See the examples below.  Typical
+commands to use here are <literal>\centering</literal>, <literal>\raggedright</literal>,
+<literal>\normalfont</literal>, <literal>\hrule</literal>, or <literal>\newpage</literal>.  The last command
+in <replaceable>style</replaceable> may be one that takes one argument, such as
+<literal>\MakeUppercase</literal> or <literal>\fbox</literal> that takes one argument.  The
 section title will be supplied as the argument to this command. For
 instance, setting <replaceable>style</replaceable> to <literal>\bfseries\MakeUppercase</literal> would
-produce titles that are bold and upper case.
+produce titles that are bold and uppercase.
 </para></listitem></varlistentry></variablelist>
 <para>These are &latex;’s defaults for the first three sectioning units that
 are defined with <literal>\@startsection</literal>, for the <filename>article</filename>,
-<filename>book</filename>, and <filename>report</filename> classes.
+<filename>book</filename>, and <filename>report</filename> classes.  For section, the <replaceable>level</replaceable> is
+1, the <replaceable>indent</replaceable> is 0pt, the <replaceable>beforeskip</replaceable> is <literal>-3.5ex
+plus -1ex minus -0.2ex</literal>, the <replaceable>afterskip</replaceable> is <literal>2.3ex plus 0.2ex</literal>,
+and the <replaceable>style</replaceable> is <literal>\normalfont\Large\bfseries</literal>.  For
+subsection, the <replaceable>level</replaceable> is 2, the <replaceable>indent</replaceable> is 0pt, the
+<replaceable>beforeskip</replaceable> is <literal>-3.25ex plus -1ex minus -0.2ex</literal>, the
+<replaceable>afterskip</replaceable> is <literal>1.5ex plus 0.2ex</literal>, and the <replaceable>style</replaceable> is
+<literal>\normalfont\large\bfseries</literal>.  For subsubsection, the <replaceable>level</replaceable>
+is 3, the <replaceable>indent</replaceable> is 0pt, the <replaceable>beforeskip</replaceable> is
+<literal>-3.25ex plus -1ex minus -0.2ex</literal>, the <replaceable>afterskip</replaceable> is
+<literal>1.5ex plus 0.2ex</literal>, and the <replaceable>style</replaceable> is
+<literal>\normalfont\normalsize\bfseries</literal>.
 </para>
-<informaltable><tgroup cols="4"><colspec colwidth="10*"></colspec><colspec colwidth="30*"></colspec><colspec colwidth="30*"></colspec><colspec colwidth="30*"></colspec><thead><row><entry></entry><entry><para><literal>section</literal>  </para></entry><entry><para><literal>subsection</literal>  </para></entry><entry><para><literal>subsubsection</literal>
-</para></entry></row></thead><tbody><row><entry><para><link linkend="_005c_0040startsection_002fname"><replaceable>name</replaceable></link>
-</para></entry><entry><para>section          </para></entry><entry><para>subsection          </para></entry><entry><para>subsubsection
-</para></entry></row><row><entry><para><link linkend="_005c_0040startsection_002flevel"><replaceable>level</replaceable></link>
-</para></entry><entry><para>1          </para></entry><entry><para>2          </para></entry><entry><para>3
-</para></entry></row><row><entry><para><link linkend="_005c_0040startsection_002findent"><replaceable>indent</replaceable></link>
-</para></entry><entry><para><literal>0pt</literal>          </para></entry><entry><para><literal>0pt</literal>          </para></entry><entry><para><literal>0pt</literal>
-</para></entry></row><row><entry><para><link linkend="_005c_0040startsection_002fbeforeskip"><replaceable>beforeskip</replaceable></link>
-</para></entry><entry><para><literal>-3.5ex plus -1ex minus -0.2ex</literal>
-</para></entry><entry><para><literal>-3.25ex plus -1ex minus -0.2ex</literal>
-</para></entry><entry><para><literal>-3.25ex plus -1ex minus -0.2ex</literal>
-</para></entry></row><row><entry><para><link linkend="_005c_0040startsection_002fafterskip"><replaceable>afterskip</replaceable></link>
-</para></entry><entry><para><literal>2.3ex plus 0.2ex</literal>
-</para></entry><entry><para><literal>1.5ex plus 0.2ex</literal>
-</para></entry><entry><para><literal>1.5ex plus 0.2ex</literal>
-</para></entry></row><row><entry><para><link linkend="_005c_0040startsection_002fstyle"><replaceable>style</replaceable></link>
-</para></entry><entry><para><literal>\normalfont\Large\bfseries</literal>
-</para></entry><entry><para><literal>\normalfont\large\bfseries</literal>
-</para></entry><entry><para><literal>\normalfont\normalsize\bfseries</literal>
-</para></entry></row></tbody></tgroup></informaltable>
 <para>Here are examples.  They go either in a package or class file or in the
 preamble of a &latex; document.  If you put them in the preamble they
 must go between a <literal>\makeatletter</literal> command and a
 <literal>\makeatother</literal>.  (Probably the error message <literal>You can't use
 `\spacefactor' in vertical mode.</literal>  means that you forgot this.)
-See <link linkend="_005cmakeatletter-and-_005cmakeatother">\makeatletter and \makeatother</link>.
+See <link linkend="_005cmakeatletter-_0026-_005cmakeatother">\makeatletter & \makeatother</link>.
 </para>
 <para>This will put section titles in large boldface type, centered.  It says
 <literal>\renewcommand</literal> because &latex;’s standard classes have already
@@ -2600,7 +3219,9 @@
     {\scshape}% <link linkend="_005c_0040startsection_002fstyle"><replaceable>style</replaceable></link>
   }
 </screen>
-<para>The prior examples redefined existing sectional unit title commands.  This defines a new one, illustrating the needed counter and macros to display that counter.
+<para>The prior examples redefined existing sectional unit title commands.
+This defines a new one, illustrating the needed counter and macros to
+display that counter.
 </para>
 <!-- From https://groups.google.com/forum/#!searchin/comp.text.tex/startsection%7Csort:relevance/comp.text.tex/sB-nTS-oL08/ZZeKYdG0llMJ -->
 <screen>\setcounter{secnumdepth}{6}% show counters this far down
@@ -2625,39 +3246,49 @@
 
 <indexterm role="cp"><primary>cross references</primary></indexterm>
 
-<para>One reason for numbering things such as figures and equations is to
-refer the reader to them, as in “See Figure~3 for more details.”
-</para>
 <indexterm role="cp"><primary>label</primary></indexterm>
-<para>Including the figure number in the source is poor practice since if that
-number changes as the document evolves then you must remember to update
-this reference by hand.  Instead, &latex; has you write a <firstterm>label</firstterm>
-like <literal>\label{eq:GreensThm}</literal> and refer to it with <literal>See
-equation~\ref{eq:GreensThm}</literal>.
+<para>We often want something like ‘<literal>See Theorem~31</literal>’.  But by-hand typing
+the 31 is poor practice.  Instead you should write a <firstterm>label</firstterm> such as
+<literal>\label{eq:GreensThm}</literal> and then <firstterm>reference</firstterm> it, as with
+<literal>See equation~\ref{eq:GreensThm}</literal>.  &latex; will automatically
+work out the number, put it into the output, and will change that number
+later if needed.
 </para>
-<para>&latex; writes the information from the labels to a file with the same
-name as the file containing the <literal>\label{...}</literal> but with an
-<filename>.aux</filename> extension.  (The information has the format
-<literal>\newlabel{<replaceable>label</replaceable>}{{<replaceable>currentlabel</replaceable>}{<replaceable>pagenumber</replaceable>}}</literal>
-where <replaceable>currentlabel</replaceable> is the current value of the macro
-<literal>\@currentlabel</literal> that is usually updated whenever you call
-<literal>\refstepcounter{<replaceable>counter</replaceable>}</literal>.)
+<screen>We will see this with Theorem~\ref{th:GreensThm}. % forward reference
+...
+\begin{theorem} \label{th:GreensThm}
+  ...
+\end{theorem}
+...
+See Theorem~\ref{th:GreensThm} on page~\pageref{th:GreensThm}.
+</screen>
+<para>&latex; tracks cross reference information in a file having the
+extension <filename>.aux</filename> and with the same base name as the file containing
+the <literal>\label</literal>.  So if <literal>\label</literal> is in <filename>calculus.tex</filename> then
+the information is in <filename>calculus.aux</filename>.  &latex; puts the
+information in that file every time it runs across a <literal>\label</literal>.
 </para>
 <indexterm role="cp"><primary>forward reference</primary></indexterm>
 <indexterm role="cp"><primary>reference, forward</primary></indexterm>
-<para>The most common side effect of the prior paragraph happens when your
-document has a <firstterm>forward reference</firstterm>, a <literal>\ref{<replaceable>key</replaceable>}</literal> that
-appears earlier than the associated <literal>\label{<replaceable>key</replaceable>}</literal>; see the
-example in the <literal>\pageref{...}</literal> description.  &latex; gets the
-information for references from the <filename>.aux</filename> file.  If this is the
-first time you are compiling the document then you will get a message
-<literal>LaTeX Warning: Label(s) may have changed. Rerun to get
-cross references right.</literal> and in the output the reference will appear as
-two question marks ‘<literal>??</literal>’, in boldface.  Or, if you change some
-things so the references change then you get the same warning and the
-output contains the old reference information.  The solution in either
-case is just to compile the document a second time.
+<para>The behavior described in the prior paragraph results in a quirk that
+happens when your document has a <firstterm>forward reference</firstterm>, a <literal>\ref</literal>
+that appears before the associated <literal>\label</literal>.  If this is the first
+time that you are compiling the document then you will get ‘<literal>LaTeX
+Warning: Label(s) may have changed. Rerun to get cross references right</literal>’
+and in the output the forward reference will appear as two question
+marks ‘<literal>??</literal>’, in boldface.  A similar thing happens if you
+change some things so the references changes; you get the same warning
+and the output contains the old reference information.  In both cases,
+resolve this by compiling the document a second time.
 </para>
+<indexterm role="cp"><primary>package, <literal>cleveref</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>cleveref</literal> package</primary></indexterm>
+<para>The <literal>cleveref</literal> package enhances &latex;’s
+cross referencing features.  You can arrange that if you enter
+<literal>\begin{thm}\label{th:Nerode}...\end{thm}</literal> then
+<literal>\cref{th:Nerode}</literal> will output ‘<literal>Theorem 3.21</literal>’, without you
+having to enter the “Theorem.”
+</para>
 
 
 <sect1 label="7.1" id="_005clabel">
@@ -2682,28 +3313,37 @@
 distinguished, as usual.
 </para>
 <para>A common convention is to use labels consisting of a prefix and a suffix
-separated by a colon or period.  This helps to avoid accidentally
-creating two labels with the same name, and makes your source more
-readable.  Some commonly-used prefixes:
+separated by a colon or period.  Thus, <literal>\label{fig:Post}</literal> is a
+label for a figure with a portrait of Emil Post.  This helps to avoid
+accidentally creating two labels with the same name, and makes your
+source more readable.  Some commonly-used prefixes:
 </para>
 <variablelist><varlistentry><term><literal>ch</literal>
 </term><listitem><para>for chapters
-</para></listitem></varlistentry><varlistentry><term><literal>sec</literal>
+</para>
+</listitem></varlistentry><varlistentry><term><literal>sec</literal>
+</term><term><literal>subsec</literal>
 </term><listitem><para>for lower-level sectioning commands
-</para></listitem></varlistentry><varlistentry><term><literal>fig</literal>
+</para>
+</listitem></varlistentry><varlistentry><term><literal>fig</literal>
 </term><listitem><para>for figures
-</para></listitem></varlistentry><varlistentry><term><literal>tab</literal>
+</para>
+</listitem></varlistentry><varlistentry><term><literal>tab</literal>
 </term><listitem><para>for tables
-</para></listitem></varlistentry><varlistentry><term><literal>eq</literal>
+</para>
+</listitem></varlistentry><varlistentry><term><literal>eq</literal>
 </term><listitem><para>for equations
 </para></listitem></varlistentry></variablelist>
-<para>Thus, <literal>\label{fig:Euler}</literal> is a label for a figure with a portrait
-of the great man.
+<para>In the auxiliary file the reference information is kept as the text of
+a command of the form
+<literal>\newlabel{<replaceable>label</replaceable>}{{<replaceable>currentlabel</replaceable>}{<replaceable>pagenumber</replaceable>}}</literal>.
+Here <replaceable>currentlabel</replaceable> is the current value of the macro
+<literal>\@currentlabel</literal> that is usually updated whenever you call
+<literal>\refstepcounter{<replaceable>counter</replaceable>}</literal>.
 </para>
-<para>In this example below the key <literal>sec:test</literal> will get the number of the
-current section and the key <literal>fig:test</literal> will get the number of the
-figure.  (Incidentally, put labels after captions in figures and
-tables.)
+<para>Below, the key <literal>sec:test</literal> will get the number of the current
+section and the key <literal>fig:test</literal> will get the number of the figure.
+(Incidentally, put labels after captions in figures and tables.)
 </para>
 <screen>\section{section name}
 \label{sec:test}
@@ -2718,7 +3358,7 @@
 
 </sect1>
 <sect1 label="7.2" id="_005cpageref">
-<title><literal>\pageref{<replaceable>key</replaceable>}</literal></title>
+<title><literal>\pageref</literal></title>
 
 <indexterm role="fn"><primary>\pageref</primary></indexterm>
 <indexterm role="cp"><primary>cross referencing with page number</primary></indexterm>
@@ -2731,11 +3371,15 @@
 <para>Produce the page number of the place in the text where the corresponding
 <literal>\label</literal>{<replaceable>key</replaceable>} command appears.
 </para>
-<para>In this example the <literal>\label{eq:main}</literal> is used both for the
-formula number and for the page number.  (Note that the two references
-are forward references, so this document would need to be compiled twice
-to resolve those.)
+<para>If there is no <literal>\label{<replaceable>key</replaceable>}</literal> then you get something like
+‘<literal>LaTeX Warning: Reference `th:GrensThm' on page 1 undefined on
+input line 11.</literal>’
 </para>
+<para>Below, the <literal>\label{eq:main}</literal> is used both for the formula number
+and for the page number.  (Note that the two references are forward
+references so this document would need to be compiled twice to resolve
+those.)
+</para>
 <screen>The main result is formula~\ref{eq:main} on page~\pageref{eq:main}.
   ...
 \begin{equation} \label{eq:main}
@@ -2745,7 +3389,7 @@
 
 </sect1>
 <sect1 label="7.3" id="_005cref">
-<title><literal>\ref{<replaceable>key</replaceable>}</literal></title>
+<title><literal>\ref</literal></title>
 
 <indexterm role="fn"><primary>\ref</primary></indexterm>
 <indexterm role="cp"><primary>cross referencing, symbolic</primary></indexterm>
@@ -2763,10 +3407,14 @@
 <literal>\label</literal> command (see <link linkend="_005clabel">\label</link>).  It does not produce any text,
 such as the word ‘Section’ or ‘Figure’, just the bare number itself.
 </para>
-<para>In this example, the <literal>\ref{popular}</literal> produces ‘<literal>2</literal>’.  Note
-that it is a forward reference since it comes before
-<literal>\label{popular}</literal>.
+<para>If there is no <literal>\label{<replaceable>key</replaceable>}</literal> then you get something like
+‘<literal>LaTeX Warning: Reference `th:GrensThm' on page 1 undefined on
+input line 11.</literal>’
 </para>
+<para>In this example the <literal>\ref{popular}</literal> produces ‘<literal>2</literal>’.  Note that
+it is a forward reference since it comes before <literal>\label{popular}</literal>
+so this document would have to be compiled twice.
+</para>
 <screen>The most widely-used format is item number~\ref{popular}.
 \begin{enumerate}
 \item Plain \TeX
@@ -2774,7 +3422,13 @@
 \item Con\TeX t
 \end{enumerate}
 </screen>
+<indexterm role="cp"><primary>package, <literal>cleveref</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>cleveref</literal> package</primary></indexterm>
 
+<para>The <filename>cleveref</filename> package includes text such as ‘<literal>Theorem</literal>’ in the
+reference.  See the documentation on CTAN.
+</para>
+
 </sect1>
 </chapter>
 <chapter label="8" id="Environments">
@@ -2872,7 +3526,7 @@
   ...
 \end{array}
 </screen>
-<para>or
+<para>or:
 </para>
 <screen>\begin{array}[<replaceable>pos</replaceable>]{<replaceable>cols</replaceable>}
   <replaceable>column 1 entry</replaceable> &<replaceable>column 2 entry</replaceable> ... &<replaceable>column n entry</replaceable> \\
@@ -2881,26 +3535,42 @@
 </screen>
 <para>Produce a mathematical array.  This environment can only be used in math
 mode, and normally appears within a displayed mathematics environment
-such as <literal>equation</literal> (see <link linkend="equation">equation</link>).  Column entries are
-separated by an ampersand (<literal>&</literal>).  Rows are terminated with
-double-backslashes (see <link linkend="_005c_005c">\\</link>).  
+such as <literal>equation</literal> (see <link linkend="equation">equation</link>).  Inside of each row the
+column entries are separated by an ampersand, (<literal>&</literal>).  Rows are
+terminated with double-backslashes (see <link linkend="_005c_005c">\\</link>).
 </para>
+<para>This example shows a three by three array.
+</para>
+<screen>\begin{equation*}
+  \chi(x) =
+  \left|              % vertical bar fence
+    \begin{array}{ccc}
+      x-a  &-b  &-c  \\
+      -d   &x-e &-f  \\
+      -g   &-h  &x-i
+    \end{array}
+ \right|
+\end{equation*}
+</screen>
 <para>The required argument <replaceable>cols</replaceable> describes the number of columns, their
-alignment, and the formatting of the intercolumn regions.  See
-<link linkend="tabular">tabular</link> for the complete description of <replaceable>cols</replaceable>, and of the
+alignment, and the formatting of the intercolumn regions.  For instance,
+<literal>\begin{array}{rcl}...\end{array}</literal> gives three columns: the
+first flush right, the second centered, and the third flush left.  See
+<link linkend="tabular">tabular</link> for the complete description of <replaceable>cols</replaceable> and of the
 other common features of the two environments, including the optional
 <replaceable>pos</replaceable> argument.
 </para>
 <para>There are two ways that <literal>array</literal> diverges from <literal>tabular</literal>.  The
 first is that <literal>array</literal> entries are typeset in math mode, in
-textstyle (except if the <replaceable>cols</replaceable> definition specifies the column with
-<literal>p{...}</literal>, which causes the entry to be typeset in text mode).
-The second is that, instead of <literal>tabular</literal>’s parameter
-<literal>\tabcolsep</literal>, &latex;’s intercolumn space in an <literal>array</literal> is governed
-by
+textstyle (see <link linkend="Modes">Modes</link>) except if the <replaceable>cols</replaceable> definition specifies
+the column with <literal>p{...}</literal>, which causes the entry to be typeset in
+text mode.  The second is that, instead of <literal>tabular</literal>’s parameter
+<literal>\tabcolsep</literal>, &latex;’s intercolumn space in an <literal>array</literal> is
+governed by
 <indexterm role="fn"><primary>\arraycolsep</primary></indexterm>
 <literal>\arraycolsep</literal>, which gives half the width between columns. The
-default for this is ‘<literal>5pt</literal>’.
+default for this is ‘<literal>5pt</literal>’ so that between two columns comes
+10pt of space.
 </para>
 <indexterm role="cp"><primary>package, <literal>amsmath</literal></primary></indexterm>
 <indexterm role="cp"><primary><literal>amsmath</literal> package</primary></indexterm>
@@ -2914,26 +3584,32 @@
 <literal>Vmatrix</literal> for an array surrounded by double vertical
 bars <literal>||...||</literal>, along with a number of other array constructs.
 </para>
-<para>Here is an example of an array:
+<indexterm role="cp"><primary>package, <literal>amsmath</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>amsmath</literal> package</primary></indexterm>
+
+<para>The next example uses the <filename>amsmath</filename> package.
 </para>
-<screen>\begin{equation}
-  \begin{array}{cr}
-    \sqrt{y}  &12.3 \\
-    x^2       &3.4       
-  \end{array}
-\end{equation}
-</screen>
-<para>The next example works if <literal>\usepackage{amsmath}</literal> is in the
-preamble:
-</para>
-<screen>\begin{equation}
-  \begin{vmatrix}{cc}
+<screen>\usepackage{amsmath}  % in preamble
+
+\begin{equation}    
+  \begin{vmatrix}{cc}  % array with vert lines
     a  &b \\
     c  &d       
   \end{vmatrix}=ad-bc
 \end{equation}
 </screen>
+<indexterm role="cp"><primary>package, <literal>array (package)</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>array (package)</literal> package</primary></indexterm>
 
+<indexterm role="cp"><primary>package, <literal>dcolumn</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>dcolumn</literal> package</primary></indexterm>
+
+<para>There are many packages concerning arrays.  The <filename>array</filename> package has
+many useful extensions, including more column types.  The <filename>dcolumn</filename>
+package adds a column type to center on a decimal point.  For both see
+the documentation on CTAN.
+</para>
+
 </sect1>
 <sect1 label="8.3" id="center">
 <title><literal>center</literal></title>
@@ -2946,16 +3622,18 @@
 <para>Synopsis:
 </para>
 <screen>\begin{center}
-  ... text ...
+  <replaceable>line1</replaceable> \\
+  <replaceable>line2</replaceable> \\
+  ...
 \end{center}
 </screen>
 <para>Create a new paragraph consisting of a sequence of lines that are
-centered within the left and right margins on the current page.  Use
-double-backslash to get a line break at a particular spot (see <link linkend="_005c_005c">\\</link>).
+centered within the left and right margins.  Use
+double-backslash, <literal>\\</literal>, to get a line break (see <link linkend="_005c_005c">\\</link>).
 <indexterm role="fn"><primary>\\ (for <literal>center</literal>)</primary></indexterm>
-If some text environment body is too long to fit on a line, &latex;
-will insert line breaks that avoid hyphenation and avoid stretching or
-shrinking any interword space.
+If some text is too long to fit on a line then &latex; will insert line
+breaks that avoid hyphenation and avoid stretching or shrinking any
+interword space.
 </para>
 <para>This environment inserts space above and below the text body.  See
 <link linkend="_005ccentering">\centering</link> to avoid such space, for example inside a <literal>figure</literal>
@@ -2982,8 +3660,12 @@
   I grew up in that belief.  --Richard Burton 
 \end{center}
 </screen>
-<para>A double backslash after the final line is optional.
+<para>A double backslash after the final line is optional.  If present it
+doesn’t add any vertical space.
 </para>
+<para>In a two-column document the text is centered in a column, not in the
+entire page.
+</para>
 
 
 <sect2 label="8.3.1" id="_005ccentering">
@@ -2992,12 +3674,34 @@
 <indexterm role="fn"><primary>\centering</primary></indexterm>
 <indexterm role="cp"><primary>centering text, declaration for</primary></indexterm>
 
-<para>A declaration that causes material in its scope to be centered.  It is
-most often used inside an environment such as <literal>figure</literal>, or in a
-<literal>parbox</literal>.
+
+<para>Synopsis:
 </para>
+<screen>{\centering ... }
+</screen>
+<para>or
+</para>
+<screen>\begin{group}
+  \centering ...
+\end{group}
+</screen>
+<para>Center the material in its scope.  It is most often used inside an
+environment such as <literal>figure</literal>, or in a <literal>parbox</literal>.
+</para>
+<para>This example’s <literal>\centering</literal> declaration causes the graphic to be
+horizontally centered.
+</para>
+<screen>\begin{figure}
+  \centering
+  \includegraphics[width=0.6\textwidth]{ctan_lion.png}
+  \caption{CTAN Lion}  \label{fig:CTANLion}
+\end{figure}
+</screen>
+<para>The scope of this <literal>\centering</literal> ends with the <literal>\end{figure}</literal>.
+</para>
 <para>Unlike the <literal>center</literal> environment, the <literal>\centering</literal> command does
-not add vertical space above and below the text.
+not add vertical space above and below the text.  That’s its advantage
+in the above example; there is not an excess of space.
 </para>
 <para>It also does not start a new paragraph; it simply changes how &latex;
 formats paragraph units.  If <literal>ww {\centering xx \\ yy} zz</literal> is
@@ -3009,19 +3713,8 @@
 paragraph unit.  Thus, if <literal>{\centering xx \\ yy\par} zz</literal> is
 surrounded by blank lines then it makes a new paragraph with two
 centered lines ‘<literal>xx</literal>’ and ‘<literal>yy</literal>’, followed by a new paragraph with
-‘<literal>zz</literal>’ that is formatted as usual.  See also the following example.
+‘<literal>zz</literal>’ that is formatted as usual.
 </para>
-<para>This example’s <literal>\centering</literal> causes the graphic to be horizontally
-centered.  
-</para>
-<screen>\begin{figure}
-  \centering
-  \includegraphics[width=0.6\textwidth]{ctan_lion.png}
-  \caption{CTAN Lion}  \label{fig:CTANLion}
-\end{figure}
-</screen>
-<para>The scope of the <literal>\centering</literal> ends with the <literal>\end{figure}</literal>.
-</para>
 
 </sect2>
 </sect1>
@@ -3037,26 +3730,27 @@
 <para>Synopsis:
 </para>
 <screen>\begin{description}
-\item[<replaceable>label of first item</replaceable>] text of first item
-\item[<replaceable>label of second item</replaceable>] text of second item
-  ...
+  \item[<replaceable>label of first item</replaceable>] <replaceable>text of first item</replaceable>
+  \item[<replaceable>label of second item</replaceable>] <replaceable>text of second item</replaceable>
+   ...
 \end{description}
 </screen>
-<para>Environment to make a labeled list of items.  Each item’s <replaceable>label</replaceable> is
-typeset in bold, and is flush left so that long labels continue into the
+<para>Environment to make a list of labeled items.  Each item’s <replaceable>label</replaceable> is
+typeset in bold and is flush left, so that long labels continue into the
 first line of the item text.  There must be at least one item; having
 none causes the &latex; error ‘<literal>Something's wrong--perhaps a
 missing \item</literal>’.
 </para>
 <para>This example shows the environment used for a sequence of definitions.
-The labels ‘<literal>lama</literal>’ and ‘<literal>llama</literal>’ come out in boldface with their
-left edges aligned on the left margin.
 </para>
 <screen>\begin{definition}
   \item[lama] A priest.
   \item[llama] A beast.
 \end{definition}
 </screen>
+<para>The labels ‘<literal>lama</literal>’ and ‘<literal>llama</literal>’ are output in boldface, with the
+left edge on the left margin.
+</para>
 <indexterm role="fn"><primary>\item</primary></indexterm>
 <para>Start list items with the <literal>\item</literal> command (see <link linkend="_005citem">\item</link>).  Use the
 optional labels, as in <literal>\item[Main point]</literal>, because there is
@@ -3069,10 +3763,10 @@
 change given in argument style (see <link linkend="Font-styles">Font styles</link>) then it will come
 out bold.  For instance, if the label text calls for typewriter with
 <literal>\item[\texttt{label text}]</literal> then it will appear in bold
-typewriter, if that is available. The simplest way to get non-bold
-typewriter is to use declarative style: <literal>\item[{\tt label
-text}]</literal>.  Similarly, get the standard roman font with <literal>\item[{\rm
-label text}]</literal>.
+typewriter, if that is available. The simplest way around this, in this
+example to get non-bold typewriter, is to use declarative style:
+<literal>\item[{\tt label text}]</literal>.  Similarly, get the standard roman
+font with <literal>\item[{\rm label text}]</literal>.
 </para>
 <para>For other major &latex; labelled list environments, see <link linkend="itemize">itemize</link>
 and <link linkend="enumerate">enumerate</link>.  Unlike those environments, nesting
@@ -3102,7 +3796,7 @@
 <para>Synopsis:
 </para>
 <screen>\begin{displaymath}
-<replaceable>math text</replaceable>
+  <replaceable>mathematical text</replaceable>
 \end{displaymath}
 </screen>
 <para>Environment to typeset the math text on its own line, in display style
@@ -3136,10 +3830,12 @@
 environment honors the <literal>fleqn</literal> option.)
 </para>
 <para>The output from this example is centered and alone on its line. 
-</para><screen>\begin{displaymath}
+</para>
+<screen>\begin{displaymath}
   \int_1^2 x^2\,dx=7/3
 \end{displaymath}
-</screen><para>Also, the integral sign is larger than the inline version  
+</screen>
+<para>Also, the integral sign is larger than the inline version  
 <literal>\( \int_1^2 x^2\,dx=7/3 \)</literal> produces.
 </para>
 
@@ -3211,9 +3907,9 @@
 <para>Synopsis:
 </para>
 <screen>\begin{enumerate}
-\item[<replaceable>optional label of first item</replaceable>] text of first item
-\item[<replaceable>optional label of second item</replaceable>] text of second item
-...
+  \item[<replaceable>optional label of first item</replaceable>] <replaceable>text of first item</replaceable>
+  \item[<replaceable>optional label of second item</replaceable>] <replaceable>text of second item</replaceable>
+  ...
 \end{enumerate}
 </screen>
 <para>Environment to produce a numbered list of items.  The format of the
@@ -3248,15 +3944,15 @@
 the outermost level.
 </para>
 <orderedlist numeration="arabic"><listitem><para>arabic number followed by a period: ‘<literal>1.</literal>’, ‘<literal>2.</literal>’, …
-</para></listitem><listitem><para>lower case letter inside parentheses: ‘<literal>(a)</literal>’, ‘<literal>(b)</literal>’ …
-</para></listitem><listitem><para>lower case roman numeral followed by a period: ‘<literal>i.</literal>’, ‘<literal>ii.</literal>’, …
-</para></listitem><listitem><para>upper case letter followed by a period: ‘<literal>A.</literal>’, ‘<literal>B.</literal>’, …
+</para></listitem><listitem><para>lowercase letter inside parentheses: ‘<literal>(a)</literal>’, ‘<literal>(b)</literal>’ …
+</para></listitem><listitem><para>lowercase roman numeral followed by a period: ‘<literal>i.</literal>’, ‘<literal>ii.</literal>’, …
+</para></listitem><listitem><para>uppercase letter followed by a period: ‘<literal>A.</literal>’, ‘<literal>B.</literal>’, …
 </para></listitem></orderedlist>
 <indexterm role="fn"><primary>\enumi</primary></indexterm>
 <indexterm role="fn"><primary>\enumii</primary></indexterm>
 <indexterm role="fn"><primary>\enumiii</primary></indexterm>
 <indexterm role="fn"><primary>\enumiv</primary></indexterm>
-<para>The <literal>enumerate</literal> environment uses the counters <literal>\enumi</literal> through
+<anchor id="enumerate-enumi"/><anchor id="enumerate-enumii"/><anchor id="enumerate-enumiii"/><anchor id="enumerate-enumiv"/><para>The <literal>enumerate</literal> environment uses the counters <literal>\enumi</literal> through
 <literal>\enumiv</literal> (see <link linkend="Counters">Counters</link>).
 </para>
 <para>For other major &latex; labeled list environments, see
@@ -3269,7 +3965,7 @@
 <indexterm role="fn"><primary>\labelenumii</primary></indexterm>
 <indexterm role="fn"><primary>\labelenumiii</primary></indexterm>
 <indexterm role="fn"><primary>\labelenumiv</primary></indexterm>
-<para>To change the format of the label use <literal>\renewcommand</literal>
+<anchor id="enumerate-labelenumi"/><anchor id="enumerate-labelenumii"/><anchor id="enumerate-labelenumiii"/><anchor id="enumerate-labelenumiv"/><para>To change the format of the label use <literal>\renewcommand</literal>
 (see <link linkend="_005cnewcommand-_0026-_005crenewcommand">\newcommand & \renewcommand</link>) on the commands <literal>\labelenumi</literal>
 through <literal>\labelenumiv</literal>. For instance, this first level list will be
 labelled with uppercase letters, in boldface, and without a trailing
@@ -3299,17 +3995,16 @@
 <indexterm role="cp"><primary>align environment, from <literal>amsmath</literal></primary></indexterm>
 <indexterm role="cp"><primary>amsmath package, replacing <literal>eqnarray</literal></primary></indexterm>
 <indexterm role="cp"><primary>Madsen, Lars</primary></indexterm>
-<para>First, a caveat: the <literal>eqnarray</literal> environment is depreciated.  It has
-infelicities that cannot be overcome, including spacing that is
-inconsistent with other mathematics elements (see the article “Avoid
-eqnarray!” by Lars Madsen
+<para>The <literal>eqnarray</literal> environment is obsolete.  It has infelicities,
+including spacing that is inconsistent with other mathematics elements.
+(See “Avoid eqnarray!” by Lars Madsen
 <ulink url="http://tug.org/TUGboat/tb33-1/tb103madsen.pdf">http://tug.org/TUGboat/tb33-1/tb103madsen.pdf</ulink>).  New documents
 should include the <filename>amsmath</filename> package and use the displayed
 mathematics environments provided there, such as the <literal>align</literal>
-environment.
+environment.  We include a description only for completeness and for
+working with old documents.
 </para>
-<para>Nevertheless, for completeness and for a reference when working with old
-documents, a synopsis:
+<para>Synopsis:
 </para>
 <screen>\begin{eqnarray} 
   <replaceable>first formula left</replaceable>  &<replaceable>first formula middle</replaceable>  &<replaceable>first formula right</replaceable> \\
@@ -3370,21 +4065,22 @@
 <para>Synopsis:
 </para>
 <screen>\begin{equation}
-  math text
+  <replaceable>mathematical text</replaceable>
 \end{equation}
 </screen>
-<para>Make a <literal>displaymath</literal> environment (see <link linkend="displaymath">displaymath</link>) with an
-equation number in the right margin.
+<para>The same as a <literal>displaymath</literal> environment (see <link linkend="displaymath">displaymath</link>)
+except that &latex; puts an equation number flush to the right margin.
+The equation number is generated using the <literal>equation</literal> counter.
 </para>
-<para>The equation number is generated using the <literal>equation</literal> counter.
-</para>
 <para>You should have no blank lines between <literal>\begin{equation}</literal> and
 <literal>\begin{equation}</literal>, or &latex; will tell you that there is a
-missing dollar sign, $<literal>$</literal>.
+missing dollar sign.
 </para>
-<para>Note that the <filename>amsmath</filename> package has extensive displayed equation
-facilities.  Those facilities are the best approach for such output in
-new documents.
+<indexterm role="cp"><primary>package, <literal>amsmath</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>amsmath</literal> package</primary></indexterm>
+
+<para>The package <filename>amsmath</filename> package has extensive displayed equation
+facilities.  New documents should include this package.
 </para>
 
 </sect1>
@@ -3400,50 +4096,55 @@
 <para>Synopsis:
 </para>
 <screen>\begin{figure}[<replaceable>placement</replaceable>]
-  figure body
-\caption[<replaceable>loftitle</replaceable>]{<replaceable>title</replaceable>}
-\label{<replaceable>label}</replaceable>
+  <replaceable>figure body</replaceable>
+  \caption[<replaceable>loftitle</replaceable>]{<replaceable>title</replaceable>}  % optional
+  \label{<replaceable>label}</replaceable>              % optional
 \end{figure}
 </screen>
-<para>or
+<para>or:
 </para>
 <screen>\begin{figure*}[<replaceable>placement</replaceable>]
-  figure body
-\caption[<replaceable>loftitle</replaceable>]{<replaceable>title</replaceable>}
-\label{<replaceable>label}</replaceable>
+  <replaceable>figure body</replaceable>
+  \caption[<replaceable>loftitle</replaceable>]{<replaceable>title</replaceable>}  % optional
+  \label{<replaceable>label}</replaceable>              % optional  
 \end{figure*}
 </screen>
-<para>A class of floats (see <link linkend="Floats">Floats</link>).  Because they cannot be split across
-pages, they are not typeset in sequence with the normal text but instead
-are “floated” to a convenient place, such as the top of a following
-page.
+<para>Figures are for material that is not part of the normal text.  An
+example is material that you cannot have split between two pages, such
+as a graphic.  Because of this, &latex; does not typeset figures in
+sequence with normal text but instead “floats” them to a convenient
+place, such as the top of a following page (see <link linkend="Floats">Floats</link>).
 </para>
-<para>For the possible values of <replaceable>placement</replaceable> and their effect on the 
-float placement algorithm, see <link linkend="Floats">Floats</link>.
+<para>The <replaceable>figure body</replaceable> can consist of imported graphics
+(see <link linkend="Graphics">Graphics</link>), or text, &latex; commands, etc.  It is typeset in a
+<literal>parbox</literal> of width <literal>\textwidth</literal>.
 </para>
+<para>The possible values of <replaceable>placement</replaceable> are <literal>h</literal> for ‘<literal>here</literal>’,
+<literal>t</literal> for ‘<literal>top</literal>’, <literal>b</literal> for ‘<literal>bottom</literal>’, and <literal>p</literal> for
+‘<literal>on a separate page of floats</literal>’.  For the effect of these options on
+the float placement algorithm, see <link linkend="Floats">Floats</link>.
+</para>
 <para>The starred form <literal>figure*</literal> is used when a document is in
 double-column mode (see <link linkend="_005ctwocolumn">\twocolumn</link>).  It produces a figure that
 spans both columns, at the top of the page.  To add the possibility of
 placing at a page bottom see the discussion of <replaceable>placement</replaceable> <literal>b</literal>
 in <link linkend="Floats">Floats</link>.
 </para>
-<para>The figure body is typeset in a <literal>parbox</literal> of width <literal>\textwidth</literal>
-and so it can contain text, commands, etc.
-</para>
 <para>The label is optional; it is used for cross references (see <link linkend="Cross-references">Cross
 references</link>).
 <indexterm role="fn"><primary>\caption</primary></indexterm>
 The optional <literal>\caption</literal> command specifies caption text for the
 figure.  By default it is numbered.  If <replaceable>loftitle</replaceable> is present, it is
-used in the list of figures instead of <replaceable>title</replaceable> (see <link linkend="Tables-of-contents">Tables of
-contents</link>).
+used in the list of figures instead of <replaceable>title</replaceable> (see <link linkend="Table-of-contents-etc_002e">Table of
+contents etc.</link>).
 </para>
-<para>This example makes a figure out of a graphic.  It requires one of the
-packages <filename>graphics</filename> or <filename>graphicx</filename>.  The graphic, with its
-caption, will be placed at the top of a page or, if it is pushed to the
+<para>This example makes a figure out of a graphic.  &latex; will place that
+graphic and its caption at the top of a page or, if it is pushed to the
 end of the document, on a page of floats.
 </para>
-<screen>\begin{figure}[t]
+<screen>\usepackage{graphicx}  % in preamble
+  ...
+\begin{figure}[t]
   \centering
   \includegraphics[width=0.5\textwidth]{CTANlion.png}
   \caption{The CTAN lion, by Duane Bibby}
@@ -3522,19 +4223,36 @@
 <indexterm role="cp"><primary>left-justifying text, environment for</primary></indexterm>
 <indexterm role="cp"><primary>ragged right text, environment for</primary></indexterm>
 
+<para>Synopsis:
+</para>
 <screen>\begin{flushleft}
-<replaceable>line1</replaceable> \\
-<replaceable>line2</replaceable> \\
-...
+  <replaceable>line1</replaceable> \\
+  <replaceable>line2</replaceable> \\
+  ...
 \end{flushleft}
 </screen>
 <indexterm role="fn"><primary>\\ for <literal>flushleft</literal></primary></indexterm>
-<para>The <literal>flushleft</literal> environment allows you to create a paragraph
-consisting of lines that are flush to the left-hand margin and ragged
-right. Each line must be terminated with the string <literal>\\</literal>.
+<para>An environment that creates a paragraph whose lines are flush to the
+left-hand margin, and ragged right. If you have lines that are too long
+then &latex; will linebreak them in a way that avoids hyphenation and
+stretching or shrinking spaces.  To force a new line use a double
+backslash, <literal>\\</literal>.  For the declaration form
+see <link linkend="_005craggedright">\raggedright</link>.
 </para>
+<para>This creates a box of text that is at most 3 inches wide, with the text
+flush left and ragged right.
+</para>
+<screen>\noindent\begin{minipage}{3in}
+\begin{flushleft}
+  A long sentence that will be broken by \LaTeX{}
+    at a convenient spot. \\
+  And, a fresh line forced by the double backslash.
+\end{flushleft}
+\end{minipage}
+</screen>
 
 
+
 <sect2 label="8.12.1" id="_005craggedright">
 <title><literal>\raggedright</literal></title>
 
@@ -3543,16 +4261,38 @@
 <indexterm role="cp"><primary>left-justifying text</primary></indexterm>
 <indexterm role="cp"><primary>justification, ragged right</primary></indexterm>
 
-<para>The <literal>\raggedright</literal> declaration corresponds to the
-<literal>flushleft</literal> environment.  This declaration can be used inside an
-environment such as <literal>quote</literal> or in a <literal>parbox</literal>.
+<para>Synopses:
 </para>
+<screen>{\raggedright  ... }
+</screen>
+<para>or
+</para>
+<screen>\begin{<replaceable>environment</replaceable>} \raggedright
+  ...
+\end{<replaceable>environment</replaceable>}
+</screen>
+<para>A declaration which causes lines to be flush to the left margin and
+ragged right. It can be used inside an environment such as <literal>quote</literal>
+or in a <literal>parbox</literal>.  For the environment form
+see <link linkend="flushleft">flushleft</link>.
+</para>
 <para>Unlike the <literal>flushleft</literal> environment, the <literal>\raggedright</literal>
 command does not start a new paragraph; it only changes how &latex;
 formats paragraph units.  To affect a paragraph unit’s format, the
 scope of the declaration must contain the blank line or <literal>\end</literal>
 command that ends the paragraph unit.
 </para>
+<para>Here <literal>\raggedright</literal> in each second column keeps &latex; from doing
+very awkward typesetting to fit the text into the narrow column.  Note
+that <literal>\raggedright</literal> is inside the curly braces <literal>{...}</literal> to
+delimit its effect.
+</para>
+<screen>\begin{tabular}{rp{2in}}
+  Team alpha  &{\raggedright This team does all the real work.} \\
+  Team beta   &{\raggedright This team ensures that the water
+                cooler is never empty.}                         \\
+\end{tabular}
+</screen>
 
 </sect2>
 </sect1>
@@ -3566,16 +4306,21 @@
 <indexterm role="cp"><primary>right-justifying text, environment for</primary></indexterm>
 
 <screen>\begin{flushright}
-<replaceable>line1</replaceable> \\
-<replaceable>line2</replaceable> \\
-...
+  <replaceable>line1</replaceable> \\
+  <replaceable>line2</replaceable> \\
+  ...
 \end{flushright}
 </screen>
 <indexterm role="fn"><primary>\\ (for <literal>flushright</literal>)</primary></indexterm>
-<para>The <literal>flushright</literal> environment allows you to create a paragraph
-consisting of lines that are flush to the right-hand margin and ragged
-left.  Each line must be terminated with the control sequence <literal>\\</literal>.
+<para>An environment that creates a paragraph whose lines are flush to the
+right-hand margin and ragged left. If you have lines that are too long
+to fit the margins then &latex; will linebreak them in a way that
+avoids hyphenation and stretching or shrinking spaces.  To force a new
+line use a double backslash, <literal>\\</literal>.  For the declaration form
+see <link linkend="_005craggedleft">\raggedleft</link>.
 </para>
+<para>For an example related to this environment, see <link linkend="flushleft">flushleft</link>.
+</para>
 
 
 <sect2 label="8.13.1" id="_005craggedleft">
@@ -3586,16 +4331,29 @@
 <indexterm role="cp"><primary>justification, ragged left</primary></indexterm>
 <indexterm role="cp"><primary>right-justifying text</primary></indexterm>
 
-<para>The <literal>\raggedleft</literal> declaration corresponds to the
-<literal>flushright</literal> environment.  This declaration can be used inside an
-environment such as <literal>quote</literal> or in a <literal>parbox</literal>.
+<para>Synopses:
 </para>
+<screen>{\raggedleft  ... }
+</screen>
+<para>or
+</para>
+<screen>\begin{<replaceable>environment</replaceable>} \raggedleft
+  ...
+\end{<replaceable>environment</replaceable>}
+</screen>
+<para>A declaration which causes lines to be flush to the right margin and
+ragged left. It can be used inside an environment such as <literal>quote</literal>
+or in a <literal>parbox</literal>.  For the environment form
+see <link linkend="flushright">flushright</link>.
+</para>
 <para>Unlike the <literal>flushright</literal> environment, the <literal>\raggedleft</literal>
 command does not start a new paragraph; it only changes how &latex;
 formats paragraph units.  To affect a paragraph unit’s format, the
 scope of the declaration must contain the blank line or <literal>\end</literal>
 command that ends the paragraph unit.
 </para>
+<para>For an example related to this environment, see <link linkend="_005craggedright">\raggedright</link>.
+</para>
 
 </sect2>
 </sect1>
@@ -3609,29 +4367,30 @@
 <indexterm role="cp"><primary>lists of items</primary></indexterm>
 <indexterm role="cp"><primary>unordered lists</primary></indexterm>
 <indexterm role="cp"><primary>bulleted lists</primary></indexterm>
+<indexterm role="cp"><primary>bullet lists</primary></indexterm>
 
 <para>Synopsis:
 </para>
 <screen>\begin{itemize}
-\item[<replaceable>optional label of first item</replaceable>] text of first item
-\item[<replaceable>optional label of second item</replaceable>] text of second item
-...
+  \item[<replaceable>optional label of first item</replaceable>] <replaceable>text of first item</replaceable>
+  \item[<replaceable>optional label of second item</replaceable>] <replaceable>text of second item</replaceable>
+  ...
 \end{itemize}
 </screen>
-<para>The <literal>itemize</literal> environment produces an “unordered”, “bulleted”
-list.  The format of the label numbering depends on the nesting level of
-this environment; see below.  Each <literal>itemize</literal> list environment must
-have at least one item; having none causes the &latex; error
-‘<literal>Something's wrong--perhaps a missing \item</literal>’.
+<para>Produce a list that is unordered, sometimes called a bullet list.  The
+environment must have at least one <literal>\item</literal>; having none causes the
+&latex; error ‘<literal>Something's wrong--perhaps a missing \item</literal>’.
 </para>
-<para>This example gives a two-item list.  As a top-level list each label
-would come out as a bullet, •.
+<para>This gives a two-item list.
 </para>
 <screen>\begin{itemize}
  \item Pencil and watercolor sketch by Cassandra
  \item Rice portrait 
 \end{itemize}
 </screen>
+<para>As a top-level list each label would come out as a bullet, •.
+The format of the labeling depends on the nesting level; see below.
+</para>
 <indexterm role="fn"><primary>\item</primary></indexterm>
 <para>Start list items with the <literal>\item</literal> command (see <link linkend="_005citem">\item</link>).  If you
 give <literal>\item</literal> an optional argument by following it with square
@@ -3645,11 +4404,11 @@
 <indexterm role="fn"><primary>\labelitemii</primary></indexterm>
 <indexterm role="fn"><primary>\labelitemiii</primary></indexterm>
 <indexterm role="fn"><primary>\labelitemiv</primary></indexterm>
-<para>Itemized lists can be nested within one another, up to four levels deep.
+<anchor id="itemize-labelitemi"/><anchor id="itemize-labelitemii"/><anchor id="itemize-labelitemiii"/><anchor id="itemize-labelitemiv"/><para>Itemized lists can be nested within one another, up to four levels deep.
 They can also be nested within other paragraph-making environments, such
 as <literal>enumerate</literal> (see <link linkend="enumerate">enumerate</link>).  The <literal>itemize</literal> environment
 uses the commands <literal>\labelitemi</literal> through <literal>\labelitemiv</literal> to
-produce the default label (this also uses the convention of lower case
+produce the default label (this also uses the convention of lowercase
 roman numerals at the end of the command names that signify the nesting
 level).  These are the default marks at each level.
 </para>
@@ -3670,10 +4429,10 @@
 <indexterm role="fn"><primary>\leftmarginiv</primary></indexterm>
 <indexterm role="fn"><primary>\leftmarginv</primary></indexterm>
 <indexterm role="fn"><primary>\leftmarginvi</primary></indexterm>
-<para>The distance between the left margin of the enclosing environment and
+<anchor id="itemize-leftmargin"/><anchor id="itemize-leftmargini"/><anchor id="itemize-leftmarginii"/><anchor id="itemize-leftmarginiii"/><anchor id="itemize-leftmarginiv"/><anchor id="itemize-leftmarginv"/><anchor id="itemize-leftmarginvi"/><para>The distance between the left margin of the enclosing environment and
 the left margin of the <literal>itemize</literal> list is determined by the
 parameters <literal>\leftmargini</literal> through <literal>\leftmarginvi</literal>.  (Note the
-convention of using lower case roman numerals a the end of the command
+convention of using lowercase roman numerals a the end of the command
 name to denote the nesting level.)  The defaults are: <literal>2.5em</literal> in
 level 1 (<literal>2em</literal> in two-column mode), <literal>2.2em</literal> in level 2,
 <literal>1.87em</literal> in level 3, and <literal>1.7em</literal> in level 4, with smaller
@@ -3695,7 +4454,7 @@
 space between items.  Here is an example defining an <literal>itemize*</literal>
 environment with no extra spacing between items, or between paragraphs
 within a single item (<literal>\parskip</literal> is not list-specific,
-see <link linkend="_005cparskip">\parskip</link>):
+see <link linkend="_005cparindent-_0026-_005cparskip">\parindent & \parskip</link>):
 </para>
 <screen>\newenvironment{itemize*}%
   {\begin{itemize}%
@@ -3728,34 +4487,33 @@
 <para>Synopsis:
 </para>
 <screen>\begin{list}{<replaceable>labeling</replaceable>}{<replaceable>spacing</replaceable>}
-\item[<replaceable>optional label of first item</replaceable>] text of first item
-\item[<replaceable>optional label of second item</replaceable>] text of second item
-...
+  \item[<replaceable>optional label of first item</replaceable>] <replaceable>text of first item</replaceable>
+  \item[<replaceable>optional label of second item</replaceable>] <replaceable>text of second item</replaceable>
+  ...
 \end{list}
 </screen>
-<para>The <literal>list</literal> environment is a generic environment for constructing
-more specialized lists.  It is most often used to create lists via the
-<literal>description</literal>, <literal>enumerate</literal>, and <literal>itemize</literal> environments
-(see <link linkend="description">description</link>, <link linkend="enumerate">enumerate</link>, and <link linkend="itemize">itemize</link>).
+<para>An environment for constructing lists.
 </para>
-<para>Also, many standard &latex; environments that are not visually lists
-are constructed using <literal>list</literal>, including <literal>quotation</literal>,
-<literal>quote</literal>, <literal>center</literal>, <literal>verbatim</literal>, and plenty more
-(see <link linkend="quotation-and-quote">quotation and quote</link>, see <link linkend="center">center</link>, see <link linkend="flushright">flushright</link>).
+<para>Note that this environment does not typically appear in the document
+body.  Most lists created by &latex; authors are the ones that come
+standard: the <literal>description</literal>, <literal>enumerate</literal>, and <literal>itemize</literal>
+environments (see <link linkend="description">description</link>, <link linkend="enumerate">enumerate</link>, and <link linkend="itemize">itemize</link>).
 </para>
-<indexterm role="cp"><primary>package, <literal>enumitem</literal></primary></indexterm>
-<indexterm role="cp"><primary><literal>enumitem</literal> package</primary></indexterm>
-
-<para>The third-party package <literal>enumitem</literal> is useful for customizing lists.
-Here, we describe the <literal>list</literal> environment by defining a new custom
+<para>Instead, the <literal>list</literal> environment is most often used in macros.  For
+example, many standard &latex; environments that do not immediately
+appear to be lists are in fact constructed using <literal>list</literal>, including
+<literal>quotation</literal>, <literal>quote</literal>, and <literal>center</literal> (see <link linkend="quotation-_0026-quote">quotation &
+quote</link>, see <link linkend="center">center</link>).
+</para>
+<para>This uses the <literal>list</literal> environment to define a new custom
 environment.
 </para>
 <screen>\newcounter{namedlistcounter}  % number the items
 \newenvironment{named}
   {\begin{list}
-     {Item~\Roman{namedlistcounter}.} % labeling argument
-     {\usecounter{namedlistcounter}   % spacing argument
-      \setlength{\leftmargin}{3.5em}} % still spacing arg
+     {Item~\Roman{namedlistcounter}.} % labeling 
+     {\usecounter{namedlistcounter}   % set counter
+      \setlength{\leftmargin}{3.5em}} % set spacing 
   }
   {\end{list}}
 
@@ -3765,54 +4523,55 @@
   \item Shows as ``Item~II.''
 \end{named}
 </screen>
-<para>The <literal>list</literal> environment’s mandatory first argument,
-<replaceable>labeling</replaceable>, specifies the default labeling of list items.  It can
-contain text and &latex; commands, as above where it contains both
-‘<literal>Item</literal>’ and ‘<literal>\Roman{...}</literal>’.  &latex; forms the label by
-putting the <replaceable>labeling</replaceable> argument in a box of width
-<literal>\labelwidth</literal>.  If the label is wider than that, the additional
-material extends to the right.  When making an instance of a list you
-can override the default labeling by giving <literal>\item</literal> an optional
-argument by including square braces and the text, as in the above
-<literal>\item[Special label.]</literal>; see <link linkend="_005citem">\item</link>.
+<para>The mandatory first argument <replaceable>labeling</replaceable> specifies the default
+labeling of list items.  It can contain text and &latex; commands, as
+above where it contains both ‘<literal>Item</literal>’ and ‘<literal>\Roman{...}</literal>’.
+&latex; forms the label by putting the <replaceable>labeling</replaceable> argument in a box
+of width <literal>\labelwidth</literal>.  If the label is wider than that, the
+additional material extends to the right.  When making an instance of a
+list you can override the default labeling by giving <literal>\item</literal> an
+optional argument by including square braces and the text, as in the
+above <literal>\item[Special label.]</literal>; see <link linkend="_005citem">\item</link>.
 </para>
+<para>The mandatory second argument <replaceable>spacing</replaceable> has a list of commands.
+This list can be empty.  A command that can go in here is
+<literal>\usecounter{<replaceable>countername</replaceable>}</literal> (see <link linkend="_005cusecounter">\usecounter</link>).  Use this
+to tell &latex; to number the items using the given counter.  The
+counter will be reset to zero each time &latex; enters the environment,
+and the counter is incremented by one each time &latex; encounters an
+<literal>\item</literal> that does not have an optional argument.
+</para>
 <indexterm role="fn"><primary>\makelabel</primary></indexterm>
-<para>The label box is constructed by the command <literal>\makelabel</literal>.  By
-default it positions the contents flush right.  It takes one argument,
-the label.  It typesets the contents in LR mode. An example of changing
-its definition is that to the above example before the definition of the
-<literal>named</literal> environment add
+<anchor id="list-makelabel"/><para>Another command that can go in <replaceable>spacing</replaceable> is
+<literal>\makelabel</literal>, which constructs the label box.  By default it puts
+the contents flush right.  Its only argument is the label, which it
+typesets in LR mode (see <link linkend="Modes">Modes</link>). One example of changing its
+definition is that to the above <literal>named</literal> example, before the
+definition of the environment add
 <literal>\newcommand{\namedmakelabel}[1]{\textsc{#1}}</literal>, and between
 the <literal>\setlength</literal> command and the parenthesis that closes the
 <replaceable>spacing</replaceable> argument also add <literal>\let\makelabel\namedmakelabel</literal>.
 Then the items will be typeset in small caps.  Similarly, changing the
 second code line to <literal>\let\makelabel\fbox</literal> puts the labels inside a
-framed box.  Another example is at the bottom of this entry.
+framed box.  Another example of the <literal>\makelabel</literal> command is below,
+in the definition of the <literal>redlabel</literal> environment.
 </para>
-<para>The mandatory second argument <replaceable>spacing</replaceable> can have a list of
-commands to redefine the spacing parameters for the list, such as
-<literal>\setlength{\labelwidth}{2em}</literal>.  If this argument is empty,
-i.e., <literal>{}</literal>, then the list will have the default spacing given
-below.  To number the items using a counter, put
-<literal>\usecounter{<replaceable>countername</replaceable>}</literal> in this argument
-(see <link linkend="_005cusecounter">\usecounter</link>).
+<para>Also often in <replaceable>spacing</replaceable> are commands to redefine the spacing for the
+list.  Below are the spacing parameters with their default values.
+(Default values for derived environments such as <literal>itemize</literal> can be
+different than the values shown here.) See also the figure that follows
+the list.  Each is a length (see <link linkend="Lengths">Lengths</link>).  The vertical spaces are
+normally rubber lengths, with <literal>plus</literal> and <literal>minus</literal> components,
+to give &tex; flexibility in setting the page.  Change each with a
+command such as <literal>\setlength{itemsep}{2pt plus1pt minus1pt}</literal>.
+For some effects these lengths should be zero or negative.
 </para>
-<para>Below are the spacing parameters for list formatting.  See also the
-figure below.  Each is a length (see <link linkend="Lengths">Lengths</link>).  The vertical
-spaces are normally rubber lengths, with <literal>plus</literal> and <literal>minus</literal>
-components, to give &tex; flexibility in setting the page.  Change
-each with a command such as <literal>\setlength{itemsep}{2pt plus1pt
-minus1pt}</literal>.  For some effects these lengths should be zero or
-negative.  Default values for derived environments such as
-<literal>itemize</literal> can be changed from the values shown here for the basic
-<literal>list</literal>.
-</para>
 <variablelist><varlistentry><term><indexterm role="fn"><primary>\itemindent</primary></indexterm><literal>\itemindent</literal>
-</term><listitem><para>Extra horizontal space indentation, beyond <literal>leftmargin</literal>, of the
+</term><listitem><anchor id="list-itemindent"/><para>Extra horizontal space indentation, beyond <literal>leftmargin</literal>, of the
 first line each item.  Its default value is <literal>0pt</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\itemsep</primary></indexterm><literal>\itemsep</literal>
-</term><listitem><para>Vertical space between items, beyond the <literal>\parsep</literal>.  The defaults
+</term><listitem><anchor id="list-itemsep"/><para>Vertical space between items, beyond the <literal>\parsep</literal>.  The defaults
 for the first three levels in &latex;’s ‘<literal>article</literal>’, ‘<literal>book</literal>’,
 and ‘<literal>report</literal>’ classes at 10 point size are: <literal>4pt plus2pt
 minus1pt</literal>, <literal>\parsep</literal> (that is, <literal>2pt plus1pt minus1pt</literal>), and
@@ -3824,12 +4583,12 @@
 <literal>\topsep</literal> (that is, <literal>2.5pt plus1pt minus1pt</literal>).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\labelsep</primary></indexterm><literal>\labelsep</literal>
-</term><listitem><para>Horizontal space between the label and text of an item.
+</term><listitem><anchor id="list-labelsep"/><para>Horizontal space between the label and text of an item.
 The default for &latex;’s ‘<literal>article</literal>’, ‘<literal>book</literal>’,
 and ‘<literal>report</literal>’ classes is <literal>0.5em</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\labelwidth</primary></indexterm><literal>\labelwidth</literal>
-</term><listitem><para>Horizontal width.  The box containing the label is nominally this wide.
+</term><listitem><anchor id="list-labelwidth"/><para>Horizontal width.  The box containing the label is nominally this wide.
 If <literal>\makelabel</literal> returns text that is wider than this then the first
 line of the item will be indented to make room for this extra material.
 If <literal>\makelabel</literal> returns text of width less than or equal to
@@ -3850,7 +4609,7 @@
 environment.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\leftmargin</primary></indexterm><literal>\leftmargin</literal>
-</term><listitem><para>Horizontal space between the left margin of the enclosing environment
+</term><listitem><anchor id="list-leftmargin"/><para>Horizontal space between the left margin of the enclosing environment
 (or the left margin of the page if this is a top-level list), and the
 left margin of this list.  It must be non-negative.
 </para>
@@ -3867,13 +4626,13 @@
 <literal>2.2em</literal>, and <literal>\leftmarginiii</literal> is <literal>1.87em</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\listparindent</primary></indexterm><literal>\listparindent</literal>
-</term><listitem><para>Horizontal space of additional line indentation, beyond
+</term><listitem><anchor id="list-listparindent"/><para>Horizontal space of additional line indentation, beyond
 <literal>\leftmargin</literal>, for second and subsequent paragraphs within a list
 item.  A negative value makes this an “outdent”.  Its default value
 is <literal>0pt</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\parsep</primary></indexterm><literal>\parsep</literal>
-</term><listitem><para>Vertical space between paragraphs within an item.  In the ‘<literal>book</literal>’
+</term><listitem><anchor id="list-parsep"/><para>Vertical space between paragraphs within an item.  In the ‘<literal>book</literal>’
 and ‘<literal>article</literal>’ classes The defaults for the first three levels in
 &latex;’s ‘<literal>article</literal>’, ‘<literal>book</literal>’, and ‘<literal>report</literal>’ classes at 10
 point size are: <literal>4pt plus2pt minus1pt</literal>, <literal>2pt plus1pt
@@ -3883,7 +4642,7 @@
 minus1pt</literal>, <literal>2.5pt plus1pt minus1pt</literal>, and <literal>0pt</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\partopsep</primary></indexterm><literal>\partopsep</literal>
-</term><listitem><para>Vertical space added, beyond <literal>\topsep</literal>+<literal>\parskip</literal>, to the top
+</term><listitem><anchor id="list-partopsep"/><para>Vertical space added, beyond <literal>\topsep</literal>+<literal>\parskip</literal>, to the top
 and bottom of the entire environment if the list instance is preceded by
 a blank line.  (A blank line in the &latex; source before the list
 changes spacing at both the top and bottom of the list; whether the line
@@ -3898,20 +4657,20 @@
 minus2pt</literal>, and <literal>1pt plus0pt minus1pt</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\rightmargin</primary></indexterm><literal>\rightmargin</literal>
-</term><listitem><para>Horizontal space between the right margin of the list and the right
+</term><listitem><anchor id="list-rightmargin"/><para>Horizontal space between the right margin of the list and the right
 margin of the enclosing environment.  Its default value is <literal>0pt</literal>.
 It must be non-negative.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\topsep</primary></indexterm><literal>\topsep</literal>
-</term><listitem><para>Vertical space added to both the top and bottom of the list, in addition
-to <literal>\parskip</literal> (see <link linkend="_005cparskip">\parskip</link>).  The defaults for the first three
-levels in &latex;’s ‘<literal>article</literal>’, ‘<literal>book</literal>’, and ‘<literal>report</literal>’
-classes at 10 point size are: <literal>8pt plus2pt minus4pt</literal>, <literal>4pt
-plus2pt minus1pt</literal>, and <literal>2pt plus1pt minus1pt</literal>.  The defaults at 11
-point are: <literal>9pt plus3pt minus5pt</literal>, <literal>4.5pt plus2pt minus1pt</literal>,
-and <literal>2pt plus1pt minus1pt</literal>.  The defaults at 12 point are:
-<literal>10pt plus4pt minus6pt</literal>, <literal>5pt plus2.5pt minus1pt</literal>, and
-<literal>2.5pt plus1pt minus1pt</literal>.
+</term><listitem><anchor id="list-topsep"/><para>Vertical space added to both the top and bottom of the list, in addition
+to <literal>\parskip</literal> (see <link linkend="_005cparindent-_0026-_005cparskip">\parindent & \parskip</link>).  The defaults for
+the first three levels in &latex;’s ‘<literal>article</literal>’, ‘<literal>book</literal>’, and
+‘<literal>report</literal>’ classes at 10 point size are: <literal>8pt plus2pt minus4pt</literal>,
+<literal>4pt plus2pt minus1pt</literal>, and <literal>2pt plus1pt minus1pt</literal>.  The
+defaults at 11 point are: <literal>9pt plus3pt minus5pt</literal>, <literal>4.5pt
+plus2pt minus1pt</literal>, and <literal>2pt plus1pt minus1pt</literal>.  The defaults at 12
+point are: <literal>10pt plus4pt minus6pt</literal>, <literal>5pt plus2.5pt minus1pt</literal>,
+and <literal>2.5pt plus1pt minus1pt</literal>.
 </para>
 </listitem></varlistentry></variablelist>
 <para>This shows the horizontal and vertical distances.
@@ -3992,17 +4751,23 @@
 page break.
 </para>
 <variablelist><varlistentry><term><indexterm role="fn"><primary>\@beginparpenalty</primary></indexterm><literal>\@beginparpenalty</literal>
-</term><listitem><para>The page breaking penalty for breaking before the list (default <literal>-51</literal>).
+</term><listitem><anchor id="list-beginparpenalty"/><para>The page breaking penalty for breaking before the list (default <literal>-51</literal>).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\@itempenalty</primary></indexterm><literal>\@itempenalty</literal>
-</term><listitem><para>The page breaking penalty for breaking before a list item (default <literal>-51</literal>).
+</term><listitem><anchor id="list-itempenalty"/><para>The page breaking penalty for breaking before a list item (default <literal>-51</literal>).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\@endparpenalty</primary></indexterm><literal>\@endparpenalty</literal>
-</term><listitem><para>The page breaking penalty for breaking after a list (default <literal>-51</literal>).
+</term><listitem><anchor id="list-endparpenalty"/><para>The page breaking penalty for breaking after a list (default <literal>-51</literal>).
 </para>
 </listitem></varlistentry></variablelist>
+<indexterm role="cp"><primary>package, <literal>enumitem</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>enumitem</literal> package</primary></indexterm>
+
+<para>The package <literal>enumitem</literal> is useful for customizing lists.
+</para>
 <para>This example has the labels in red.  They are numbered, and the left
 edge of the label lines up with the left edge of the item text.
+See <link linkend="_005cusecounter">\usecounter</link>.
 </para>
 <screen>\usepackage{color}
 \newcounter{cnt}  
@@ -4030,7 +4795,8 @@
 <screen>\item text of item
 </screen>
 <para>or
-</para><screen>\item[<replaceable>optional-label</replaceable>] text of item
+</para>
+<screen>\item[<replaceable>optional-label</replaceable>] text of item
 </screen>
 <para>An entry in a list.  The entries are prefixed by a label, whose default
 depends on the list type.
@@ -4133,24 +4899,114 @@
         
 <indexterm role="cp"><primary>minipage, creating a</primary></indexterm>
 
+<para>Synopses:
+</para>
+<screen>\begin{minipage}{<replaceable>width</replaceable>}
+  <replaceable>contents</replaceable>
+\end{minipage}
+</screen>
+<para>or
+</para>
 <screen>\begin{minipage}[<replaceable>position</replaceable>][<replaceable>height</replaceable>][<replaceable>inner-pos</replaceable>]{<replaceable>width</replaceable>}
-<replaceable>text</replaceable>
+  <replaceable>contents</replaceable>
 \end{minipage}
 </screen>
-<para>The <literal>minipage</literal> environment typesets its body <replaceable>text</replaceable> in a
-block that will not be broken across pages.  This is similar to the
-<literal>\parbox</literal> command (see <link linkend="_005cparbox">\parbox</link>), but unlike <literal>\parbox</literal>,
-other paragraph-making environments can be used inside a minipage.
+<para>Put <replaceable>contents</replaceable> into a box that is <replaceable>width</replaceable> wide.  This is like a
+small version of a page; it can contain its own footnotes, itemized
+lists, etc. (There are some restrictions, including that it cannot have
+floats.)  This box will not be broken across pages.  So <literal>minipage</literal>
+is similar to <literal>\parbox</literal> (see <link linkend="_005cparbox">\parbox</link>) but here you can have
+paragraphs.
 </para>
-<!-- (xxref positions) -->
-<para>The arguments are the same as for <literal>\parbox</literal> (see <link linkend="_005cparbox">\parbox</link>).
+<para>This example will be 3 inches wide, and has two paragraphs.
 </para>
+<screen>\begin{minipage}{3in}
+  Stephen Kleene was a founder of the Theory of Computation.
+
+  He was a student of Church, wrote three influential texts,
+  was President of the Association for Symbolic Logic,
+  and won the National Medal of Science.
+\end{minipage}
+</screen>
+<para>See below for a discussion of the paragraph indent inside a
+<literal>minipage</literal>.
+</para>
+<para>The required argument <replaceable>width</replaceable> is a rigid length (see <link linkend="Lengths">Lengths</link>).
+It gives the width of the box into which <replaceable>contents</replaceable> are typeset.
+</para>
+<para>There are three optional arguments, <replaceable>position</replaceable>, <replaceable>height</replaceable>, and
+<replaceable>inner-pos</replaceable>.  You need not include all three. For example, get the
+default <replaceable>position</replaceable> and set the <replaceable>height</replaceable> with
+<literal>\begin{minipage}[c][2.54cm] <replaceable>contents</replaceable> \end{minipage}</literal>.
+(Get the natural height with an empty argument, <literal>[]</literal>.)
+</para>
+<para>The optional argument <replaceable>position</replaceable> governs how the <literal>minipage</literal>
+vertically aligns with the surrounding material.
+</para>
+<variablelist><varlistentry><term><literal>c</literal>
+</term><listitem><para>(synonym <literal>m</literal>) Default.  Positions the <literal>minipage</literal> so its
+vertical center lines up with the center of the adjacent text line (what
+Plain &tex; calls <literal>\vcenter</literal>).
+</para>
+</listitem></varlistentry><varlistentry><term><literal>t</literal>
+</term><listitem><para>Match the top line in the <literal>minipage</literal> with the baseline of the
+surrounding text (Plain &tex;’s <literal>\vtop</literal>.
+</para>
+</listitem></varlistentry><varlistentry><term><literal>b</literal>
+</term><listitem><para>Match the bottom line in the <literal>minipage</literal> with the baseline of the
+surrounding text (Plain &tex;’s <literal>\vbox</literal>.
+</para></listitem></varlistentry></variablelist>
+<para>To see the effects of these, contrast running this
+</para>
+<screen>---\begin{minipage}[c]{0.25in}
+  first\\ second\\ third
+\end{minipage}
+</screen>
+<para>with the results of changing <literal>c</literal> to <literal>b</literal> or <literal>t</literal>.
+</para>
+<para>The optional argument <replaceable>height</replaceable> is a rigid length (see <link linkend="Lengths">Lengths</link>).
+It sets the height of the <literal>minipage</literal>.  You can enter any value
+larger than, or equal to, or smaller than the <literal>minipage</literal>’s natural
+height and &latex; will not give an error or warning.  You can also set
+it to a height of zero or a negative value.
+</para>
+<para>The final optional argument <replaceable>inner-pos</replaceable> controls the placement of
+<replaceable>content</replaceable> inside the box. These are the possible values are (the
+default is the value of <replaceable>position</replaceable>).
+</para>
+<variablelist><varlistentry><term><literal>t</literal>
+</term><listitem><para>Place <replaceable>content</replaceable> at the top of the box.
+</para>
+</listitem></varlistentry><varlistentry><term><literal>c</literal>
+</term><listitem><para>Place it in the vertical center.
+</para>
+</listitem></varlistentry><varlistentry><term><literal>b</literal>
+</term><listitem><para>Place it at the box bottom.
+</para>
+</listitem></varlistentry><varlistentry><term><literal>s</literal>
+</term><listitem><para>Stretch <replaceable>contents</replaceable> out vertically; it must contain vertically
+stretchable space.
+</para>
+</listitem></varlistentry></variablelist>
+<para>The <replaceable>inner-pos</replaceable> argument makes sense when the <replaceable>height</replaceable> options
+is set to a value larger than the <literal>minipage</literal>’s natural height.  To
+see the effect of the options, run this example with the various choices
+in place of <literal>b</literal>.
+</para>
+<screen>Text before
+\begin{center}
+  ---\begin{minipage}[c][3in][b]{0.25\textwidth}
+       first\\ second\\ third
+  \end{minipage}              
+\end{center}
+Text after  
+</screen>
 <indexterm role="cp"><primary>indentation of paragraphs, in minipage</primary></indexterm>
 <indexterm role="cp"><primary>paragraph indentation, in minipage</primary></indexterm>
 <indexterm role="fn"><primary>\parindent</primary></indexterm>
-<para>By default, paragraphs are not indented in the <literal>minipage</literal>
-environment.  You can restore indentation with a command such as
-<literal>\setlength{\parindent}{1pc}</literal> command.
+<para>By default paragraphs are not indented in a <literal>minipage</literal>.  Change
+that with a command such as <literal>\setlength{\parindent}{1pc}</literal> at
+the start of <replaceable>contents</replaceable>.
 </para>
 <indexterm role="cp"><primary>footnotes in figures</primary></indexterm>
 <indexterm role="cp"><primary>figures, footnotes in</primary></indexterm>
@@ -4161,9 +5017,46 @@
 uses the <literal>\mpfootnote</literal> counter instead of the ordinary
 <literal>footnote</literal> counter (see <link linkend="Counters">Counters</link>).
 </para>
-<para>However, don’t put one minipage inside another if you are using
-footnotes; they may wind up at the bottom of the wrong minipage.
+<para>This puts the footnote at the bottom of the table, not the bottom of the
+page.
 </para>
+<screen>\begin{center}           % center the minipage on the line
+\begin{minipage}{2.5in}
+  \begin{center}         % center the table inside the minipage
+    \begin{tabular}{ll}
+      \textsc{Monarch}  &\textsc{Reign}             \\ \hline
+      Elizabeth II      &63 years\footnote{to date} \\
+      Victoria          &63 years                   \\
+      George III        &59 years
+    \end{tabular}
+  \end{center}  
+\end{minipage}
+\end{center}
+</screen>
+<para>If you nest minipages then there is an oddness when using footnotes.
+Footnotes appear at the bottom of the text ended by the next
+<literal>\end{minipage}</literal> which may not be their logical place.
+</para>
+<para>This puts a table containing data side by side with a map graphic.  They
+are vertically centered.
+</para>
+<screen>\newcommand*{\vcenteredhbox}[1]{\begin{tabular}{@{}c@{}}#1\end{tabular}}
+  ...
+\begin{center}
+  \vcenteredhbox{\includegraphics[width=0.3\textwidth]{nyc.png}}
+  \hspace{0.1\textwidth}
+  \begin{minipage}{0.5\textwidth}
+    \begin{tabular}{r|l}
+      \multicolumn{1}{r}{Borough} &Pop (million)  \\ \hline
+      The Bronx      &$1.5$  \\
+      Brooklyn       &$2.6$  \\
+      Manhattan      &$1.6$  \\
+      Queens         &$2.3$  \\
+      Staten Island  &$0.5$  
+    \end{tabular}
+  \end{minipage}              
+\end{center}
+</screen>
 
 </sect1>
 <sect1 label="8.19" id="picture">
@@ -4175,356 +5068,643 @@
 <indexterm role="cp"><primary>creating pictures</primary></indexterm>
 <indexterm role="cp"><primary>pictures, creating</primary></indexterm>
 
+<para>Synopses: 
+</para><screen>\begin{picture}(<replaceable>width</replaceable>,<replaceable>height</replaceable>)
+   <replaceable>picture commands</replaceable> 
+\end{picture}
+</screen>
+<para>or
+</para>
 <screen>\begin{picture}(<replaceable>width</replaceable>,<replaceable>height</replaceable>)(<replaceable>xoffset</replaceable>,<replaceable>yoffset</replaceable>)
-… <replaceable>picture commands</replaceable> …
+  <replaceable>picture commands</replaceable>
 \end{picture}
 </screen>
+<para>An environment to create simple pictures containing lines, arrows,
+boxes, circles, and text.  Note that while this environment is not
+obsolete, new documents typically use much more powerful graphics
+creation systems, such as <literal>TikZ</literal>, <literal>PSTricks</literal>, <literal>MetaPost</literal>,
+or <literal>Asymptote</literal>.  These are not covered in this document; see CTAN.
+</para>
+<para>This shows the parallelogram law for adding vectors.
+</para>
 <indexterm role="fn"><primary>\unitlength</primary></indexterm>
-<para>The <literal>picture</literal> environment allows you to create just about any
-kind of picture you want containing text, lines, arrows and circles.
-You tell &latex; where to put things in the picture by specifying
-their coordinates.  A coordinate is a number that may have a decimal
-point and a minus sign—a number like <literal>5</literal>, <literal>0.3</literal> or
-<literal>-3.1416</literal>.  A coordinate specifies a length in multiples of the
-unit length <literal>\unitlength</literal>, so if <literal>\unitlength</literal> has been set
-to <literal>1cm</literal>, then the coordinate 2.54 specifies a length of 2.54
-centimeters.
+<screen>\setlength{\unitlength}{1cm}
+\begin{picture}(6,6)      % picture box will be 6cm wide by 6cm tall
+  \put(0,0){\vector(2,1){4}}  % for every 2 over this vector goes 1 up
+    \put(2,1){\makebox(0,0)[l]{\ first leg}}
+  \put(4,2){\vector(1,2){2}}
+    \put(5,4){\makebox(0,0)[l]{\ second leg}}  
+  \put(0,0){\line(1,1){6}}
+    \put(3,3){\makebox(0,0)[r]{sum\ }}  
+\end{picture}
+</screen>
+<para>You can also use this environment to place arbitrary material at an
+exact location.
 </para>
-<para>You should only change the value of <literal>\unitlength</literal>, using the
-<literal>\setlength</literal> command, outside of a <literal>picture</literal> environment.
-The default value is <literal>1pt</literal>.
+<screen>\usepackage{color,graphicx}  % in preamble
+  ...
+\begin{center}
+\setlength{\unitlength}{\textwidth} 
+\begin{picture}(1,1)      % leave space, \textwidth wide and tall
+  \put(0,0){\includegraphics[width=\textwidth]{desertedisland.jpg}}
+  \put(0.25,0.35){\textcolor{red}{X Treasure here}}
+\end{picture}
+\end{center}
+</screen>
+<para>The red X will be precisely a quarter of the <literal>\linewidth</literal> from
+the left margin, and <literal>0.35\linewidth</literal> up from the bottom.  Another
+example of this usage is to put similar code in the page header to get
+repeat material on each of a document’s pages.
 </para>
-<indexterm role="cp"><primary>package, <literal>picture</literal></primary></indexterm>
-<indexterm role="cp"><primary><literal>picture</literal> package</primary></indexterm>
-
-<para>The <literal>picture</literal> package redefine the <literal>picture</literal> environment so
-that everywhere a number is used in a <replaceable>picture commands</replaceable> to specify
-a coordinate, one can use alternatively a length. Be aware however that
-this will prevent scaling those lengths by changing <literal>\unitlength</literal>.
+<para>The <literal>picture</literal> environment has one required argument, a pair of
+numbers (<replaceable>width</replaceable>,<replaceable>height</replaceable>).  Multiply these by the value
+<literal>\unitlength</literal> to get the nominal size of the output, the space that
+&latex; reserves on the output page.  This nominal size need not be how
+large the picture really is; &latex; will draw things from the picture
+outside the picture’s box.
 </para>
-
-<indexterm role="cp"><primary>position, in picture</primary></indexterm>
-<para>A <firstterm>position</firstterm> is a pair of coordinates, such as <literal>(2.4,-5)</literal>, specifying
-the point with x-coordinate <literal>2.4</literal> and y-coordinate <literal>-5</literal>.
-Coordinates are specified in the usual way with respect to an origin,
-which is normally at the lower-left corner of the picture.  Note that
-when a position appears as an argument, it is not enclosed in braces;
-the parentheses serve to delimit the argument.
+<para>This environment also has an optional argument
+(<replaceable>xoffset</replaceable>,<replaceable>yoffset</replaceable>).  It is used to shift the origin.  Unlike
+most optional arguments, this one is not contained in square brackets.
+As with the required argument, it consists of two real numbers.
+Multiply these by <literal>\unitlength</literal> to get the point at the lower-left
+corner of the picture.
 </para>
-<para>The <literal>picture</literal> environment has one mandatory argument which is a
-position (<replaceable>width</replaceable>,<replaceable>height</replaceable>), which specifies the size of the
-picture.  The environment produces a rectangular box with these
-<replaceable>width</replaceable> and <replaceable>height</replaceable>.
+<para>For example, if <literal>\unitlength</literal> has been set to <literal>1mm</literal>, the
+command
 </para>
-<para>The <literal>picture</literal> environment also has an optional position argument
-(<replaceable>xoffset</replaceable>,<replaceable>yoffset</replaceable>), following the size argument, that can
-change the origin.  (Unlike ordinary optional arguments, this argument
-is not contained in square brackets.) The optional argument gives the
-coordinates of the point at the lower-left corner of the picture
-(thereby determining the origin).  For example, if <literal>\unitlength</literal>
-has been set to <literal>1mm</literal>, the command
-</para>
 <screen>\begin{picture}(100,200)(10,20)
 </screen>
-<para>produces a picture of width 100 millimeters and height 200
-millimeters, whose lower-left corner is the point (10,20) and whose
-upper-right corner is therefore the point (110,220).  When you first
-draw a picture, you typically omit the optional argument, leaving the
-origin at the lower-left corner.  If you then want to modify your
+<para>produces a box of width 100 millimeters and height 200 millimeters.  The
+picture’s origin is the point (10mm,20mm) and so the lower-left corner
+is there, and the upper-right corner is at (110mm,220mm).  When you
+first draw a picture you typically omit the optional argument, leaving
+the origin at the lower-left corner.  If you then want to modify your
 picture by shifting everything, you can just add the appropriate
 optional argument.
 </para>
-<para>The environment’s mandatory argument determines the nominal size of the
-picture.  This need bear no relation to how large the picture really is;
-&latex; will happily allow you to put things outside the picture, or even
-off the page.  The picture’s nominal size is used by &latex; in determining
-how much room to leave for it.
+<indexterm role="cp"><primary>position, in picture</primary></indexterm>
+<para>Each <replaceable>picture command</replaceable> tells &latex; where to put something by
+naming its position.  A <firstterm>position</firstterm> is a pair such as <literal>(2.4,-5)</literal>
+giving the x- and y-coordinates.  A <firstterm>coordinate</firstterm> is a not a length,
+it is a real number (it may have a decimal point or a minus sign).  It
+specifies a length in multiples of the unit length <literal>\unitlength</literal>,
+so if <literal>\unitlength</literal> has been set to <literal>1cm</literal>, then the coordinate
+2.54 specifies a length of 2.54 centimeters.
 </para>
-<para>Everything that appears in a picture is drawn by the <literal>\put</literal>
-command. The command
+<para>&latex;’s default for <literal>\unitlength</literal> is <literal>1pt</literal>.  it is a rigid
+length (see <link linkend="Lengths">Lengths</link>).  Change it with the <literal>\setlength</literal> command
+(see <link linkend="_005csetlength">\setlength</link>).  Make this change only outside of a <literal>picture</literal>
+environment.
 </para>
-<screen>\put (11.3,-.3){...}
+<para>Coordinates are given with respect to an origin, which is normally at
+the lower-left corner of the picture.  Note that when a position appears
+as an argument, as with <literal>\put(1,2){...}</literal>, it is not enclosed in
+braces since the parentheses serve to delimit the argument.  Also,
+unlike in some computer graphics systems, larger y-coordinates are
+further up the page.
+</para>
+<para>There are four ways to put things in a picture: <literal>\put</literal>,
+<literal>\multiput</literal>, <literal>\qbezier</literal>, and <literal>\graphpaper</literal>.  The most
+often used is <literal>\put</literal>. This
+</para>
+<screen>\put(11.3,-0.3){...}
 </screen>
-<para>puts the object specified by <literal>...</literal> in the
-picture, with its reference point at coordinates <inlineequation><mathphrase>(11.3,-.3)</mathphrase></inlineequation>.
-The reference points for various objects will be described below.
+<para>places the object with its reference point at coordinates
+<inlineequation><mathphrase>(11.3,-0.3)</mathphrase></inlineequation>.  The reference points for various objects will be
+described below.
+<indexterm role="fn"><primary>LR box</primary></indexterm>
+The <literal>\put</literal> command creates an <firstterm>LR box</firstterm> (see <link linkend="Modes">Modes</link>).
+Anything that can go in an <literal>\mbox</literal> (see <link linkend="_005cmbox-_0026-_005cmakebox">\mbox & \makebox</link>) can
+go in the text argument of the <literal>\put</literal> command.  The reference point
+will be the lower left corner of the box.  In this picture
 </para>
-<indexterm role="fn"><primary>lR box</primary></indexterm>
-<para>The <literal>\put</literal> command creates an <firstterm>LR box</firstterm>.  You can put anything
-that can go in an <literal>\mbox</literal> (see <link linkend="_005cmbox">\mbox</link>) in the text argument of
-the <literal>\put</literal> command.  When you do this, the reference point will
-be the lower left corner of the box.
+<screen>\setlength{\unitlength}{1cm}
+...\begin{picture}(1,1)
+  \put(0,0){\line(1,0){1}}
+  \put(0,0){\line(1,1){1}}
+\end{picture}
+</screen>
+<para>the three dots are just slightly left of the point of the angle formed
+by the two lines.  (Also, <literal>\line(1,1){1}</literal> does not call for a
+line of length one; rather the line has a change in the x coordinate of
+1.)
 </para>
-<para>The <literal>picture</literal> commands are described in the following sections.
+<para>The <literal>\multiput</literal>, <literal>qbezier</literal>, and <literal>graphpaper</literal> commands are
+described below.
 </para>
+<para>This draws a rectangle with a wavy top, using <literal>\qbezier</literal> for
+that curve.
+</para>
+<screen>\begin{picture}(3,1.5)
+  \put(0,0){\vector(1,0){8}}  % x axis
+  \put(0,0){\vector(0,1){4}}  % y axis
+  \put(2,0){\line(0,1){3}}       % left side rectangle
+  \put(4,0){\line(0,1){3.5}}     % right side
+  \qbezier(2,3)(2.5,2.9)(3,3.25)
+    \qbezier(3,3.25)(3.5,3.6)(4,3.5)
+  \thicklines                 % below here, lines are twice as thick
+  \put(2,3){\line(4,1){2}}
+  \put(4.5,2.5){\framebox{Trapezoidal Rule}}
+\end{picture}
+</screen>
 
 
-<sect2 label="8.19.1" id="_005ccircle">
-<title><literal>\circle</literal></title>
+<sect2 label="8.19.1" id="_005cput">
+<title><literal>\put</literal></title>
 
-<indexterm role="fn"><primary>\circle</primary></indexterm>
+<indexterm role="fn"><primary>\put</primary></indexterm>
 
 <para>Synopsis:
 </para>
-<screen>\circle[*]{<replaceable>diameter</replaceable>}
+<screen>\put(<replaceable>xcoord</replaceable>,<replaceable>ycoord</replaceable>){<replaceable>content</replaceable>}
 </screen>
-<para>The <literal>\circle</literal> command produces a circle with a diameter as close
-to the specified one as possible.  The <literal>*</literal>-form of the command
-draws a solid circle.
+<para>Place <replaceable>content</replaceable> at the coordinate (<replaceable>xcoord</replaceable>,<replaceable>ycoord</replaceable>).  See
+the discussion of coordinates and <literal>\unitlength</literal> in <link linkend="picture">picture</link>.
+The <replaceable>content</replaceable> is processed in LR mode (see <link linkend="Modes">Modes</link>) so it cannot
+contain line breaks.
 </para>
-<para>Circles up to 40pt can be drawn.
+<para>This includes the text into the <literal>picture</literal>.
 </para>
+<screen>\put(4.5,2.5){Apply the \textit{unpoke} move}
+</screen>
+<para>The reference point, the location (4.5,2.5), is the lower left of the
+text, at the bottom left of the ‘<literal>A</literal>’.
+</para>
 
 </sect2>
-<sect2 label="8.19.2" id="_005cmakebox-_0028picture_0029">
-<title><literal>\makebox</literal></title>
+<sect2 label="8.19.2" id="_005cmultiput">
+<title><literal>\multiput</literal></title>
 
-<indexterm role="fn"><primary>\makebox (for <literal>picture</literal>)</primary></indexterm>
+<indexterm role="fn"><primary>\multiput</primary></indexterm>
 
 <para>Synopsis:
 </para>
-<screen>\makebox(<replaceable>width</replaceable>,<replaceable>height</replaceable>)[<replaceable>position</replaceable>]{<replaceable>text</replaceable>}
+<screen>\multiput(<replaceable>x</replaceable>,<replaceable>y</replaceable>)(<replaceable>delta_x</replaceable>,<replaceable>delta_y</replaceable>){<replaceable>num-copies</replaceable>}{<replaceable>obj</replaceable>}
 </screen>
-<para>The <literal>\makebox</literal> command for the picture environment is similar to
-the normal <literal>\makebox</literal> command except that you must specify a
-<replaceable>width</replaceable> and <replaceable>height</replaceable> in multiples of <literal>\unitlength</literal>.
+<para>Copy <replaceable>obj</replaceable> a total of <replaceable>num-copies</replaceable> times, with an increment of
+<replaceable>delta_x,delta_y</replaceable>.  The <replaceable>obj</replaceable> first appears at position
+<inlineequation><mathphrase>(x,y)</mathphrase></inlineequation>, then at <inlineequation><mathphrase>(x+\delta_x,y+\delta_y)</mathphrase></inlineequation>, and so on.
 </para>
-<para>The optional argument, <literal>[<replaceable>position</replaceable>]</literal>, specifies the quadrant that
-your <replaceable>text</replaceable> appears in.  You may select up to two of the following:
+<para>This draws a simple grid with every fifth line in bold (see also
+<link linkend="_005cgraphpaper">\graphpaper</link>).
 </para>
-<variablelist><varlistentry><term><literal>t</literal>
-</term><listitem><para>Moves the item to the top of the rectangle.
-</para>
-</listitem></varlistentry><varlistentry><term><literal>b</literal>
-</term><listitem><para>Moves the item to the bottom.
-</para>
-</listitem></varlistentry><varlistentry><term><literal>l</literal>
-</term><listitem><para>Moves the item to the left.
-</para>
-</listitem></varlistentry><varlistentry><term><literal>r</literal>
-</term><listitem><para>Moves the item to the right.
-</para>
-</listitem></varlistentry></variablelist>
-<para>See <link linkend="_005cmakebox">\makebox</link>.
-</para>
+<screen>\begin{picture}(10,10)
+  \linethickness{0.05mm}
+  \multiput(0,0)(1,0){10}{\line(0,1){10}} 
+  \multiput(0,0)(0,1){10}{\line(1,0){10}}
+  \linethickness{0.5mm}
+  \multiput(0,0)(5,0){3}{\line(0,1){10}}
+  \multiput(0,0)(0,5){3}{\line(1,0){10}}
+\end{picture}
+</screen>
 
 </sect2>
-<sect2 label="8.19.3" id="_005cframebox-_0028picture_0029">
-<title><literal>\framebox</literal></title>
+<sect2 label="8.19.3" id="_005cqbezier">
+<title><literal>\qbezier</literal></title>
 
-<indexterm role="fn"><primary>\framebox</primary></indexterm>
+<indexterm role="fn"><primary>\qbezier</primary></indexterm>
 
 <para>Synopsis:
 </para>
-<screen>\framebox(<replaceable>width</replaceable>,<replaceable>height</replaceable>)[<replaceable>pos</replaceable>]{...}
+<screen>\qbezier(<replaceable>x1</replaceable>,<replaceable>y1</replaceable>)(<replaceable>x2</replaceable>,<replaceable>y2</replaceable>)(<replaceable>x3</replaceable>,<replaceable>y3</replaceable>)
+\qbezier[<replaceable>num</replaceable>](<replaceable>x1</replaceable>,<replaceable>y1</replaceable>)(<replaceable>x2</replaceable>,<replaceable>y2</replaceable>)(<replaceable>x3</replaceable>,<replaceable>y3</replaceable>)
 </screen>
-<para>The <literal>\framebox</literal> command is like <literal>\makebox</literal> (see previous
-section), except that it puts a frame around the outside of the box
-that it creates.
+<para>Draw a quadratic Bezier curve whose control points are given by the
+three required arguments <literal>(<replaceable>x1</replaceable>,<replaceable>y1</replaceable>)</literal>,
+<literal>(<replaceable>x2</replaceable>,<replaceable>y2</replaceable>)</literal>, and <literal>(<replaceable>x3</replaceable>,<replaceable>y3</replaceable>)</literal>.  That is,
+the curve runs from <replaceable>(x1,y1)</replaceable> to <replaceable>(x3,y3)</replaceable>, is quadratic, and is
+such that the tangent line at <replaceable>(x1,y1)</replaceable> passes through
+<replaceable>(x2,y2)</replaceable>, as does the tangent line at <replaceable>(x3,y3)</replaceable>.
 </para>
-<indexterm role="fn"><primary>\fboxrule</primary></indexterm>
-<indexterm role="fn"><primary>\fboxsep</primary></indexterm>
-<para>The <literal>\framebox</literal> command produces a rule of thickness
-<literal>\fboxrule</literal>, and leaves a space <literal>\fboxsep</literal> between the rule
-and the contents of the box.
+<para>This draws a curve from the coordinate (1,1) to (1,0).
 </para>
-
-</sect2>
-<sect2 label="8.19.4" id="_005cdashbox">
-<title><literal>\dashbox</literal></title>
-
-<indexterm role="fn"><primary>\dashbox</primary></indexterm>
-
-<para>Draws a box with a dashed line.  Synopsis:
-</para>
-<screen>\dashbox{<replaceable>dlen</replaceable>}(<replaceable>rwidth</replaceable>,<replaceable>rheight</replaceable>)[<replaceable>pos</replaceable>]{<replaceable>text</replaceable>}
+<screen>\qbezier(1,1)(1.25,0.75)(1,0)  
 </screen>
-<para><literal>\dashbox</literal> creates a dashed rectangle around <replaceable>text</replaceable> in a
-<literal>picture</literal> environment.  Dashes are <replaceable>dlen</replaceable> units long, and the
-rectangle has overall width <replaceable>rwidth</replaceable> and height <replaceable>rheight</replaceable>.
-The <replaceable>text</replaceable> is positioned at optional <replaceable>pos</replaceable>.  <!-- xxref positions. -->
+<para>The curve’s tangent line at (1,1) contains (1.25,0.75), as does the
+curve’s tangent line at (1,0).
 </para>
-<para>A dashed box looks best when the <replaceable>rwidth</replaceable> and <replaceable>rheight</replaceable> are
-multiples of the <replaceable>dlen</replaceable>.
+<para>The optional argument <replaceable>num</replaceable> gives the number of calculated
+intermediate points.  The default is to draw a smooth curve whose
+maximum number of points is <literal>\qbeziermax</literal> (change this value with
+<literal>\renewcommand</literal>).
 </para>
 
 </sect2>
-<sect2 label="8.19.5" id="_005cframe">
-<title><literal>\frame</literal></title>
+<sect2 label="8.19.4" id="_005cgraphpaper">
+<title><literal>\graphpaper</literal></title>
 
-<indexterm role="fn"><primary>\frame</primary></indexterm>
-
+<indexterm role="fn"><primary>\graphpaper</primary></indexterm>
 <para>Synopsis:
 </para>
-<screen>\frame{<replaceable>text</replaceable>}
+<screen>\graphpaper(<replaceable>x_init</replaceable>,<replaceable>y_init</replaceable>)(<replaceable>x_dimen</replaceable>,<replaceable>y_dimen</replaceable>)
+\graphpaper[<replaceable>spacing</replaceable>](<replaceable>x_init</replaceable>,<replaceable>y_init</replaceable>)(<replaceable>x_dimen</replaceable>,<replaceable>y_dimen</replaceable>)
 </screen>
-<para>The <literal>\frame</literal> command puts a rectangular frame around <replaceable>text</replaceable>.
-The reference point is the bottom left corner of the frame.  No extra
-space is put between the frame and the object.
+<para>Draw a coordinate grid.  Requires the <literal>graphpap</literal> package.
+The grid’s origin is <literal>(<replaceable>x_init</replaceable>,<replaceable>y_init</replaceable>)</literal>.
+Grid lines come every <replaceable>spacing</replaceable> units (the default is 10).
+The grid extends <replaceable>x_dimen</replaceable> units to the right and <replaceable>y_dimen</replaceable> units up.
+All arguments must be positive integers.
 </para>
+<para>This make a grid with seven vertical lines and eleven horizontal lines.
+</para>
+<screen>\usepackage{graphpap}    % in preamble
+  ...
+\begin{picture}(6,20)    % in document body
+  \graphpaper[2](0,0)(12,20)
+\end{picture}
+</screen>
+<para>The lines are numbered every ten units.
+</para>
 
 </sect2>
-<sect2 label="8.19.6" id="_005cline">
+<sect2 label="8.19.5" id="_005cline">
 <title><literal>\line</literal></title>
 
 <indexterm role="fn"><primary>\line</primary></indexterm>
 
 <para>Synopsis:
 </para>
-<screen>\line(<replaceable>xslope</replaceable>,<replaceable>yslope</replaceable>){<replaceable>length</replaceable>}
+<screen>\line(<replaceable>x_run</replaceable>,<replaceable>y_rise</replaceable>){<replaceable>travel</replaceable>}
 </screen>
-<para>The <literal>\line</literal> command draws a line with the given <replaceable>length</replaceable> and
-slope <replaceable>xslope</replaceable>/<replaceable>yslope</replaceable>.
+<para>Draw a line.  It slopes such that it vertically rises <replaceable>y_rise</replaceable> for
+every horizontal <replaceable>x_run</replaceable>.  The <replaceable>travel</replaceable> is the total horizontal
+change — it is not the length of the vector, it is the change in
+<inlineequation><mathphrase>x</mathphrase></inlineequation>.  In the special case of vertical lines, where
+(<replaceable>x_run</replaceable>,<replaceable>y_rise</replaceable>)=(0,1), the <replaceable>travel</replaceable> gives the change in
+<inlineequation><mathphrase>y</mathphrase></inlineequation>.
 </para>
+<para>This draws a line starting at coordinates (1,3).
+</para>
+<screen>\put(1,3){\line(2,5){4}}
+</screen>
+<para>For every over 2, this line will go up 5.  Because <replaceable>travel</replaceable>
+specifies that this goes over 4, it must go up 10.  Thus its
+endpoint is <inlineequation><mathphrase>(1,3)+(4,10)=(5,13)</mathphrase></inlineequation>.  In particular, note that
+<inlineequation><mathphrase><replaceable>travel</replaceable>=4</mathphrase></inlineequation> is not the length of the line, it is the change in
+<inlineequation><mathphrase>x</mathphrase></inlineequation>.
+</para>
+<para>The arguments <replaceable>x_run</replaceable> and <replaceable>y_rise</replaceable> are integers that can be
+positive, negative, or zero. (If both are 0 then &latex; treats the
+second as 1.)  With
+<literal>\put(<replaceable>x_init</replaceable>,<replaceable>y_init</replaceable>){\line(<replaceable>x_run</replaceable>,<replaceable>y_rise</replaceable>){<replaceable>travel</replaceable>}}</literal>,
+if <replaceable>x_run</replaceable> is negative then the line’s ending point has a first
+coordinate that is less than <replaceable>x_init</replaceable>.  If <replaceable>y_rise</replaceable> is negative
+then the line’s ending point has a second coordinate that is less than
+<replaceable>y_init</replaceable>.
+</para>
+<para>If <replaceable>travel</replaceable> is negative then you get <literal>LaTeX Error: Bad \line or
+\vector argument.</literal>
+</para>
 <indexterm role="cp"><primary><literal>pict2e</literal> package</primary></indexterm>
 <indexterm role="cp"><primary>graphics packages</primary></indexterm>
-<para>Standard &latex; can only draw lines with <inlineequation><mathphrase><replaceable>slope</replaceable> = x/y</mathphrase></inlineequation>,
-where <inlineequation><mathphrase>x</mathphrase></inlineequation> and <inlineequation><mathphrase>y</mathphrase></inlineequation> have integer values from −6
-through 6.  For lines of any slope, and plenty of other shapes,
-see <literal>pict2e</literal> and many other packages on CTAN.
+<indexterm role="cp"><primary>package, <literal>pict2e</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>pict2e</literal> package</primary></indexterm>
+
+<indexterm role="cp"><primary>package, <literal>TikZ</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>TikZ</literal> package</primary></indexterm>
+
+<indexterm role="cp"><primary>package, <literal>PSTricks</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>PSTricks</literal> package</primary></indexterm>
+
+<indexterm role="cp"><primary>package, <literal>MetaPost</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>MetaPost</literal> package</primary></indexterm>
+
+<indexterm role="cp"><primary>package, <literal>Asymptote</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>Asymptote</literal> package</primary></indexterm>
+
+<para>Standard &latex; can only draw lines with a limited range of slopes
+because these lines are made by putting together line segments from
+pre-made fonts.  The two numbers <replaceable>x_run</replaceable> and <replaceable>y_rise</replaceable> must have
+integer values from −6 through 6.  Also, they must be
+relatively prime, so that <replaceable>(x_run,y_rise)</replaceable> can be (2,1) but not
+(4,2) (if you choose the latter then instead of lines you get sequences
+of arrowheads; the solution is to switch to the former).  To get lines
+of arbitrary slope and plenty of other shapes in a system like
+<literal>picture</literal>, see the package <filename>pict2e</filename> on CTAN.  Another solution
+is to use a full-featured graphics system such as <filename>TikZ</filename>, or
+<filename>PSTricks</filename>, or <filename>MetaPost</filename>, or <filename>Asymptote</filename>
 </para>
 
 </sect2>
-<sect2 label="8.19.7" id="_005clinethickness">
+<sect2 label="8.19.6" id="_005clinethickness">
 <title><literal>\linethickness</literal></title>
 
 <indexterm role="fn"><primary>\linethickness</primary></indexterm>
 
-<para>The <literal>\linethickness{<replaceable>dim</replaceable>}</literal> command declares the thickness
-of horizontal and vertical lines in a picture environment to be
-<replaceable>dim</replaceable>, which must be a positive length.
+<para>Synopsis:
 </para>
-<para><literal>\linethickness</literal> does not affect the thickness of slanted lines,
-circles, or the quarter circles drawn by <literal>\oval</literal>.
+<screen>\linethickness{<replaceable>dim</replaceable>}
+</screen>
+<para>Declares the thickness of subsequent horizontal and vertical lines in a
+picture to be <replaceable>dim</replaceable>, which must be a positive length
+(see <link linkend="Lengths">Lengths</link>).  It differs from <literal>\thinlines</literal> and
+<literal>\thicklines</literal> in that it does not affect the thickness of slanted
+lines, circles, or ovals.
 </para>
 
 </sect2>
-<sect2 label="8.19.8" id="_005cthicklines">
-<title><literal>\thicklines</literal></title>
+<sect2 label="8.19.7" id="_005cthinlines">
+<title><literal>\thinlines</literal></title>
 
-<indexterm role="fn"><primary>\thicklines</primary></indexterm>
+<indexterm role="fn"><primary>\thinlines</primary></indexterm>
 
-<para>The <literal>\thicklines</literal> command is an alternate line thickness for
-horizontal and vertical lines in a picture environment;
-cf. <link linkend="_005clinethickness">\linethickness</link> and <link linkend="_005cthinlines">\thinlines</link>.
+<para>Declaration to set the thickness of subsequent lines, circles, and ovals
+in a picture environment to be 0.4pt.  This is the default
+thickness, so this command is unnecessary unless the thickness has been
+changed with either <link linkend="_005clinethickness">\linethickness</link> or <link linkend="_005cthicklines">\thicklines</link>.
 </para>
 
 </sect2>
-<sect2 label="8.19.9" id="_005cthinlines">
-<title><literal>\thinlines</literal></title>
+<sect2 label="8.19.8" id="_005cthicklines">
+<title><literal>\thicklines</literal></title>
 
-<indexterm role="fn"><primary>\thinlines</primary></indexterm>
+<indexterm role="fn"><primary>\thicklines</primary></indexterm>
 
-<para>The <literal>\thinlines</literal> command is the default line thickness for
-horizontal and vertical lines in a picture environment;
-cf. <link linkend="_005clinethickness">\linethickness</link> and <link linkend="_005cthicklines">\thicklines</link>.
+<para>Declaration to set the thickness of subsequent lines, circles, and ovals
+in a picture environment to be 0.8pt.  See also
+<link linkend="_005clinethickness">\linethickness</link> and <link linkend="_005cthinlines">\thinlines</link>.  This command is illustrated
+in the Trapezoidal Rule example of <link linkend="picture">picture</link>.
 </para>
 
 </sect2>
-<sect2 label="8.19.10" id="_005cmultiput">
-<title><literal>\multiput</literal></title>
+<sect2 label="8.19.9" id="_005ccircle">
+<title><literal>\circle</literal></title>
 
-<indexterm role="fn"><primary>\multiput</primary></indexterm>
+<indexterm role="fn"><primary>\circle</primary></indexterm>
 
 <para>Synopsis:
 </para>
-<screen>\multiput(<replaceable>x</replaceable>,<replaceable>y</replaceable>)(<replaceable>delta_x</replaceable>,<replaceable>delta_y</replaceable>){<replaceable>n</replaceable>}{<replaceable>obj</replaceable>}
+<screen>\circle{<replaceable>diameter</replaceable>}
+\circle*{<replaceable>diameter</replaceable>}
 </screen>
-<para>The <literal>\multiput</literal> command copies the object <replaceable>obj</replaceable> in a regular
-pattern across a picture.  <replaceable>obj</replaceable> is first placed at position
-<inlineequation><mathphrase>(x,y)</mathphrase></inlineequation>, then at <inlineequation><mathphrase>(x+\delta x,y+\delta y)</mathphrase></inlineequation>, and so on,
-<replaceable>n</replaceable> times.
+<para>Produces a circle with a diameter as close as possible to the specified
+one.  The <literal>*</literal> form produces a filled-in circle.
 </para>
+<para>This draws a circle of radius 6, centered at <literal>(5,7)</literal>.
+</para>
+<screen>\put(5,7){\circle{6}}
+</screen>
+<para>The available radii for <literal>circle</literal> are, in points, the even
+numbers from 2 to 20, inclusive.  For <literal>circle*</literal> they are all the
+integers from 1 to 15.
+</para>
 
 </sect2>
-<sect2 label="8.19.11" id="_005coval">
+<sect2 label="8.19.10" id="_005coval">
 <title><literal>\oval</literal></title>
 
 <indexterm role="fn"><primary>\oval</primary></indexterm>
 
 <para>Synopsis:
 </para>
-<screen>\oval(<replaceable>width</replaceable>,<replaceable>height</replaceable>)[<replaceable>portion</replaceable>]
+<screen>\oval(<replaceable>width</replaceable>,<replaceable>height</replaceable>)
+\oval(<replaceable>width</replaceable>,<replaceable>height</replaceable>)[<replaceable>portion</replaceable>]
 </screen>
-<para>The <literal>\oval</literal> command produces a rectangle with rounded corners.  The
-optional argument <replaceable>portion</replaceable> allows you to produce only half of the
-oval via the following:
+<para>Produce a rectangle with rounded corners.  The optional argument
+<replaceable>portion</replaceable> allows you to produce only half or a quarter of the oval.
+For half an oval take <replaceable>portion</replaceable> to be one of these.
 </para>
 <variablelist><varlistentry><term><literal>t</literal>
-</term><listitem><para>selects the top half;
+</term><listitem><para>top half
 </para></listitem></varlistentry><varlistentry><term><literal>b</literal>
-</term><listitem><para>selects the bottom half;
+</term><listitem><para>bottom half
 </para></listitem></varlistentry><varlistentry><term><literal>r</literal>
-</term><listitem><para>selects the right half;
+</term><listitem><para>right half
 </para></listitem></varlistentry><varlistentry><term><literal>l</literal>
-</term><listitem><para>selects the left half.
+</term><listitem><para>left half
 </para></listitem></varlistentry></variablelist>
-<para>It is also possible to produce only one quarter of the oval by setting
-<replaceable>portion</replaceable> to <literal>tr</literal>, <literal>br</literal>, <literal>bl</literal>, or <literal>tl</literal>.
+<para>Produce only one quarter of the oval by setting <replaceable>portion</replaceable> to
+<literal>tr</literal>, <literal>br</literal>, <literal>bl</literal>, or <literal>tl</literal>.
 </para>
-<para>The “corners” of the oval are made with quarter circles with a
-maximum radius of 20pt, so large “ovals” will look more like
-boxes with rounded corners.
+<para>This draws the top half of an oval that is 3 wide and 7 tall.  
 </para>
-
-</sect2>
-<sect2 label="8.19.12" id="_005cput">
-<title><literal>\put</literal></title>
-
-<indexterm role="fn"><primary>\put</primary></indexterm>
-
-<para>Synopsis:
-</para>
-<screen>\put(<replaceable>xcoord</replaceable>,<replaceable>ycoord</replaceable>){ ... }
+<screen>\put(5,7){\oval(3,7)[t]}
 </screen>
-<para>The <literal>\put</literal> command places the material specified by the
-(mandatory) argument in braces at the given coordinate,
-(<replaceable>xcoord</replaceable>,<replaceable>ycoord</replaceable>).
+<para>The (5,7) is the center of the entire oval, not just the center of the
+top half.
 </para>
+<para>These shapes are not ellipses.  They are rectangles whose corners are
+made with quarter circles.  These circles have a maximum radius of
+20pt (see <link linkend="_005ccircle">\circle</link> for the sizes).  Thus large ovals are just
+boxes with a small amount of corner rounding.
+</para>
 
 </sect2>
-<sect2 label="8.19.13" id="_005cshortstack">
+<sect2 label="8.19.11" id="_005cshortstack">
 <title><literal>\shortstack</literal></title>
 
 <indexterm role="fn"><primary>\shortstack</primary></indexterm>
 
 <para>Synopsis:
 </para>
-<screen>\shortstack[<replaceable>position</replaceable>]{...\\...\\...}
+<screen>\shortstack[<replaceable>position</replaceable>]{<replaceable>line 1</replaceable> \\ ... }
 </screen>
-<para>The <literal>\shortstack</literal> command produces a stack of objects.  The valid
-positions are:
+<para>Produce a vertical stack of objects.
 </para>
+<para>This labels the <inlineequation><mathphrase>y</mathphrase></inlineequation> axis.
+</para>
+<screen>\put(0,0){\vector(1,0){4}}   % x axis
+\put(0,0){\vector(0,1){2}}   % y
+\put(-0.25,2){\makebox[0][r]{\shortstack[r]{$y$\\ axis}}}
+</screen>
+<para>For a short stack, the reference point is the lower left of the stack.
+In the above example the <link linkend="_005cmbox-_0026-_005cmakebox">\mbox & \makebox</link> puts the stack flush
+right in a zero width box so in total the short stack sits slightly to
+the left of the <inlineequation><mathphrase>y</mathphrase></inlineequation> axis.
+</para>
+<para>The valid positions are:
+</para>
 <variablelist><varlistentry><term><literal>r</literal>
-</term><listitem><para>Move the objects to the right of the stack.
+</term><listitem><para>Make objects flush right
 </para></listitem></varlistentry><varlistentry><term><literal>l</literal>
-</term><listitem><para>Move the objects to the left of the stack
+</term><listitem><para>Make objects flush left
 </para></listitem></varlistentry><varlistentry><term><literal>c</literal>
-</term><listitem><para>Move the objects to the centre of the stack (default)
+</term><listitem><para>Center objects (default)
 </para></listitem></varlistentry></variablelist>
 <indexterm role="fn"><primary>\\ (for <literal>\shortstack</literal> objects)</primary></indexterm>
-<para>Objects are separated with <literal>\\</literal>.
+<para>Separate objects into lines with <literal>\\</literal>.  These stacks are short in
+that, unlike in a <literal>tabular</literal> or <literal>array</literal> environment, here the
+rows are not spaced out to be of even heights.  Thus, in
+<literal>\shortstack{X\\o\\o\\X}</literal> the first and last rows are taller than
+the middle two.  You can adjust row heights either by putting in the
+usual interline spacing with <literal>\shortstack{X\\ \strut o\\o\\X}</literal>,
+or by hand, via an explicit zero-width box <literal>\shortstack{X \\
+\rule{0pt}{12pt} o\\o\\X}</literal> or by using <literal>\\</literal>’s optional
+argument <literal>\shortstack{X\\[2pt] o\\o\\X}</literal>.
 </para>
+<para>The <literal>\shortstack</literal> command is also available outside the
+<literal>picture</literal> environment.
+</para>
 
 </sect2>
-<sect2 label="8.19.14" id="_005cvector">
+<sect2 label="8.19.12" id="_005cvector">
 <title><literal>\vector</literal></title>
 
 <indexterm role="fn"><primary>\vector</primary></indexterm>
 
 <para>Synopsis:
 </para>
-<screen>\vector(<replaceable>xslope</replaceable>,<replaceable>yslope</replaceable>){<replaceable>length</replaceable>}
+<screen>\vector(<replaceable>x_run</replaceable>,<replaceable>y_rise</replaceable>){<replaceable>travel</replaceable>}
 </screen>
-<para>The <literal>\vector</literal> command draws a line with an arrow of the specified
-length and slope.  The <inlineequation><mathphrase><replaceable>xslope</replaceable></mathphrase></inlineequation> and <inlineequation><mathphrase><replaceable>yslope</replaceable></mathphrase></inlineequation>
-values must lie between −4 and +4, inclusive.
+<para>Draw a line ending in an arrow.  The slope of that line is: it
+vertically rises <replaceable>y_rise</replaceable> for every horizontal <replaceable>x_run</replaceable>.  The
+<replaceable>travel</replaceable> is the total horizontal change — it is not the
+length of the vector, it is the change in <inlineequation><mathphrase>x</mathphrase></inlineequation>.  In the special case
+of vertical vectors, if (<replaceable>x_run</replaceable>,<replaceable>y_rise</replaceable>)=(0,1), then
+<replaceable>travel</replaceable> gives the change in <inlineequation><mathphrase>y</mathphrase></inlineequation>.
 </para>
+<para>For an example see <link linkend="picture">picture</link>.
+</para>
+<para>For elaboration on <replaceable>x_run</replaceable> and <replaceable>y_rise</replaceable> see <link linkend="_005cline">\line</link>.  As
+there, the values of <replaceable>x_run</replaceable> and <replaceable>y_rise</replaceable> are limited.  For
+<literal>\vector</literal> you must chooses integers between −4 and 4,
+inclusive.  Also, the two you choose must be relatively prime.  Thus,
+<literal>\vector(2,1){4}</literal> is acceptable but <literal>\vector(4,2){4}</literal> is
+not (if you use the latter then you get a sequence of arrowheads).
+</para>
 
 </sect2>
+<sect2 label="8.19.13" id="_005cmakebox-_0028picture_0029">
+<title><literal>\makebox</literal> (picture)</title>
+
+<indexterm role="fn"><primary>\makebox (for <literal>picture</literal>)</primary></indexterm>
+
+<para>Synopsis:
+</para>
+<screen>\makebox(<replaceable>rec-width</replaceable>,<replaceable>rec-height</replaceable>){<replaceable>text</replaceable>}
+\makebox(<replaceable>rec-width</replaceable>,<replaceable>rec-height</replaceable>)[<replaceable>position</replaceable>]{<replaceable>text</replaceable>}
+</screen>
+<para>Make a box to hold <replaceable>text</replaceable>.  This command fits with the
+<literal>picture</literal> environment, although you can use it outside of there,
+because <replaceable>rec-width</replaceable> and <replaceable>rec-height</replaceable> are numbers specifying
+distances in terms of the <literal>\unitlength</literal> (see <link linkend="picture">picture</link>).  This
+command is similar to the normal <literal>\makebox</literal> command (see <link linkend="_005cmbox-_0026-_005cmakebox">\mbox &
+\makebox</link>) except here that you must specify the width and height.  This
+command is fragile (see <link linkend="_005cprotect">\protect</link>).
+</para>
+<para>This makes a box of length 3.5 times <literal>\unitlength</literal> and height 4
+times <literal>\unitlength</literal>.
+</para>
+<screen>\put(1,2){\makebox(3.5,4){...}}
+</screen>
+<para>The optional argument <literal><replaceable>position</replaceable></literal> specifies where in the box
+the <replaceable>text</replaceable> appears.  The default is to center it, both horizontally
+and vertically.  To place it somewhere else, use a string with one or
+two of these letters.
+</para>
+<variablelist><varlistentry><term><literal>t</literal>
+</term><listitem><para>Puts <replaceable>text</replaceable> the top of the box.
+</para>
+</listitem></varlistentry><varlistentry><term><literal>b</literal>
+</term><listitem><para>Put <replaceable>text</replaceable> at the bottom.
+</para>
+</listitem></varlistentry><varlistentry><term><literal>l</literal>
+</term><listitem><para>Put <replaceable>text</replaceable> on the left.
+</para>
+</listitem></varlistentry><varlistentry><term><literal>r</literal>
+</term><listitem><para>Put <replaceable>text</replaceable> on the right.
+</para>
+</listitem></varlistentry></variablelist>
+
+</sect2>
+<sect2 label="8.19.14" id="_005cframebox-_0028picture_0029">
+<title><literal>\framebox</literal> (picture)</title>
+
+<indexterm role="fn"><primary>\framebox</primary></indexterm>
+
+<para>Synopsis:
+</para>
+<screen>\framebox(<replaceable>rec-width</replaceable>,<replaceable>rec-height</replaceable>){<replaceable>text</replaceable>}
+\framebox(<replaceable>rec-width</replaceable>,<replaceable>rec-height</replaceable>)[<replaceable>position</replaceable>]{<replaceable>text</replaceable>}
+</screen>
+<para>This is the same as <link linkend="_005cmakebox-_0028picture_0029">\makebox (picture)</link> except that it puts a frame
+around the outside of the box that it creates.  The reference point is
+the bottom left corner of the frame.  This command fits with the
+<literal>picture</literal> environment, although you can use it outside of there,
+because lengths are numbers specifying the distance in terms of the
+<literal>\unitlength</literal> (see <link linkend="picture">picture</link>).  This command is fragile
+(see <link linkend="_005cprotect">\protect</link>).
+</para>
+<para>This example creates a frame 2.5 inches by 3 inches and puts
+the text in the center.
+</para>
+<screen>\setlength{\unitlength}{1in}
+\framebox(2.5,3){test text}
+</screen>
+<para>The required arguments are that the rectangle has overall width
+<replaceable>rect-width</replaceable> units and height <replaceable>rect-height</replaceable> units.
+</para>
+<para>The optional argument <replaceable>position</replaceable> specifies the position of
+<replaceable>text</replaceable>; see <link linkend="_005cmakebox-_0028picture_0029">\makebox (picture)</link> for the values that it can
+take.
+</para>
+<indexterm role="fn"><primary>\fboxrule</primary></indexterm>
+<indexterm role="fn"><primary>\fboxsep</primary></indexterm>
+<para>The rule has thickness <literal>\fboxrule</literal> and there is a blank space
+<literal>\fboxsep</literal> between the frame and the contents of the box.
+</para>
+<para>For this command, you must specify the <replaceable>width</replaceable> and <replaceable>height</replaceable>.  If
+you want to just put a frame around some contents whose dimension is
+determined in some other way then either use <literal>\fbox</literal> (see <link linkend="_005cfbox-_0026-_005cframebox">\fbox
+& \framebox</link>) or <literal>\frame</literal> (see <link linkend="_005cframe">\frame</link>).
+</para>
+
+</sect2>
+<sect2 label="8.19.15" id="_005cframe">
+<title><literal>\frame</literal></title>
+
+<indexterm role="fn"><primary>\frame</primary></indexterm>
+
+<para>Synopsis:
+</para>
+<screen>\frame{<replaceable>contents</replaceable>}
+</screen>
+<para>Puts a rectangular frame around <replaceable>contents</replaceable>.  The reference point is
+the bottom left corner of the frame.  In contrast to <literal>\framebox</literal>
+(see <link linkend="_005cframebox-_0028picture_0029">\framebox (picture)</link>), this command puts no extra space is put
+between the frame and the object.  It is fragile (see <link linkend="_005cprotect">\protect</link>).
+</para>
+
+</sect2>
+<sect2 label="8.19.16" id="_005cdashbox">
+<title><literal>\dashbox</literal></title>
+
+<indexterm role="fn"><primary>\dashbox</primary></indexterm>
+
+<para>Synopsis:
+</para>
+<screen>\dashbox{<replaceable>dash-len</replaceable>}(<replaceable>rect-width</replaceable>,<replaceable>rect-height</replaceable>){<replaceable>text</replaceable>}
+\dashbox{<replaceable>dash-len</replaceable>}(<replaceable>rect-width</replaceable>,<replaceable>rect-height</replaceable>)[<replaceable>position</replaceable>]{<replaceable>text</replaceable>}
+</screen>
+<para>Create a dashed rectangle around <replaceable>text</replaceable>.  This command fits with the
+<literal>picture</literal> environment, although you can use it outside of there,
+because lengths are numbers specifying the distance in terms of the
+<literal>\unitlength</literal> (see <link linkend="picture">picture</link>).
+</para>
+<para>The required arguments are: dashes are <replaceable>dash-len</replaceable> units long, with
+the same length gap, and the rectangle has overall width
+<replaceable>rect-width</replaceable> units and height <replaceable>rect-height</replaceable> units.
+</para>
+<para>The optional argument <replaceable>position</replaceable> specifies the position of
+<replaceable>text</replaceable>; see <link linkend="_005cmakebox-_0028picture_0029">\makebox (picture)</link> for the values that it can
+take.
+</para>
+<para>This shows that you can use non-integer value for <replaceable>dash-len</replaceable>.
+</para>
+<screen>\put(0,0){\dashbox{0.1}(5,0.5){My hovercraft is full of eels.}}
+</screen>
+<para>Each dash will be <literal>0.1\unitlength</literal> long, the box’s width is
+<literal>5\unitlength</literal> and its height is <literal>0.5\unitlength</literal>.
+</para>
+<para>As in that example, a dashed box looks best when <replaceable>rect-width</replaceable> and
+<replaceable>rect-height</replaceable> are multiples of the <replaceable>dash-len</replaceable>.
+</para>
+
+</sect2>
 </sect1>
-<sect1 label="8.20" id="quotation-and-quote">
-<title><literal>quotation</literal> and <literal>quote</literal></title>
+<sect1 label="8.20" id="quotation-_0026-quote">
+<title><literal>quotation</literal> & <literal>quote</literal></title>
 
 <indexterm role="fn"><primary>environment, <literal>quotation</literal></primary></indexterm>
 <indexterm role="fn"><primary><literal>quotation</literal> environment</primary></indexterm>
@@ -4542,35 +5722,28 @@
 <para>Synopsis:
 </para>
 <screen>\begin{quotation}
-<replaceable>text</replaceable>
+  <replaceable>text</replaceable>
 \end{quotation}
 </screen>
 <para>or 
 </para>
 <screen>\begin{quote}
-<replaceable>text</replaceable>
+  <replaceable>text</replaceable>
 \end{quote}
 </screen>
-<para>Include a quotation. 
+<para>Include a quotation. Both environments indent margins on both sides by
+<literal>\leftmargin</literal> and the text is right-justified.
 </para>
-<para>In both environments, margins are indented on both sides by
-<literal>\leftmargin</literal> and the text is justified at both.  As with the main
-text, leaving a blank line produces a new paragraph.
+<para>They differ in how they treat paragraphs. In the <literal>quotation</literal>
+environment, paragraphs are indented by 1.5em and the space
+between paragraphs is small, <literal>0pt plus 1pt</literal>.  In the <literal>quote</literal>
+environment, paragraphs are not indented and there is vertical space
+between paragraphs (it is the rubber length <literal>\parsep</literal>).
 </para>
-<para>To compare the two: in the <literal>quotation</literal> environment, paragraphs are
-indented by 1.5em and the space between paragraphs is small,
-<literal>0pt plus 1pt</literal>.  In the <literal>quote</literal> environment, paragraphs are
-not indented and there is vertical space between paragraphs (it is the
-rubber length <literal>\parsep</literal>).  Thus, the <literal>quotation</literal> environment
-may be more suitable for documents where new paragraphs are marked by an
-indent rather than by a vertical separation.  In addition, <literal>quote</literal>
-may be more suitable for a short quotation or a sequence of short
-quotations.
-</para>
-<screen>\begin{quotation}
-\it Four score and seven years ago
+<screen>\begin{quotation} \small\it
+  Four score and seven years ago
   ... shall not perish from the earth.
-\hspace{1em plus 1fill}---Abraham Lincoln
+  \hspace{1em plus 1fill}---Abraham Lincoln
 \end{quotation}
 </screen>
 
@@ -4593,10 +5766,11 @@
 ...
 \end{tabbing}
 </screen>
-<para>The <literal>tabbing</literal> environment aligns text in columns.  It works by
-setting tab stops and tabbing to them much as was done on a typewriter.
-It is best suited for cases where the width of each column is constant
-and known in advance.
+<para>Align text in columns, by setting tab stops and tabbing to them much as
+was done on a typewriter.  This is less often used than the environments
+<literal>tabular</literal> (see <link linkend="tabular">tabular</link>) or <literal>array</literal> (see <link linkend="array">array</link>) because
+in those the width of each column need not be constant and need not be
+known in advance.
 </para>
 <para>This example has a first line where the tab stops are set to explicit
 widths, ended by a <literal>\kill</literal> command (which is described below):
@@ -4727,8 +5901,9 @@
             end;\\
 \end{tabbing}
 </screen>
-<para>The output looks like this:
-</para><screen>function fact(n : integer) : integer;
+<para>The output looks like this.
+</para>
+<screen>function fact(n : integer) : integer;
          begin
                if n > 1 then
                   fact := n * fact(n-1);
@@ -4746,13 +5921,11 @@
 <indexterm role="cp"><primary>package, <literal>fancyvrb</literal></primary></indexterm>
 <indexterm role="cp"><primary><literal>fancyvrb</literal> package</primary></indexterm>
 
-
-<para>(The above example is just for illustration of the environment.  To
-actually typeset computer code in typewriter like this, a verbatim
-environment (see <link linkend="verbatim">verbatim</link>) would normally suffice.  For
-pretty-printed code, there are quite a few packages, including
-<literal>algorithm2e</literal>, <literal>fancyvrb</literal>, <literal>listings</literal>, and
-<literal>minted</literal>.)
+<para>This example is just for illustration of the environment.  To actually
+typeset computer code in typewriter like this, a verbatim environment
+(see <link linkend="verbatim">verbatim</link>) would normally be best.  For pretty-printed code,
+there are quite a few packages, including <literal>algorithm2e</literal>,
+<literal>fancyvrb</literal>, <literal>listings</literal>, and <literal>minted</literal>.
 </para>
         
 </sect1>
@@ -4768,29 +5941,46 @@
 <para>Synopsis:
 </para>
 <screen>\begin{table}[<replaceable>placement</replaceable>]
-  table body
-\caption[<replaceable>loftitle</replaceable>]{<replaceable>title</replaceable>}
-\label{<replaceable>label}</replaceable>
+  <replaceable>table body</replaceable>
+  \caption[<replaceable>loftitle</replaceable>]{<replaceable>title</replaceable>}  % optional
+  \label{<replaceable>label}</replaceable>              % also optional
 \end{table}
 </screen>
-<para>A class of floats (see <link linkend="Floats">Floats</link>).  Because they cannot be split across
-pages, they are not typeset in sequence with the normal text but instead
-are “floated” to a convenient place, such as the top of a following
-page.
+<para>A class of floats (see <link linkend="Floats">Floats</link>).  They cannot be split across pages
+and so they are not typeset in sequence with the normal text but instead
+are floated to a convenient place, such as the top of a following page.
 </para>
+<para>This example <literal>table</literal> environment contains a <literal>tabular</literal>
+</para>
+<screen>\begin{table}
+  \centering\small
+  \begin{tabular}{ll}
+    \multicolumn{1}{c}{\textit{Author}}
+      &\multicolumn{1}{c}{\textit{Piece}}  \\ \hline
+    Bach            &Cello Suite Number 1  \\
+    Beethoven       &Cello Sonata Number 3 \\
+    Brahms          &Cello Sonata Number 1
+  \end{tabular}
+  \caption{Top cello pieces}
+  \label{tab:cello}
+\end{table}
+</screen>
+<para>but you can put many different kinds of content in a <literal>table</literal>,
+including text, &latex; commands, etc.
+</para>
 <para>For the possible values of <replaceable>placement</replaceable> and their effect on the 
 float placement algorithm, see <link linkend="Floats">Floats</link>.
 </para>
-<para>The table body is typeset in a <literal>parbox</literal> of width <literal>\textwidth</literal>
-and so it can contain text, commands, etc.
+<para>The table body is typeset in a <literal>parbox</literal> of width <literal>\textwidth</literal>.
+It can contain text, commands, graphics, etc.
 </para>
 <para>The label is optional; it is used for cross references (see <link linkend="Cross-references">Cross
 references</link>).  
 <indexterm role="fn"><primary>\caption</primary></indexterm>
-The optional <literal>\caption</literal> command specifies caption text for the
-table.  By default it is numbered.  If <replaceable>lottitle</replaceable> is present, it is
-used in the list of tables instead of <replaceable>title</replaceable> (see <link linkend="Tables-of-contents">Tables of
-contents</link>).
+The <literal>\caption</literal> command is also optional.  It specifies caption text
+for the table.  By default it is numbered.  If its optional
+<replaceable>lottitle</replaceable> is present then that text is used in the list of tables
+instead of <replaceable>title</replaceable> (see <link linkend="Table-of-contents-etc_002e">Table of contents etc.</link>).
 </para>
 <para>In this example the table and caption will float to the bottom of a page,
 unless it is pushed to a float page at the end.
@@ -4820,20 +6010,20 @@
 <para>Synopsis:
 </para>
 <screen>\begin{tabular}[<replaceable>pos</replaceable>]{<replaceable>cols</replaceable>}
-column 1 entry &column 2 entry ... &column n entry \\
+  <replaceable>column 1 entry</replaceable>  &<replaceable>column 2 entry</replaceable>  ...  &<replaceable>column n entry</replaceable> \\
   ...
 \end{tabular}
 </screen>
 <para>or
 </para>
 <screen>\begin{tabular*}{<replaceable>width</replaceable>}[<replaceable>pos</replaceable>]{<replaceable>cols</replaceable>}
-column 1 entry &column 2 entry ... &column n entry \\
+  <replaceable>column 1 entry</replaceable>  &<replaceable>column 2 entry</replaceable>  ...  &<replaceable>column n entry</replaceable> \\
   ...
 \end{tabular*}
 </screen>
-<para>These environments produce a table, a box consisting of a sequence of
-horizontal rows.  Each row consists of items that are aligned vertically
-in columns.  This illustrates many of the features.
+<para>Produce a table, a box consisting of a sequence of horizontal rows.
+Each row consists of items that are aligned vertically in columns.  This
+illustrates many of the features.
 </para>
 <screen>\begin{tabular}{l|l}
   \textit{Player name}  &\textit{Career home runs}  \\ 
@@ -4842,27 +6032,21 @@
   Babe Ruth   &714
 \end{tabular}
 </screen>
-<para>The vertical format of two left-aligned columns, with a vertical bar
-between them, is specified in <literal>tabular</literal>’s argument <literal>{l|l}</literal>.
+<para>The output will have two left-aligned columns with a vertical bar
+between them.  This is specified in <literal>tabular</literal>’s argument
+<literal>{l|l}</literal>.
 <indexterm role="fn"><primary>&</primary></indexterm>
-Columns are separated with an ampersand <literal>&</literal>.  A horizontal rule
-between two rows is created with <literal>\hline</literal>.
+Put the entries into different columns by separating them with an
+ampersand, <literal>&</literal>.  The end of each row is marked with a double
+backslash, <literal>\\</literal>.  Put a horizontal rule below a row, after a double
+backslash, with <literal>\hline</literal>.
 <indexterm role="fn"><primary>\\ for <literal>tabular</literal></primary></indexterm>
-The end of each row is marked with a double backslash <literal>\\</literal>.
 This <literal>\\</literal> is optional after the last row unless an <literal>\hline</literal>
 command follows, to put a rule below the table.
 </para>
 <para>The required and optional arguments to <literal>tabular</literal> consist of:
 </para>
-<variablelist><varlistentry><term><replaceable>width</replaceable>
-</term><listitem><para>Required for <literal>tabular*</literal>, not allowed for <literal>tabular</literal>. Specifies
-the width of the <literal>tabular*</literal> environment.  The space between columns
-should be rubber, as with <literal>@{\extracolsep{\fill}}</literal>, to allow
-the table to stretch or shrink to make the specified width, or else you
-are likely to get the <literal>Underfull \hbox (badness 10000) in alignment
-...</literal> warning.
-</para>
-</listitem></varlistentry><varlistentry><term><replaceable>pos</replaceable>
+<variablelist><varlistentry><term><replaceable>pos</replaceable>
 </term><listitem><para>Optional.  Specifies the table’s vertical position.  The default is to
 align the table so its vertical center matches the baseline of the
 surrounding text.  There are two other possible alignments: <literal>t</literal>
@@ -4891,25 +6075,28 @@
 </term><listitem><para>A vertical line the full height and depth of the environment.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>@{<replaceable>text or space</replaceable>}</literal>
-</term><listitem><para>This inserts <replaceable>text or space</replaceable> at this location in every row.  The
-<replaceable>text or space</replaceable> material is typeset in LR mode.  This text is
-fragile (see <link linkend="_005cprotect">\protect</link>).
+</term><listitem><para>Insert <replaceable>text or space</replaceable> at this location in every row.  The <replaceable>text
+or space</replaceable> material is typeset in LR mode.  This text is fragile
+(see <link linkend="_005cprotect">\protect</link>).
 </para>
-<para>This specifier is optional: with no @-expression, &latex;’s
+<para>If between two columns there is no @-expression then &latex;’s
 <literal>book</literal>, <literal>article</literal>, and <literal>report</literal> classes will put on
-either side of each column a space of length <literal>\tabcolsep</literal>, which
-by default is ‘<literal>6pt</literal>’.  That is, by default adjacent columns are
-separated by 12pt (so <literal>\tabcolsep</literal> is misleadingly-named since it
-is not the separation between tabular columns).  By implication, a
-space of 6pt also comes before the first column and after the final
-column, unless you put a <literal>@{...}</literal> or <literal>|</literal> there.
+either side of each column a space of length <literal>\tabcolsep</literal>, which by
+default is 6pt.  That is, by default adjacent columns are
+separated by 12pt (so <literal>\tabcolsep</literal> is misleadingly named
+since it is only half of the separation between tabular columns).  In
+addition, a space of 6pt also comes before the first column and
+after the final column, unless you put a <literal>@{...}</literal> or <literal>|</literal>
+there.
 </para>
-<para>If you override the default and use an @-expression then you must
-insert any desired space yourself, as in <literal>@{\hspace{1em}}</literal>.
+<para>If you override the default and use an @-expression then &latex; does
+not insert <literal>\tabcolsep</literal> so you must insert any desired space
+yourself, as in <literal>@{\hspace{1em}}</literal>.
 </para>
-<para>An empty expression <literal>@{}</literal> will eliminate the space, including
-the space at the start or end, as in the example below where the tabular
-lines need to lie on the left margin.
+<para>An empty expression <literal>@{}</literal> will eliminate the space.  In
+particular, sometimes you want to eliminate the the space before the
+first column or after the last one, as in the example below where the
+tabular lines need to lie on the left margin.
 </para>
 <screen>\begin{flushleft}
   \begin{tabular}{@{}l}
@@ -4917,8 +6104,8 @@
   \end{tabular}
 \end{flushleft}
 </screen>
-<para>This example shows text, a decimal point, between the columns, arranged
-so the numbers in the table are aligned on that decimal point.
+<para>The next example shows text, a decimal point between the columns,
+arranged so the numbers in the table are aligned on it.
 </para>
 <screen>\begin{tabular}{r@{$.$}l}
   $3$ &$14$  \\
@@ -4928,19 +6115,17 @@
 <indexterm role="fn"><primary>\extracolsep</primary></indexterm>
 <para>An <literal>\extracolsep{<replaceable>wd</replaceable>}</literal> command in an @-expression causes an
 extra space of width <replaceable>wd</replaceable> to appear to the left of all subsequent
-columns, until countermanded by another <literal>\extracolsep</literal> command.
-Unlike ordinary intercolumn space, this extra space is not suppressed by
-an @-expression.  An <literal>\extracolsep</literal> command can be used only in an
+columns, until countermanded by another <literal>\extracolsep</literal>.  Unlike
+ordinary intercolumn space, this extra space is not suppressed by an
+ at -expression.  An <literal>\extracolsep</literal> command can be used only in an
 @-expression in the <literal>cols</literal> argument.  Below, &latex; inserts the
 right amount of intercolumn space to make the entire table 4 inches
 wide.
 </para>
-<screen>\begin{center}
-  \begin{tabular*}{4in}{l@{\ \ldots\extracolsep{\fill}}l}
-    Seven times down, eight times up 
-    &such is life!
-  \end{tabular*}
-\end{center}
+<screen>\begin{tabular*}{4in}{l@{\extracolsep{\fill}}l}
+  Seven times down, eight times up \ldots 
+  &such is life!
+\end{tabular*}
 </screen>
 <para>To insert commands that are automatically executed before a given
 column, load the <literal>array</literal> package and use the <literal>>{...}</literal>
@@ -4948,45 +6133,56 @@
 <!-- xx should fully explain array, tabularx, and all other base packages... -->
 </para>
 </listitem></varlistentry><varlistentry><term><literal>p{<replaceable>wd</replaceable>}</literal>
-</term><listitem><para>Each item in the column is typeset in a parbox of width <replaceable>wd</replaceable>.
+</term><listitem><para>Each item in the column is typeset in a parbox of width <replaceable>wd</replaceable>, as if
+it were the argument of a <literal>\parbox[t]{wd}{...}</literal> command.
 </para>
-<para>Note that a line break double backslash <literal>\\</literal> may not appear in the
-item, except inside an environment like <literal>minipage</literal>, <literal>array</literal>,
-or <literal>tabular</literal>, or inside an explicit <literal>\parbox</literal>, or in the scope
-of a <literal>\centering</literal>, <literal>\raggedright</literal>, or <literal>\raggedleft</literal>
+<para>A line break double backslash <literal>\\</literal> may not appear in the item,
+except inside an environment like <literal>minipage</literal>, <literal>array</literal>, or
+<literal>tabular</literal>, or inside an explicit <literal>\parbox</literal>, or in the scope of
+a <literal>\centering</literal>, <literal>\raggedright</literal>, or <literal>\raggedleft</literal>
 declaration (when used in a <literal>p</literal>-column element these declarations
 must appear inside braces, as with <literal>{\centering .. \\
 ..}</literal>). Otherwise &latex; will misinterpret the double backslash as
-ending the row.
+ending the row.  Instead, to get a line break in there use
+<literal>\newline</literal> (see <link linkend="_005cnewline">\newline</link>).
 </para>
 </listitem></varlistentry><varlistentry><term><literal>*{<replaceable>num</replaceable>}{<replaceable>cols</replaceable>}</literal>
 </term><listitem><para>Equivalent to <replaceable>num</replaceable> copies of <replaceable>cols</replaceable>, where <replaceable>num</replaceable> is a
-positive integer and <replaceable>cols</replaceable> is a list of specifiers.  Thus
-<literal>\begin{tabular}{|*{3}{l|r}|}</literal> is equivalent to
-<literal>\begin{tabular}{|l|rl|rl|r|}</literal>.  Note that <replaceable>cols</replaceable> may
-contain another <literal>*</literal>-expression.
+positive integer and <replaceable>cols</replaceable> is a list of specifiers.  Thus the
+specifier <literal>\begin{tabular}{|*{3}{l|r}|}</literal> is equivalent to
+the specifier <literal>\begin{tabular}{|l|rl|rl|r|}</literal>.  Note that
+<replaceable>cols</replaceable> may contain another <literal>*</literal>-expression.
 </para> 
-</listitem></varlistentry></variablelist></listitem></varlistentry></variablelist>
+</listitem></varlistentry></variablelist>
+</listitem></varlistentry><varlistentry><term><replaceable>width</replaceable>
+</term><listitem><para>Required for <literal>tabular*</literal>, not allowed for <literal>tabular</literal>. Specifies
+the width of the <literal>tabular*</literal> environment.  The space between columns
+should be rubber, as with <literal>@{\extracolsep{\fill}}</literal>, to allow
+the table to stretch or shrink to make the specified width, or else you
+are likely to get the <literal>Underfull \hbox (badness 10000) in alignment
+...</literal> warning.
+</para>
+</listitem></varlistentry></variablelist>
 <para>Parameters that control formatting:
 <!-- xx defaults, own node (xref from array)? -->
 </para>
 <variablelist><varlistentry><term><indexterm role="fn"><primary>\arrayrulewidth</primary></indexterm><literal>\arrayrulewidth</literal>
-</term><listitem><para>A length that is the thickness of the rule created by <literal>|</literal>,
+</term><listitem><anchor id="tabular-arrayrulewidth"/><para>A length that is the thickness of the rule created by <literal>|</literal>,
 <literal>\hline</literal>, and <literal>\vline</literal> in the <literal>tabular</literal> and <literal>array</literal>
 environments.  The default is ‘<literal>.4pt</literal>’. Change it as in
 <literal>\setlength{\arrayrulewidth}{0.8pt}</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\arraystretch</primary></indexterm><literal>\arraystretch</literal>
-</term><listitem><para>A factor by which the spacing between rows in the <literal>tabular</literal> and
+</term><listitem><anchor id="tabular-arraystrech"/><para>A factor by which the spacing between rows in the <literal>tabular</literal> and
 <literal>array</literal> environments is multiplied.  The default is ‘<literal>1</literal>’, for
 no scaling.  Change it as <literal>\renewcommand{\arraystretch}{1.2}</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\doublerulesep</primary></indexterm><literal>\doublerulesep</literal>
-</term><listitem><para>A length that is the distance between the vertical rules produced by the
+</term><listitem><anchor id="tabular-doublerulesep"/><para>A length that is the distance between the vertical rules produced by the
 <literal>||</literal> specifier.  The default is ‘<literal>2pt</literal>’.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\tabcolsep</primary></indexterm><literal>\tabcolsep</literal>
-</term><listitem><para>A length that is half of the space between columns. The default is
+</term><listitem><anchor id="tabular-tabcolsep"/><para>A length that is half of the space between columns. The default is
 ‘<literal>6pt</literal>’.  Change it with <literal>\setlength</literal>.
 </para>
 </listitem></varlistentry></variablelist>
@@ -5016,8 +6212,9 @@
 spanned by the single heading ‘<literal>Name</literal>’.
 </para>
 <screen>\begin{tabular}{lccl} 
-  \textit{ID}       &\multicolumn{2}{c}{\textit{Name}} &\textit{Age} \\ \hline % row one 
-  978-0-393-03701-2 &O'Brian &Patrick                  &55           \\        % row two 
+  \textit{ID}       &\multicolumn{2}{c}{\textit{Name}} &\textit{Age} \\
+  \hline  
+  978-0-393-03701-2 &O'Brian &Patrick                  &55           \\
     ...
 \end{tabular}
 </screen>
@@ -5095,23 +6292,23 @@
 bar <literal>|</literal> is more common.  This command is rarely used in the
 body of a table; typically a table’s vertical lines are specified in
 <literal>tabular</literal>’s <replaceable>cols</replaceable> argument and overridden as needed with
-<literal>\multicolumn</literal>.
+<literal>\multicolumn</literal> (see <link linkend="tabular">tabular</link>).
 </para>
-<para>This example illustrates some pitfalls.  In the first line’s second
+<para>The example below illustrates some pitfalls.  In the first row’s second
 entry the <literal>\hfill</literal> moves the <literal>\vline</literal> to the left edge of the
 cell.  But that is different than putting it halfway between the two
-columns, so in that row between the first and second columns there are
-two vertical rules, with the one from the <literal>{c|cc}</literal> specifier
-coming before the one produced by the <literal>\vline\hfill</literal>.  In contrast,
-the first line’s third entry shows the usual way to put a vertical bar
-between two columns.  In the second line, the <literal>ghi</literal> is the widest
-entry in its column so in the <literal>\vline\hfill</literal> the <literal>\hfill</literal> has
-no effect and the vertical line in that entry appears immediately next
-to the <literal>g</literal>, with no whitespace.
+columns, so between the first and second columns there are two vertical
+rules, with the one from the <literal>{c|cc}</literal> specifier coming before the
+one produced by the <literal>\vline\hfill</literal>.  In contrast, the first row’s
+third entry shows the usual way to put a vertical bar between two
+columns.  In the second row, the <literal>ghi</literal> is the widest entry in its
+column so in the <literal>\vline\hfill</literal> the <literal>\hfill</literal> has no effect and
+the vertical line in that entry appears immediately next to the
+<literal>g</literal>, with no whitespace.
 </para>
 <screen>\begin{tabular}{c|cc}
-  x   &\vline\hfill y   &\multicolumn{1}{|r}{z} \\  
-  abc &def &\vline\hfill ghi 
+  x   &\vline\hfill y   &\multicolumn{1}{|r}{z} \\ % row 1  
+  abc &def &\vline\hfill ghi                       % row 2  
 \end{tabular}
 </screen>
 
@@ -5125,10 +6322,10 @@
 </para>
 <screen>\cline{<replaceable>i</replaceable>-<replaceable>j</replaceable>}
 </screen>
-<para>Draw a horizontal rule in an <literal>array</literal> or <literal>tabular</literal> environment
-beginning in column <replaceable>i</replaceable> and ending in column <replaceable>j</replaceable>. The
-dash <literal>-</literal> must appear in the mandatory argument. To span a
-single column use the number twice.
+<para>In an <literal>array</literal> or <literal>tabular</literal> environment, draw a horizontal rule
+beginning in column <replaceable>i</replaceable> and ending in column <replaceable>j</replaceable>. The
+dash, <literal>-</literal>, must appear in the mandatory argument. To span a single
+column use the number twice, as with <literal>\cline{2-2}</literal>.
 </para>
 <para>This example puts two horizontal lines between the first and second
 rows, one line in the first column only, and the other spanning the
@@ -5147,7 +6344,7 @@
 
 <indexterm role="fn"><primary>\hline</primary></indexterm>
 
-<para>Draws a horizontal line the width of the enclosing <literal>tabular</literal> or
+<para>Draw a horizontal line the width of the enclosing <literal>tabular</literal> or
 <literal>array</literal> environment.  It’s most commonly used to draw a line at the
 top, bottom, and between the rows of a table.
 </para>
@@ -5176,42 +6373,58 @@
 <para>Synopsis:
 </para>
 <screen>\begin{thebibliography}{<replaceable>widest-label</replaceable>}
-\bibitem[<replaceable>label</replaceable>]{<replaceable>cite_key}</replaceable>
-...
+  \bibitem[<replaceable>label</replaceable>]{<replaceable>cite_key}</replaceable>
+  ...
 \end{thebibliography}
 </screen>
-<para>The <literal>thebibliography</literal> environment produces a bibliography or
-reference list.
+<para>Produce a bibliography or reference list.  There are two ways to produce
+bibliographic lists.  This environment is suitable when you have only a
+few references and can maintain the list by hand.  See <link linkend="Using-BibTeX">Using BibTeX</link>
+for a more sophisticated approach.
 </para>
-<para>In the <literal>article</literal> class, this reference list is labelled
-‘<literal>References</literal>’ and the label is stored in macro <literal>\refname</literal>; in
-the <literal>report</literal> class, it is labelled ‘<literal>Bibliography</literal>’ and the
-label is stored in macro <literal>\bibname</literal>.
+<para>This shows the environment with two entries.
 </para>
-<para>You can change the label by redefining the command <literal>\refname</literal> or
-<literal>\bibname</literal>, whichever is applicable depending on the class:
+<screen>This work is based on \cite{latexdps}.
+Together they are \cite{latexdps, texbook}.
+  ...
+\begin{thebibliography}{9}
+\bibitem{latexdps} 
+  Leslie Lamport. 
+  \textit{\LaTeX{}: a document preparation system}. 
+  Addison-Wesley, Reading, Massachusetts, 1993.
+\bibitem{texbook} 
+  Donald Ervin Knuth. 
+  \textit{The \TeX book}. 
+  Addison-Wesley, Reading, Massachusetts, 1983.
+\end{thebibliography}
+</screen>
+<para>This styles the first reference as ‘<literal>[1] Leslie ...</literal>’, and so that
+<literal>\cite{latexdps}</literal> produces the matching ‘<literal>... based on [1]</literal>’.
+The second <literal>\cite</literal> produces ‘<literal>[1, 2]</literal>’.  You must compile the
+document twice to resolve these references.
 </para>
-<itemizedlist><listitem><indexterm role="fn"><primary>\bibname</primary></indexterm>
-<para>For standard classes whose top level sectioning is <literal>\chapter</literal>
-(such as <filename>book</filename> and <filename>report</filename>), the label is in the macro
-<literal>\bibname</literal>;
+<para>The mandatory argument <replaceable>widest-label</replaceable> is text that, when typeset, is
+as wide as the widest item label produced by the <literal>\bibitem</literal>
+commands.  The tradition is to use <literal>9</literal> for bibliographies with less
+than 10 references, <literal>99</literal> for ones with less than 100, etc.
 </para>
-</listitem><listitem><indexterm role="fn"><primary>\refname</primary></indexterm>
-<para>For standard classes whose the top level sectioning is <literal>\section</literal>
-(such as <filename>article</filename>), the label is in macro <literal>\refname</literal>.
-</para></listitem></itemizedlist>
+<para>The bibliographic list is headed by a title such as ‘<literal>Bibliography</literal>’.
+To change it there are two cases.  In the <filename>book</filename> and <filename>report</filename>
+classes, where the top level sectioning is <literal>\chapter</literal> and the
+default title is ‘<literal>Bibliography</literal>’, that title is in the macro
+<literal>\bibname</literal>.  For <filename>article</filename>, where the class’s top level
+sectioning is <literal>\section</literal> and the default is ‘<literal>References</literal>’, the
+title is in macro <literal>\refname</literal>.  Change it by redefining the command,
+as with <literal>\renewcommand{\refname}{Cited references}</literal> after
+<literal>\begin{document}</literal>.
+</para>
 <indexterm role="cp"><primary>package, <literal>babel</literal></primary></indexterm>
 <indexterm role="cp"><primary><literal>babel</literal> package</primary></indexterm>
 
-<para>Typically it is neither necessary nor desirable to directly redefine
-<literal>\refname</literal> or <literal>\bibname</literal>; language support packages like
-<filename>babel</filename> do this.
+<para>Language support packages such as <filename>babel</filename> will automatically
+redefine <literal>\refname</literal> or <literal>\bibname</literal> to fit the selected
+language.
 </para>
-<para>The mandatory <replaceable>widest-label</replaceable> argument is text that, when typeset,
-is as wide as the widest item label produced by the <literal>\bibitem</literal>
-commands.  It is typically given as <literal>9</literal> for bibliographies with
-less than 10 references, <literal>99</literal> for ones with less than 100, etc.
-</para>
 
 
 <sect2 label="8.24.1" id="_005cbibitem">
@@ -5221,22 +6434,63 @@
 
 <para>Synopsis:
 </para>
+<screen>\bibitem{<replaceable>cite_key</replaceable>}
+</screen>
+<para>or
+</para>
 <screen>\bibitem[<replaceable>label</replaceable>]{<replaceable>cite_key</replaceable>}
 </screen>
-<para>The <literal>\bibitem</literal> command generates an entry labelled by <replaceable>label</replaceable>.
-If the <replaceable>label</replaceable> argument is missing, a number is automatically
-generated using the <literal>enumi</literal> counter.  The <replaceable>cite_key</replaceable> is a
+<para>Generate an entry labeled by <replaceable>label</replaceable>.  The default is for &latex; to
+generates a number using the <literal>enumi</literal> counter.  The <firstterm>citation key</firstterm> 
 <indexterm role="cp"><primary>citation key</primary></indexterm>
-<firstterm>citation key</firstterm> consisting in any sequence of
-letters, numbers, and punctuation symbols not containing a comma.
+<replaceable>cite_key</replaceable> is a string of
+letters, numbers, and punctuation symbols (but not comma).
 </para>
-<para>This command writes an entry to the <filename>.aux</filename> file containing the
-item’s <replaceable>cite_key</replaceable> and <replaceable>label</replaceable>.  When the <filename>.aux</filename> file is
-read by the <literal>\begin{document}</literal> command, the item’s <replaceable>label</replaceable> is
-associated with <literal>cite_key</literal>, causing references to <replaceable>cite_key</replaceable>
-with a <literal>\cite</literal> command (see <link linkend="_005ccite">\cite</link>) to produce the associated
-<replaceable>label</replaceable>.
+<para>See <link linkend="thebibliography">thebibliography</link> for an example.
 </para>
+<para>The optional <replaceable>label</replaceable> changes the default label from an integer to the
+given string.  With this
+</para>
+<screen>\begin{thebibliography}
+\bibitem[Lamport 1993]{latexdps} 
+  Leslie Lamport. 
+  \textit{\LaTeX{}: a document preparation system}. 
+  Addison-Wesley, Reading, Massachusetts, 1993.
+\bibitem{texbook} 
+  Donald Ervin Knuth. 
+  \textit{The \TeX book}. 
+  Addison-Wesley, Reading, Massachusetts, 1983.
+\end{thebibliography}
+</screen>
+<para>the first entry will be styled as ‘<literal>[Lamport 1993] Leslie ...</literal>’  (The
+amount of horizontal space that &latex; leaves for the label depends on
+the <replaceable>widest-label</replaceable> argument of the <literal>thebibliography</literal>
+environment; see <link linkend="thebibliography">thebibliography</link>.)  Similarly, <literal>... based on
+\cite{latexdps}</literal> will produce ‘<literal>... based on [Lamport 1994]</literal>’.
+</para>
+<para>If you mix <literal>\bibitem</literal> entries having a <replaceable>label</replaceable> with those that
+do not then &latex; will number the unlabelled ones sequentially.  In
+the example above the <literal>texbook</literal> entry will appear as ‘<literal>[1]
+Donald ...</literal>’, despite that it is the second entry.
+</para>
+<para>If you use the same <replaceable>cite_key</replaceable> twice then you get ‘<literal>LaTeX
+Warning: There were multiply-defined labels</literal>’.
+</para>
+<para>Under the hood, &latex; remembers the <replaceable>cite_key</replaceable> and <replaceable>label</replaceable>
+information because <literal>\bibitem</literal> writes it to the auxiliary file
+<filename><replaceable>filename</replaceable>.aux</filename>.  For instance, the above example causes
+<literal>\bibcite{latexdps}{Lamport, 1993}</literal> and
+<literal>\bibcite{texbook}{1}</literal> to appear in that file.  The <filename>.aux</filename>
+file is read by the <literal>\begin{document}</literal> command and then the
+information is available for <literal>\cite</literal> commands.  This explains why
+you need to run &latex; twice to resolve references: once to write it
+out and once to read it in.
+</para>
+<para>Because of this two-pass algorithm, when you add a <literal>\bibitem</literal> or
+change its <replaceable>cite_key</replaceable> you may get ‘<literal>LaTeX Warning: Label(s) may
+have changed. Rerun to get cross-references right</literal>’.  Fix it by
+recompiling.
+</para>
 
 </sect2>
 <sect2 label="8.24.2" id="_005ccite">
@@ -5246,17 +6500,49 @@
 
 <para>Synopsis:
 </para>
+<screen>\cite{<replaceable>keys</replaceable>}
+</screen>
+<para>or
+</para>
 <screen>\cite[<replaceable>subcite</replaceable>]{<replaceable>keys</replaceable>}
 </screen>
-<para>The <replaceable>keys</replaceable> argument is a list of one or more citation keys
-(see <link linkend="_005cbibitem">\bibitem</link>), separated by commas.  This command generates an
-in-text citation to the references associated with <replaceable>keys</replaceable> by entries
-in the <filename>.aux</filename> file.
+<para>Generate as output a citation to the references associated with
+<replaceable>keys</replaceable>.  The mandatory <replaceable>keys</replaceable> is a citation key, or a
+comma-separated list of citation keys (see <link linkend="_005cbibitem">\bibitem</link>).
 </para>
-<para>The text of the optional <replaceable>subcite</replaceable> argument appears after the
-citation.  For example, <literal>\cite[p.~314]{knuth}</literal> might produce
-‘<literal>[Knuth, p. 314]</literal>’.
+<para>This 
 </para>
+<screen>The ultimate source is \cite{texbook}.
+  ...
+\begin{thebibliography}
+\bibitem{texbook} 
+  Donald Ervin Knuth. 
+  \textit{The \TeX book}. 
+  Addison-Wesley, Reading, Massachusetts, 1983.
+\end{thebibliography}
+</screen>
+<para>produces the output ‘<literal>... source is [1]</literal>’.
+</para>
+<para>The optional argument <replaceable>subcite</replaceable> is appended to the citation.  For
+example, <literal>See 14.3 in \cite[p.~314]{texbook}</literal> might produce
+‘<literal>See 14.3 in [1, p. 314]</literal>’.
+</para>
+<para>If <replaceable>keys</replaceable> is not in your bibliography information then you get
+‘<literal>LaTeX Warning: There were undefined references</literal>’, and in the output
+the citation shows as a boldface question mark between square brackets.
+There are two possible causes.  If you have mistyped something, as in
+<literal>\cite{texbok}</literal> then you need to correct the spelling.  On the
+other hand, if you have just added or modified the bibliographic
+information and so changed the <filename>.aux</filename> file (see <link linkend="_005cbibitem">\bibitem</link>) then
+the fix may be to just run &latex; again.
+</para>
+<para>In addition to what appears in the output, <literal>\cite</literal> writes
+information to the auxiliary file <filename><replaceable>filename</replaceable>.aux</filename>.  For
+instance, <literal>\cite{latexdps}</literal> writes ‘<literal>\citation{latexdps}</literal>’
+to that file.  This information is used by Bib&tex; to include in your
+reference list only those works that you have actually cited; see
+<link linkend="_005cnocite">\nocite</link> also.
+</para>
 
 </sect2>
 <sect2 label="8.24.3" id="_005cnocite">
@@ -5268,9 +6554,14 @@
 </para>
 <screen><literal>\nocite{<replaceable>keys</replaceable>}</literal>
 </screen>
-<para>The <literal>\nocite</literal> command produces no text, but writes <replaceable>keys</replaceable>,
-which is a list of one or more citation keys, to the <filename>.aux</filename> file.
+<para>Produces no output but writes <replaceable>keys</replaceable> to the auxiliary file
+<filename><replaceable>doc-filename</replaceable>.aux</filename>.
 </para>
+<para>The mandatory argument <replaceable>keys</replaceable> is a comma-separated list of one or
+more citation keys (see <link linkend="_005cbibitem">\bibitem</link>).  This information is used by
+Bib&tex; to include these works in your reference list even though you
+have not cited them (see <link linkend="_005ccite">\cite</link>).
+</para>
 
 </sect2>
 <sect2 label="8.24.4" id="Using-BibTeX">
@@ -5282,42 +6573,63 @@
 <indexterm role="fn"><primary>\bibliographystyle</primary></indexterm>
 <indexterm role="fn"><primary>\bibliography</primary></indexterm>
 
-<para>If you use the Bib&tex; program by Oren Patashnik (highly
-recommended if you need a bibliography of more than a couple of
-titles) to maintain your bibliography, you don’t use the
-<literal>thebibliography</literal> environment (see <link linkend="thebibliography">thebibliography</link>). Instead,
-you include the lines
+<para>As described in <literal>thebibliography</literal> (see <link linkend="thebibliography">thebibliography</link>), a
+sophisticated approach to managing bibliographies is provided by the
+Bib&tex; program.  This is only an introduction; see the full
+documentation on CTAN.
 </para>
+<para>With Bib&tex;, you don’t use <literal>thebibliography</literal>
+(see <link linkend="thebibliography">thebibliography</link>). Instead, include these lines.
+</para>
 <screen>\bibliographystyle{<replaceable>bibstyle</replaceable>}
-\bibliography{<replaceable>bibfile1</replaceable>,<replaceable>bibfile2</replaceable>}
+\bibliography{<replaceable>bibfile1</replaceable>, <replaceable>bibfile2</replaceable>, ...}
 </screen>
-<para>The <literal>\bibliographystyle</literal> command does not produce any output of
-its own.  Rather, it defines the style in which the bibliography will
-be produced: <replaceable>bibstyle</replaceable> refers to a file
-<replaceable>bibstyle</replaceable><filename>.bst</filename>, which defines how your citations will look.
-The standard <replaceable>bibstyle</replaceable> names distributed with Bib&tex; are:
+<para>The <replaceable>bibstyle</replaceable> refers to a file <filename><replaceable>bibstyle</replaceable>.bst</filename>, which
+defines how your citations will look.  The standard <replaceable>bibstyle</replaceable>’s
+distributed with Bib&tex; are:
 </para>
 <variablelist><varlistentry><term><literal>alpha</literal>
-</term><listitem><para>Sorted alphabetically. Labels are formed from name of author and year of
-publication.
+</term><listitem><para>Labels are formed from name of author and year of publication.
+The bibliographic items are sorted alphabetically.
 </para></listitem></varlistentry><varlistentry><term><literal>plain</literal>
-</term><listitem><para>Sorted alphabetically. Labels are numeric.
+</term><listitem><para>Labels are integers.
+Sort the  bibliographic items alphabetically.
 </para></listitem></varlistentry><varlistentry><term><literal>unsrt</literal>
 </term><listitem><para>Like <literal>plain</literal>, but entries are in order of citation.
 </para></listitem></varlistentry><varlistentry><term><literal>abbrv</literal>
 </term><listitem><para>Like <literal>plain</literal>, but more compact labels.
 </para></listitem></varlistentry></variablelist>
-<para>In addition, numerous other Bib&tex; style files exist tailored to
-the demands of various publications.  See
+<para>Many, many other Bib&tex; style files exist,
+tailored to the demands of various publications.  See CTAN’s listing
 <ulink url="http://mirror.ctan.org/biblio/bibtex/contrib">http://mirror.ctan.org/biblio/bibtex/contrib</ulink>.
 </para>
 <para>The <literal>\bibliography</literal> command is what actually produces the
-bibliography.  The argument to <literal>\bibliography</literal> refers to files
-named <filename><replaceable>bibfile1</replaceable>.bib</filename>, <filename><replaceable>bibfile2</replaceable>.bib</filename>, …,
-which should contain your database in
-Bib&tex; format.  Only the entries referred to via <literal>\cite</literal> and
-<literal>\nocite</literal> will be listed in the bibliography.
+bibliography.  Its argument is a comma-separated list, referring to
+files named <filename><replaceable>bibfile1</replaceable>.bib</filename>, <filename><replaceable>bibfile2</replaceable>.bib</filename>,
+… These contain your database in Bib&tex; format.  This shows a
+typical couple of entries in that format.
 </para>
+<screen>@book{texbook,
+  title     = {The {{\TeX}}book},
+  author    = {D.E. Knuth},
+  isbn      = {0201134489},
+  series    = {Computers \& typesetting},
+  year      = {1983},
+  publisher = {Addison-Wesley}
+}
+ at book{sexbook,
+    author    = {W.H. Masters and V.E. Johnson},
+    title     = {Human Sexual Response},
+    year      = {1966},
+    publisher = {Bantam Books}
+}
+</screen>
+<para>Only the bibliographic entries referred to via <literal>\cite</literal> and
+<literal>\nocite</literal> will be listed in the document’s bibliography.  Thus you
+can keep all your sources together in one file, or a small number of
+files, and rely on Bib&tex; to include in this document only those that
+you used.
+</para>
 
 </sect2>
 </sect1>
@@ -5332,15 +6644,37 @@
 <para>Synopsis:
 </para>
 <screen>\begin{theorem}
-<replaceable>theorem-text</replaceable>
+  <replaceable>theorem body</replaceable>
 \end{theorem}
 </screen>
-<para>The <literal>theorem</literal> environment produces “Theorem <replaceable>n</replaceable>” in
-boldface followed by <replaceable>theorem-text</replaceable>, where the numbering
-possibilities for <replaceable>n</replaceable> are described under <literal>\newtheorem</literal>
-(see <link linkend="_005cnewtheorem">\newtheorem</link>).
+<para>Produces ‘<literal>Theorem <replaceable>n</replaceable></literal>’ in boldface followed by <replaceable>theorem
+body</replaceable> in italics.  The numbering possibilities for <replaceable>n</replaceable> are described under
+<literal>\newtheorem</literal> (see <link linkend="_005cnewtheorem">\newtheorem</link>).
 </para>
+<screen>\newtheorem{lem}{Lemma}      % in preamble
+\newtheorem{thm}{Theorem}    
+  ...
+\begin{lem}                  % in  document body
+  text of lemma
+\end{lem}
 
+The next result follows immediately.
+\begin{thm}[Gauss]   %  put `Gauss' in parens after theorem head
+  text of theorem
+\end{thm}
+</screen>
+<indexterm role="cp"><primary>package, <literal>amsmath</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>amsmath</literal> package</primary></indexterm>
+
+<indexterm role="cp"><primary>package, <literal>amsthm</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>amsthm</literal> package</primary></indexterm>
+
+<para>Most new documents use the packages <literal>amsthm</literal> and <literal>amsmath</literal>
+from the American Mathematical Society.  Among other things these
+packages include a large number of options for theorem environments,
+such as styling options.
+</para>
+
 </sect1>
 <sect1 label="8.26" id="titlepage">
 <title><literal>titlepage</literal></title>
@@ -5357,15 +6691,12 @@
   ... text and spacing ...
 \end{titlepage}
 </screen>
-<para>Create a title page, a page with no printed page number or heading.  The
-following page will be numbered page one.
+<para>Create a title page, a page with no printed page number or heading and
+with succeeding pages numbered starting with page one.
 </para>
-<para>To instead produce a standard title page without a <literal>titlepage</literal>
-environment you can use <literal>\maketitle</literal> (see <link linkend="_005cmaketitle">\maketitle</link>).
+<para>In this example all formatting, including vertical spacing, is left to
+the author.
 </para>
-<para>Notice in this example that all formatting, including vertical spacing,
-is left to the author.
-</para>
 <screen>\begin{titlepage}
 \vspace*{\stretch{1}}
 \begin{center}
@@ -5387,6 +6718,9 @@
 \vspace{\stretch{2}}
 \end{titlepage}
 </screen>
+<para>To instead produce a standard title page without a <literal>titlepage</literal>
+environment, use <literal>\maketitle</literal> (see <link linkend="_005cmaketitle">\maketitle</link>).
+</para>
 
 </sect1>
 <sect1 label="8.27" id="verbatim">
@@ -5407,16 +6741,53 @@
 <replaceable>literal-text</replaceable>
 \end{verbatim}
 </screen>
-<para>The <literal>verbatim</literal> environment is a paragraph-making environment in
-which &latex; produces exactly what you type in; for instance the
-<literal>\</literal> character produces a printed ‘<literal>\</literal>’.  It turns &latex;
-into a typewriter with carriage returns and blanks having the same
-effect that they would on a typewriter.
-</para>
-<para>The <literal>verbatim</literal> environment uses a monospaced typewriter-like font
+<para>A paragraph-making environment in which &latex; produces as output
+exactly what you type as input.  For instance inside <replaceable>literal-text</replaceable>
+the backslash <literal>\</literal> character does not start commands, it
+produces a printed ‘<literal>\</literal>’, and carriage returns and blanks are taken
+literally.  The output appears in a monospaced typewriter-like font
 (<literal>\tt</literal>).
 </para>
+<screen>\begin{verbatim}
+Symbol swearing: %&$#?!.
+\end{verbatim}
+</screen>
+<para>The only restriction on <literal>literal-text</literal> is that it cannot include
+the string <literal>\end{verbatim}</literal>.
+</para>
+<indexterm role="cp"><primary>package, <literal>cprotect</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>cprotect</literal> package</primary></indexterm>
 
+<para>You cannot use the verbatim environment in the argument to macros, for
+instance in the argument to a <literal>\section</literal>.  This is not the same as
+commands being fragile (see <link linkend="_005cprotect">\protect</link>), instead it just cannot appear
+there. (But the <literal>cprotect</literal> package can help with this.)
+</para>
+<indexterm role="cp"><primary>package, <literal>listings</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>listings</literal> package</primary></indexterm>
+
+<indexterm role="cp"><primary>package, <literal>minted</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>minted</literal> package</primary></indexterm>
+
+<para>One common use of verbatim input is to typeset computer code.  There are
+packages that are an improvement the <literal>verbatim</literal> environment.  For
+instance, one improvement is to allow the verbatim inclusion of external
+files, or parts of those files.  Such packages include <literal>listings</literal>,
+and <literal>minted</literal>.
+</para>
+<indexterm role="cp"><primary>package, <literal>fancyvrb</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>fancyvrb</literal> package</primary></indexterm>
+
+<indexterm role="cp"><primary>package, <literal>verbatimbox</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>verbatimbox</literal> package</primary></indexterm>
+
+<para>A package that provides many more options for verbatim environments is
+<literal>fancyvrb</literal>.  Another is <literal>verbatimbox</literal>.
+</para>
+<para>For a list of all the relevant packages, see CTAN.
+</para>
+
+
 <sect2 label="8.27.1" id="_005cverb">
 <title><literal>\verb</literal></title>
 
@@ -5425,20 +6796,63 @@
 
 <para>Synopsis:
 </para>
-<screen>\verb<replaceable>char</replaceable><replaceable>literal-text</replaceable><replaceable>char</replaceable>
-\verb*<replaceable>char</replaceable><replaceable>literal-text</replaceable><replaceable>char</replaceable>
+<screen>\verb <replaceable>char</replaceable> <replaceable>literal-text</replaceable> <replaceable>char</replaceable>
+\verb* <replaceable>char</replaceable> <replaceable>literal-text</replaceable> <replaceable>char</replaceable>
 </screen>
-<para>The <literal>\verb</literal> command typesets <replaceable>literal-text</replaceable> as it is input,
-including special characters and spaces, using the typewriter
-(<literal>\tt</literal>) font.  No spaces are allowed between <literal>\verb</literal> or
-<literal>\verb*</literal> and the delimiter <replaceable>char</replaceable>, which begins and ends the
-verbatim text.  The delimiter must not appear in <replaceable>literal-text</replaceable>.
+<para>Typeset <replaceable>literal-text</replaceable> as it is input, including special characters
+and spaces, using the typewriter (<literal>\tt</literal>) font.
 </para>
+<para>This example shows two different invocations of <literal>\verb</literal>.
+</para>
+<screen>This is \verb!literally! the biggest pumpkin ever.
+And this is the best squash, \verb+literally!+
+</screen>
+<para>The first <literal>\verb</literal> has its <replaceable>literal-text</replaceable> surrounded with
+exclamation point, <literal>!</literal>.  The second instead uses plus, <literal>+</literal>,
+because the exclamation point is part of <literal>literal-text</literal>.
+</para>
+<para>The single-character delimiter <replaceable>char</replaceable> surrounds
+<replaceable>literal-text</replaceable> — it must be the same character before and
+after.  No spaces come between <literal>\verb</literal> or <literal>\verb*</literal> and
+<replaceable>char</replaceable>, or between <replaceable>char</replaceable> and <replaceable>literal-text</replaceable>, or between
+<replaceable>literal-text</replaceable> and the second occurrence of <replaceable>char</replaceable> (the synopsis
+shows a space only to distinguish one component from the other).  The
+delimiter must not appear in <replaceable>literal-text</replaceable>. The <replaceable>literal-text</replaceable>
+cannot include a line break.
+</para>
 <indexterm role="cp"><primary>visible space</primary></indexterm>
-<para>The <literal>*</literal>-form differs only in that spaces are printed with a
-“visible space” character.
+<para>The <literal>*</literal>-form differs only in that spaces are printed with a visible
+space character.
 </para>
+<para>The output from this will include a character showing the spaces.
+</para>
+<screen>The commands's first argument is \verb*!filename with extension! and ...
+</screen>
+<indexterm role="cp"><primary>package, <literal>url</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>url</literal> package</primary></indexterm>
 
+<para>For typesetting Internet addresses, urls, the package <literal>url</literal>
+provides an option that is better than the <literal>\verb</literal> command, since
+it allows line breaks.
+</para>
+<indexterm role="cp"><primary>package, <literal>listings</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>listings</literal> package</primary></indexterm>
+
+<indexterm role="cp"><primary>package, <literal>minted</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>minted</literal> package</primary></indexterm>
+
+<para>For computer code there are many packages with advantages over
+<literal>\verb</literal>.  One is <filename>listings</filename>, another is <filename>minted</filename>.
+</para>
+<indexterm role="cp"><primary>package, <literal>cprotect</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>cprotect</literal> package</primary></indexterm>
+
+<para>You cannot use <literal>\verb</literal> in the argument to a macro, for instance in
+the argument to a <literal>\section</literal>.  It is not a question of <literal>\verb</literal>
+being fragile (see <link linkend="_005cprotect">\protect</link>), instead it just cannot appear there.
+(But the <literal>cprotect</literal> package can help with this.)
+</para>
+
 </sect2>
 </sect1>
 <sect1 label="8.28" id="verse">
@@ -5452,20 +6866,37 @@
 <para>Synopsis:
 </para>
 <screen>\begin{verse}
-<replaceable>line1</replaceable> \\
-<replaceable>line2</replaceable> \\
-...
+  <replaceable>line1</replaceable> \\
+  <replaceable>line2</replaceable> \\
+  ...
 \end{verse}
 </screen>
-<para>The <literal>verse</literal> environment is designed for poetry, though you may find
-other uses for it.
+<para>An environment for poetry.
 </para>
+<para>Here are two lines from Shakespeare’s Romeo and Juliet.
+</para>
+<screen>Then plainly know my heart's dear love is set \\
+On the fair daughter of rich Capulet.
+</screen>
 <indexterm role="fn"><primary>\\ for <literal>verse</literal></primary></indexterm>
-<para>The margins are indented on the left and the right, paragraphs are not
-indented, and the text is not justified.  Separate the lines of each
-stanza with <literal>\\</literal>, and use one or more blank lines to separate the
-stanzas.
+<para>Separate the lines of each stanza with <literal>\\</literal>, and use one or more
+blank lines to separate the stanzas.
 </para>
+<screen>\begin{verse}
+\makebox[\linewidth][c]{\textit{Shut Not Your Doors} ---Walt Whitman}
+  \\[1\baselineskip]
+Shut not your doors to me proud libraries,                  \\
+For that which was lacking on all your well-fill'd shelves, \\
+\qquad yet needed most, I bring,                             \\
+Forth from the war emerging, a book I have made,            \\
+The words of my book nothing, the drift of it every thing,  \\
+A book separate, not link'd with the rest nor felt by the intellect, \\
+But you ye untold latencies will thrill to every page.
+\end{verse}
+</screen>
+<para>The output has margins indented on the left and the right, paragraphs
+are not indented, and the text is not right-justified.
+</para>
 
 </sect1>
 </chapter>
@@ -5483,6 +6914,12 @@
 <para>&latex; usually does the line (and page) breaking in the text body for
 you but in some environments you manually force line breaks.
 </para>
+<para>A common workflow is to get a final version of the document content
+before taking a final pass through and considering line breaks (and page
+breaks).  This differs from word processing, where you are formatting
+text as you input it.  Putting these off until the end prevents a lot of
+fiddling with breaks that will change anyway.
+</para>
 
 
 <sect1 label="9.1" id="_005c_005c">
@@ -5492,35 +6929,71 @@
 <indexterm role="cp"><primary>new line, starting</primary></indexterm>
 <indexterm role="cp"><primary>line break, forcing</primary></indexterm>
 
-<para>Synopsis:
+<para>Synopsis, one of:
 </para>
-<screen>\\[<replaceable>morespace</replaceable>]
+<screen>\\
+\\[<replaceable>morespace</replaceable>]
 </screen>
-<para>or 
+<para>or one of: 
 </para>
-<screen>\\*[<replaceable>morespace</replaceable>]
+<screen>\\*
+\\*[<replaceable>morespace</replaceable>]
 </screen>
-<para>Start a new line.  The optional argument <replaceable>morespace</replaceable> specifies extra
-vertical space to be insert before the next line.  This can be a
-negative length.  The text before the break is set at its normal length,
-that is, it is not stretched to fill out the line width.
+<para>End the current line.  The optional argument <replaceable>morespace</replaceable> specifies
+extra vertical space to be inserted before the next line.  This is a
+rubber length (see <link linkend="Lengths">Lengths</link>) and can be negative.  The text before
+the line break is set at its normal length, that is, it is not stretched
+to fill out the line width.  This command is fragile (see <link linkend="_005cprotect">\protect</link>).
 </para>
-<para>Explicit line breaks in the text body are unusual in &latex;.  In
-particular, to start a new paragraph instead leave a blank line.  This
-command is mostly used outside of the main flow of text such as in
-a <literal>tabular</literal> or <literal>array</literal> environment.
+<para>The starred form, <literal>\\*</literal>, tells &latex; not to start a new page
+between the two lines, by issuing a <literal>\nobreak</literal>.
 </para>
-<para>Under ordinary circumstances (e.g., outside of a <literal>p{...}</literal> column
-in a <literal>tabular</literal> environment) the <literal>\newline</literal> command is a synonym for
-<literal>\\</literal> (see <link linkend="_005cnewline">\newline</link>).
-</para>
-<para>In addition to starting a new line, the starred form <literal>\\*</literal> tells
-&latex; not to start a new page between the two lines, by issuing a
-<literal>\nobreak</literal>.
-</para>
 <screen>\title{My story: \\[0.25in]
        a tale of woe}
 </screen>
+<para>Explicit line breaks in the main text body are unusual in &latex;.  In
+particular, don’t start new paragraphs with <literal>\\</literal>.  Instead leave a
+blank line between the two paragraphs.  And don’t put in a sequence of
+<literal>\\</literal>’s to make vertical space. Instead use
+<literal>\vspace{<replaceable>length</replaceable>}</literal>, or
+<literal>\leavevmode\vspace{<replaceable>length</replaceable>}</literal>, or
+<literal>\vspace*{<replaceable>length</replaceable>}</literal> if you want the space to not be thrown
+out at the top of a new page (see <link linkend="_005cvspace">\vspace</link>).
+</para>
+<para>The <literal>\\</literal> command is mostly used outside of the main flow of text
+such as in a <literal>tabular</literal> or <literal>array</literal> environment or in an
+equation environment.
+</para>
+<para>The <literal>\\</literal> command is a synonym for <literal>\newline</literal>
+(see <link linkend="_005cnewline">\newline</link>) under ordinary circumstances (an example of an
+exception is the <literal>p{...}</literal> column in a <literal>tabular</literal>
+environment; see <link linkend="tabular">tabular</link>).
+</para>
+<!-- credit: David Carlisle https://tex.stackexchange.com/a/82666 -->
+<para>The <literal>\\</literal> command is a macro, and its definition changes by context
+so that its definition in normal text, a <literal>center</literal> environment, a
+<literal>flushleft</literal> environment, and a <literal>tabular</literal> are all different.
+In normal text when it forces a linebreak it is essentially a shorthand
+for <literal>\newline</literal>.  It does not end horizontal mode or end the
+paragraph, it just inserts some glue and penalties so that when the
+paragraph does end a linebreak will occur at that point, with the short
+line padded with white space.
+</para>
+<para>You get ‘<literal>LaTeX Error: There's no line here to end</literal>’ if you use
+<literal>\\</literal> to ask for a new line, rather than to end the current line.
+An example is if you have <literal>\begin{document}\\</literal> or, more likely,
+something like this.
+</para>
+<screen>\begin{center}
+  \begin{minipage}{0.5\textwidth}
+  \\
+  In that vertical space put your mark.
+  \end{minipage}
+\end{center}
+</screen>
+<para>Fix it by replacing the double backslash with something like
+<literal>\vspace{\baselineskip}</literal>.
+</para>
 
 </sect1>
 <sect1 label="9.2" id="_005cobeycr-_0026-_005crestorecr">
@@ -5530,14 +7003,44 @@
 <indexterm role="fn"><primary>\restorecr</primary></indexterm>
 <indexterm role="cp"><primary>new line, output as input</primary></indexterm>
 
-<para>The <literal>\obeycr</literal> command makes a return in the input file
-(‘<literal>^^M</literal>’, internally) the same as <literal>\\</literal> (followed by
-<literal>\relax</literal>).  So each new line in the input will also be a new line
-in the output.
+<para>The <literal>\obeycr</literal> command makes a return in the input file (‘<literal>^^M</literal>’,
+internally) the same as <literal>\\</literal>, followed by <literal>\relax</literal>.  So each
+new line in the input will also be a new line in the output.  The
+<literal>\restorecr</literal> command restores normal line-breaking behavior.
 </para>
-<para><literal>\restorecr</literal> restores normal line-breaking behavior.
+<para>This is not the way to show verbatim text or computer code.
+See <link linkend="verbatim">verbatim</link> instead.
 </para>
+<para>With &latex;’s usual defaults, this
+</para>
+<screen>aaa
+bbb
 
+\obeycr
+ccc
+ddd
+   eee
+
+\restorecr
+fff
+ggg
+
+hhh
+iii
+</screen>
+<para>produces output like this.
+</para>
+<screen>  aaa bbb
+  ccc
+ddd
+eee
+
+fff ggg
+  hhh iii
+</screen>
+<para>The indents are paragraph indents.
+</para>
+
 </sect1>
 <sect1 label="9.3" id="_005cnewline">
 <title><literal>\newline</literal></title>
@@ -5545,14 +7048,18 @@
 <indexterm role="fn"><primary>\newline</primary></indexterm>
 <indexterm role="cp"><primary>new line, starting (paragraph mode)</primary></indexterm>
 
-<para>In ordinary text this is equivalent to double-backslash (see <link linkend="_005c_005c">\\</link>); it
-breaks a line, with no stretching of the text before it.
+<para>In ordinary text, this ends a line in a way that does not right-justify
+the line, so the prior text is not stretched. That is, in paragraph mode
+(see <link linkend="Modes">Modes</link>), the <literal>\newline</literal> command is equivalent to
+double-backslash (see <link linkend="_005c_005c">\\</link>).  This command is fragile
+(see <link linkend="_005cprotect">\protect</link>).
 </para>
-<para>Inside a <literal>tabular</literal> or <literal>array</literal> environment, in a column with a
-specifier producing a paragraph box, like typically <literal>p{...}</literal>,
-<literal>\newline</literal> will insert a line break inside of the column, that is,
-it does not break the entire row.  To break the entire row use <literal>\\</literal>
-or its equivalent <literal>\tabularnewline</literal>.
+<para>However, the two commands are different inside a <literal>tabular</literal> or
+<literal>array</literal> environment. In a column with a specifier producing a
+paragraph box such as typically <literal>p{...}</literal>, <literal>\newline</literal> will
+insert a line end inside of the column; that is, it does not break the
+entire tabular row.  To break the entire row use <literal>\\</literal> or its
+equivalent <literal>\tabularnewline</literal>.
 </para>
 <para>This will print ‘<literal>Name:</literal>’ and ‘<literal>Address:</literal>’ as two lines in a
 single cell of the table.
@@ -5571,16 +7078,39 @@
 <indexterm role="fn"><primary>\- (hyphenation)</primary></indexterm>
 <indexterm role="cp"><primary>hyphenation, forcing</primary></indexterm>
 
-<para>The <literal>\-</literal> command tells &latex; that it may hyphenate the word at
-that point.  &latex; is pretty good at hyphenating, and usually finds
-most of the correct hyphenation points, while almost never using an
-incorrect one.  The <literal>\-</literal> command is used for the exceptional
-cases.
+<para>Tell &latex; that it may hyphenate the word at that point.  When you
+insert <literal>\-</literal> commands in a word, the word will only be hyphenated at
+those points and not at any of the hyphenation points that &latex;
+might otherwise have chosen.  This command is robust (see <link linkend="_005cprotect">\protect</link>).
 </para>
-<para>When you insert <literal>\-</literal> commands in a word, the word will only be
-hyphenated at those points and not at any of the hyphenation points
-that &latex; might otherwise have chosen.
+<para>&latex; is good at hyphenating and usually finds most of the correct
+hyphenation points, while almost never using an incorrect one.  The
+<literal>\-</literal> command is for exceptional cases.
 </para>
+<para>For example, &latex; does not ordinarily hyphenate words containing a
+hyphen.  Below, the long and hyphenated word means &latex; has to put
+in unacceptably large spaces to set the narrow column.
+</para>
+<screen>\begin{tabular}{rp{1.75in}}
+  Isaac Asimov &The strain of
+               anti-intellectualism
+               % an\-ti-in\-tel\-lec\-tu\-al\-ism
+               has been a constant thread winding its way through our
+               political and cultural life, nurtured by
+               the false notion that democracy means that
+               `my ignorance is just as good as your knowledge'.
+\end{tabular}
+</screen>
+<para>Commenting out the third line and uncommenting the fourth makes a much
+better fit.
+</para>
+<para>The <literal>\-</literal> command only allows &latex; to break there, it does not
+require that it break there.  You can insist on a split with something
+like <literal>Hef-\linebreak feron</literal>.  Of course, if you later change the
+text then this forced break may look very odd, so this approach requires
+care.
+</para>
+
 </sect1>
 <sect1 label="9.5" id="_005cdiscretionary">
 <title><literal>\discretionary</literal> (generalized hyphenation point)</title>
@@ -5589,39 +7119,82 @@
 
 <para>Synopsis:
 </para>
-<screen>\discretionary{<replaceable>pre-break-text</replaceable>}{<replaceable>post-break-text</replaceable>}{<replaceable>no-break-text</replaceable>}
+<screen>\discretionary{<replaceable>pre-break</replaceable>}{<replaceable>post-break</replaceable>}{<replaceable>no-break</replaceable>}
 </screen>
-<!-- xxx TODO, complete this node, see LaTeX-fr -->
+<para>Handle word changes around hyphens.  This command is not often used in
+&latex; documents.
+</para>
+<para>If a line break occurs at the point where <literal>\discretionary</literal> appears
+then &tex; puts <replaceable>pre-break</replaceable> at the end of the current line and puts
+<replaceable>post-break</replaceable> at the start of the next line.  If there is no line
+break here then &tex; puts <replaceable>no-break</replaceable>
+</para>
+<para>In ‘<literal>difficult</literal>’ the three letters <literal>ffi</literal> form a ligature.  But
+&tex; can nonetheless break between the two f’s with this.
+</para>
+<screen>di\discretionary{f-}{fi}{ffi}cult
+</screen>
+<para>Note that users do not have to do this.  It is typically handled
+automatically by &tex;’s hyphenation algorithm.
+</para>
 
 </sect1>
-<sect1 label="9.6" id="_005cfussy">
-<title><literal>\fussy</literal></title>
+<sect1 label="9.6" id="_005cfussy-_0026-_005csloppy">
+<title><literal>\fussy</literal> & <literal>\sloppy</literal></title>
 
 <indexterm role="fn"><primary>\fussy</primary></indexterm>
+<indexterm role="fn"><primary>\sloppy</primary></indexterm>
+<indexterm role="cp"><primary>line breaks, changing</primary></indexterm>
 
-<para>The declaration <literal>\fussy</literal> (which is the default) makes &tex;
-picky about line breaking.  This usually avoids too much space between
-words, at the cost of an occasional overfull box.
+<para>Declarations to make &tex; more picky or less picky about line
+breaking.  Declaring <literal>\fussy</literal> usually avoids too much space between
+words, at the cost of an occasional overfull box.  Conversely,
+<literal>\sloppy</literal> avoids overfull boxes while suffering loose interword
+spacing.
 </para>
-<para>This command cancels the effect of a previous <literal>\sloppy</literal> command
-(see <link linkend="_005csloppy">\sloppy</link>).
+<para>The default is <literal>\fussy</literal>.  Line breaking in a paragraph is
+controlled by whichever declaration is current at the blank line, or
+<literal>\par</literal>, or displayed equation ending that paragraph.  So to affect
+the line breaks, include that paragraph-ending material in the scope of
+the command.
 </para>
 
-</sect1>
-<sect1 label="9.7" id="_005csloppy">
-<title><literal>\sloppy</literal></title>
 
-<indexterm role="fn"><primary>\sloppy</primary></indexterm>
+<sect2 label="9.6.1" id="sloppypar">
+<title><literal>sloppypar</literal></title>
 
-<para>The declaration <literal>\sloppy</literal> makes &tex; less fussy about line
-breaking. This will avoid overfull boxes, at the cost of loose
-interword spacing.
+<indexterm role="fn"><primary>sloppypar</primary></indexterm>
+<indexterm role="cp"><primary>sloppypar environment</primary></indexterm>
+
+<para>Synopsis:
 </para>
-<para>Lasts until a <literal>\fussy</literal> command is issued (see <link linkend="_005cfussy">\fussy</link>).
+<screen>\begin{sloppypar}
+  ... paragraphs ...
+\end{sloppypar}
+</screen>
+<para>Typeset the paragraphs with <literal>\sloppy</literal> in effect (see <link linkend="_005cfussy-_0026-_005csloppy">\fussy &
+\sloppy</link>).  Use this to locally adjust line breaking, to avoid
+‘<literal>Overfull box</literal>’ or ‘<literal>Underfull box</literal>’ errors.
 </para>
+<para>The example is simple.
+</para>
+<screen>\begin{sloppypar}
+  Her plan for the morning thus settled, she sat quietly down to her
+  book after breakfast, resolving to remain in the same place and the
+  same employment till the clock struck one; and from habitude very
+  little incommoded by the remarks and ejaculations of Mrs.\ Allen,
+  whose vacancy of mind and incapacity for thinking were such, that
+  as she never talked a great deal, so she could never be entirely
+  silent; and, therefore, while she sat at her work, if she lost her
+  needle or broke her thread, if she heard a carriage in the street,
+  or saw a speck upon her gown, she must observe it aloud, whether
+  there were anyone at leisure to answer her or not.
+\end{sloppypar}
+</screen>
 
+</sect2>
 </sect1>
-<sect1 label="9.8" id="_005chyphenation">
+<sect1 label="9.7" id="_005chyphenation">
 <title><literal>\hyphenation</literal></title>
 
 <indexterm role="fn"><primary>\hyphenation</primary></indexterm>
@@ -5629,20 +7202,22 @@
 
 <para>Synopsis:
 </para>
-<screen>\hyphenation{<replaceable>word-one</replaceable> <replaceable>word-two</replaceable>}
+<screen>\hyphenation{<replaceable>word1</replaceable> ...}
 </screen>
-<para>The <literal>\hyphenation</literal> command declares allowed hyphenation points
-with a <literal>-</literal> character in the given words.  The words are separated
-by spaces.  &tex; will only hyphenate if the word matches exactly, no
-inflections are tried.  Multiple <literal>\hyphenation</literal> commands
-accumulate.  Some examples (the default &tex; hyphenation patterns
-misses the hyphenations in these words):
+<para>Declares allowed hyphenation points within the words in the list.  The
+words in that list are separated by spaces.  Show permitted points for
+hyphenation with a dash character, <literal>-</literal>.
 </para>
-<screen>\hyphenation{ap-pen-dix col-umns data-base data-bases}
+<para>Here is an example:
+</para>
+<screen>\hyphenation{hat-er il-lit-e-ra-ti tru-th-i-ness}
 </screen>
+<para>Use lowercase letters.  &tex; will only hyphenate if the word matches
+exactly.  Multiple <literal>\hyphenation</literal> commands accumulate.
+</para>
 
 </sect1>
-<sect1 label="9.9" id="_005clinebreak-_0026-_005cnolinebreak">
+<sect1 label="9.8" id="_005clinebreak-_0026-_005cnolinebreak">
 <title><literal>\linebreak</literal> & <literal>\nolinebreak</literal></title>
 
 <indexterm role="fn"><primary>\linebreak</primary></indexterm>
@@ -5650,21 +7225,37 @@
 <indexterm role="cp"><primary>line breaks, forcing</primary></indexterm>
 <indexterm role="cp"><primary>line breaks, preventing</primary></indexterm>
 
-<para>Synopses:
+<para>Synopses, one of:
 </para>
-<screen>\linebreak[<replaceable>priority</replaceable>]
-\nolinebreak[<replaceable>priority</replaceable>]
+<screen>\linebreak
+\linebreak[<replaceable>zero-to-four</replaceable>]
 </screen>
-<para>By default, the <literal>\linebreak</literal> (<literal>\nolinebreak</literal>) command forces
-(prevents) a line break at the current position.  For
-<literal>\linebreak</literal>, the spaces in the line are stretched out so that it
-extends to the right margin as usual.
+<para>or one of these.
 </para>
-<para>With the optional argument <replaceable>priority</replaceable>, you can convert the command
-from a demand to a request.  The <replaceable>priority</replaceable> must be a number from
-0 to 4.  The higher the number, the more insistent the request.
+<screen>\nolinebreak
+\nolinebreak[<replaceable>zero-to-four</replaceable>]
+</screen>
+<para>Encourage or discourage a line break.  The optional <replaceable>zero-to-four</replaceable>
+is an integer that allows you to soften the instruction.  The default is
+4, so that without the optional argument these commands entirely force
+or prevent the break.  But for instance, <literal>\nolinebreak[1]</literal> is a
+suggestion that another place may be better.  The higher the number, the
+more insistent the request.  Both commands are fragile
+(see <link linkend="_005cprotect">\protect</link>).
 </para>
+<para>Here we tell &latex; that a good place to put a linebreak is after the
+standard legal text.
+</para>
+<screen>\boilerplatelegal{} \linebreak[2]
+We especially encourage applications from members of traditionally
+underrepresented groups.
+</screen>
+<para>When you issue <literal>\linebreak</literal>, the spaces in the line are stretched
+out so that it extends to the right margin.  See <link linkend="_005c_005c">\\</link>
+and <link linkend="_005cnewline">\newline</link> to have the spaces not stretched out.
+</para>
 
+
 </sect1>
 </chapter>
 <chapter label="10" id="Page-breaking">
@@ -5673,72 +7264,160 @@
 <indexterm role="cp"><primary>page breaking</primary></indexterm>
 <indexterm role="cp"><primary>breaking pages</primary></indexterm>
 
-<para>&latex; starts new pages asynchronously, when enough material has
-accumulated to fill up a page.  Usually this happens automatically,
-but sometimes you may want to influence the breaks.
+<para>Ordinarily &latex; automatically takes care of breaking output into
+pages with its usual aplomb.  But if you are writing commands, or
+tweaking the final version of a document, then you may need to
+understand how to influence its actions.
 </para>
+<!-- credit: H Vogt https://tex.stackexchange.com/a/115563 -->
+<para>&latex;’s algorithm for splitting a document into pages is more complex
+than just waiting until there is enough material to fill a page and
+outputting the result.  Instead, &latex; typesets more material than
+would fit on the page and then chooses a break that is optimal in some
+way (it has the smallest badness). An example of the advantage of this
+approach is that if the page has some vertical space that can be
+stretched or shrunk, such as with rubber lengths between paragraphs,
+then &latex; can use that to avoid widow lines (where a new page starts
+with the last line of a paragraph; &latex; can squeeze the extra line
+onto the first page) and orphans (where the first line of paragraph is
+at the end of a page; &latex; can stretch the material of the first
+page so the extra line falls on the second page). Another example is
+where &latex; uses available vertical shrinkage to fit on a page not
+just the header for a new section but also the first two lines of that
+section.
+</para>
+<para>But &latex; does not optimize over the entire document’s set of page
+breaks. So it can happen that the first page break is great but the
+second one is lousy; to break the current page &latex; doesn’t look as
+far ahead as the next page break.  So occasionally you may want to
+influence page breaks while preparing a final version of a document.
+</para>
+<para>See <link linkend="Layout">Layout</link> for more material that is relevant to page breaking.
+</para>
 
 
-<sect1 label="10.1" id="_005ccleardoublepage">
-<title><literal>\cleardoublepage</literal></title>
+<sect1 label="10.1" id="_005cclearpage-_0026-_005ccleardoublepage">
+<title><literal>\clearpage</literal> & <literal>\cleardoublepage</literal></title>
 
+<indexterm role="fn"><primary>\clearpage</primary></indexterm>
+<indexterm role="cp"><primary>flushing floats and starting a page</primary></indexterm>
+<indexterm role="cp"><primary>starting a new page and clearing floats</primary></indexterm>
 <indexterm role="fn"><primary>\cleardoublepage</primary></indexterm>
 <indexterm role="cp"><primary>starting on a right-hand page</primary></indexterm>
 
-<para>The <literal>\cleardoublepage</literal> command ends the current page and causes all
-the pending floating figures and tables that have so far appeared in the
-input to be printed.  In a two-sided printing style, it also makes the
-next page a right-hand (odd-numbered) page, producing a blank page if
-necessary.
+<para>Synopsis:
 </para>
+<screen>\clearpage
+</screen>
+<para>or
+</para>
+<screen>\cleardoublepage
+</screen>
+<para>End the current page and output all of the pending floating figures and
+tables (see <link linkend="Floats">Floats</link>).  If there are too many floats to fit on the
+page then &latex; will put in extra pages containing only floats.  In
+two-sided printing, <literal>\cleardoublepage</literal> also makes the next page of
+content a right-hand page, an odd-numbered page, if necessary inserting
+a blank page.  The <literal>\clearpage</literal> command is robust while
+<literal>\cleardoublepage</literal> is fragile (see <link linkend="_005cprotect">\protect</link>).
+</para>
+<para>&latex;’s page breaks are optimized so ordinarily you only use this
+command in a document body to polish the final version, or inside
+commands.
+</para>
+<!-- credit: https://www.tex.ac.uk/FAQ-reallyblank.html -->
+<para>The <literal>\cleardoublepage</literal> command will put in a blank page, but it
+will have the running headers and footers.  To get a really blank
+page, use this command.
+</para>
+<screen>\let\origdoublepage\cleardoublepage
+\newcommand{\clearemptydoublepage}{%
+  \clearpage
+  {\pagestyle{empty}\origdoublepage}%
+}
+</screen>
+<para>If you want &latex;’s standard <literal>\chapter</literal> command to do this then
+add the line <literal>\let\cleardoublepage\clearemptydoublepage</literal>.
+</para>
+<para>The command <literal>\newpage</literal> (see <link linkend="_005cnewpage">\newpage</link>) also ends the current
+page, but without clearing pending floats.  And, if &latex; is in
+two-column mode then <literal>\newpage</literal> ends the current column while
+<literal>\clearpage</literal> and <literal>\cleardoublepage</literal> end the current page.
+</para>
 
-</sect1>
-<sect1 label="10.2" id="_005cclearpage">
-<title><literal>\clearpage</literal></title>
 
-<indexterm role="fn"><primary>\clearpage</primary></indexterm>
-<indexterm role="cp"><primary>flushing floats and starting a page</primary></indexterm>
-<indexterm role="cp"><primary>starting a new page and clearing floats</primary></indexterm>
-
-<para>The <literal>\clearpage</literal> command ends the current page and causes all the
-pending floating figures and tables that have so far appeared in the
-input to be printed.
-</para>
-
 </sect1>
-<sect1 label="10.3" id="_005cnewpage">
+<sect1 label="10.2" id="_005cnewpage">
 <title><literal>\newpage</literal></title>
 
 <indexterm role="fn"><primary>\newpage</primary></indexterm>
 <indexterm role="cp"><primary>new page, starting</primary></indexterm>
 <indexterm role="cp"><primary>starting a new page</primary></indexterm>
 
-<para>The <literal>\newpage</literal> command ends the current page, but does not clear
-floats (see <link linkend="_005cclearpage">\clearpage</link>).
+<para>Synopsis:
 </para>
+<screen>\newpage
+</screen>
+<para>End the current page.  This command is robust (see <link linkend="_005cprotect">\protect</link>).
+</para>
+<para>&latex;’s page breaks are optimized so ordinarily you only use this
+command in a document body to polish the final version, or inside
+commands.
+</para>
+<para>While the commands <literal>\clearpage</literal> and <literal>\cleardoublepage</literal> also
+end the current page, in addition they clear pending floats
+(see <link linkend="_005cclearpage-_0026-_005ccleardoublepage">\clearpage & \cleardoublepage</link>).  And, if &latex; is in
+two-column mode then <literal>\clearpage</literal> and <literal>\cleardoublepage</literal> end
+the current page, possibly leaving an empty column, while
+<literal>\newpage</literal> only ends the current column.
+</para>
+<para>In contrast with <literal>\pagebreak</literal> (see <link linkend="_005cpagebreak-_0026-_005cnopagebreak">\pagebreak & \nopagebreak</link>),
+the <literal>\newpage</literal> command will cause the new page to start right where
+requested.  This
+</para>
+<screen>Four score and seven years ago our fathers brought forth on this
+continent,
+\newpage
+\noindent a new nation, conceived in Liberty, and dedicated to the
+proposition that all men are created equal.
+</screen>
+<para>makes a new page start after ‘<literal>continent,</literal>’ and the cut-off line is
+not right justified.  In addition, <literal>\newpage</literal> does not vertically
+stretch out the page, as <literal>\pagebreak</literal> does.
+</para>
 
 </sect1>
-<sect1 label="10.4" id="_005cenlargethispage">
+<sect1 label="10.3" id="_005cenlargethispage">
 <title><literal>\enlargethispage</literal></title>
 
 <indexterm role="fn"><primary>\enlargethispage</primary></indexterm>
 <indexterm role="cp"><primary>enlarge current page</primary></indexterm>
 
-<para><literal>\enlargethispage{size}</literal>
+<para>Synopsis, one of:
 </para>
-<para><literal>\enlargethispage*{size}</literal>
+<screen>\enlargethispage{size}
+\enlargethispage*{size}
+</screen>
+<para>Enlarge the <literal>\textheight</literal> for the current page.  The required
+argument <replaceable>size</replaceable> must be a rigid length (see <link linkend="Lengths">Lengths</link>).  It may be
+positive or negative.  This command is fragile (see <link linkend="_005cprotect">\protect</link>).
 </para>
-<para>Enlarge the <literal>\textheight</literal> for the current page by the specified
-amount; e.g., <literal>\enlargethispage{\baselineskip}</literal> will allow one
-additional line.
+<para>A common strategy is to wait until you have the final text of a
+document, and then pass through it tweaking line and page breaks.  This
+command allows you some page size leeway.
 </para>
-<para>The starred form tries to squeeze the material together on the page as
-much as possible. This is normally used together with an explicit
-<literal>\pagebreak</literal>.
+<para>This will allow one extra line on the current page.
 </para>
+<screen>\enlargethispage{\baselineskip}
+</screen>
+<para>The starred form <literal>\enlargesthispage*</literal> tries to squeeze the material
+together on the page as much as possible, for the common use case of
+getting one more line on the page. This is often used together with an
+explicit <literal>\pagebreak</literal>.
+</para>
 
 </sect1>
-<sect1 label="10.5" id="_005cpagebreak-_0026-_005cnopagebreak">
+<sect1 label="10.4" id="_005cpagebreak-_0026-_005cnopagebreak">
 <title><literal>\pagebreak</literal> & <literal>\nopagebreak</literal></title>
 
 <indexterm role="fn"><primary>\pagebreak</primary></indexterm>
@@ -5748,19 +7427,44 @@
 
 <para>Synopses:
 </para>
-<screen>\pagebreak[<replaceable>priority</replaceable>]
-\nopagebreak[<replaceable>priority</replaceable>]
+<screen>\pagebreak
+\pagebreak[<replaceable>zero-to-four</replaceable>]
 </screen>
-<para>By default, the <literal>\pagebreak</literal> (<literal>\nopagebreak</literal>) command forces
-(prevents) a page break at the current position.  With
-<literal>\pagebreak</literal>, the vertical space on the page is stretched out
-where possible so that it extends to the normal bottom margin.
+<para>or
 </para>
-<para>With the optional argument <replaceable>priority</replaceable>, you can convert the
-<literal>\pagebreak</literal> command from a demand to a request.  The number must
-be a number from 0 to 4.  The higher the number, the more
-insistent the request is.
+<screen>\nopagebreak
+\nopagebreak[<replaceable>zero-to-four</replaceable>]
+</screen>
+<para>Encourage or discourage a page break.  The optional <replaceable>zero-to-four</replaceable>
+is an integer that allows you to soften the request. The default is 4,
+so that without the optional argument these commands entirely force or
+prevent the break.  But for instance <literal>\nopagebreak[1]</literal> suggests to
+&latex; that another spot might be preferable.  The higher the number,
+the more insistent the request.  Both commands are fragile
+(see <link linkend="_005cprotect">\protect</link>).
 </para>
+<para>&latex;’s page endings are optimized so ordinarily you only use this
+command in a document body to polish the final version, or inside
+commands.
+</para>
+<para>If you use these inside a paragraph, they apply to the point following
+the line in which they appear.  So this
+</para>
+<screen>Four score and seven years ago our fathers brought forth on this
+continent,
+\pagebreak
+a new nation, conceived in Liberty, and dedicated to the proposition
+that all men are created equal.
+</screen>
+<para>does not give a page break at ‘<literal>continent,</literal>’ but instead at
+‘<literal>nation,</literal>’ since that is where &latex; breaks that line.  In
+addition, with <literal>\pagebreak</literal> the vertical space on the page is
+stretched out where possible so that it extends to the normal bottom
+margin.  This can look strange, and if <literal>\flushbottom</literal> is in effect
+this can cause you to get ‘<literal>Underfull \vbox (badness 10000) has
+occurred while \output is active</literal>’.  See <link linkend="_005cnewpage">\newpage</link> for a command that
+does not have these effects.
+</para>
 
 </sect1>
 </chapter>
@@ -5769,21 +7473,22 @@
 
 <indexterm role="cp"><primary>footnotes, creating</primary></indexterm>
 
-<para>Place a numbered footnote at the bottom of the current page, as here.
+<para>Place a footnote at the bottom of the current page, as here.
 </para>
 <screen>Noël Coward quipped that having to read a footnote is like having
 to go downstairs to answer the door, while in the midst of making
-love.\footnote{I wouldn't know, I don't read footnotes.}
+love.\footnote{%
+  I wouldn't know, I don't read footnotes.}
 </screen>
-<para>You can place multiple footnotes on a page. If the text becomes too long
-it will flow to the next page.
+<para>You can put multiple footnotes on a page. If the footnote text becomes
+too long then it will flow to the next page.
 </para>
 <para>You can also produce footnotes by combining the <literal>\footnotemark</literal> and
 the <literal>\footnotetext</literal> commands, which is useful in special
 circumstances.
 </para>
 <para>To make bibliographic references come out as footnotes you need to
-include a bibliographic style with that behavior.
+include a bibliographic style with that behavior (see <link linkend="Using-BibTeX">Using BibTeX</link>).
 </para>
 
 
@@ -5792,47 +7497,77 @@
 
 <indexterm role="fn"><primary>\footnote</primary></indexterm>
 
-<para>Synopsis:
+<para>Synopsis, one of:
 </para>
-<screen>\footnote[<replaceable>number</replaceable>]{<replaceable>text</replaceable>}
+<screen>\footnote{<replaceable>text</replaceable>}
+\footnote[<replaceable>number</replaceable>]{<replaceable>text</replaceable>}
 </screen>
-<para>Place a numbered footnote <replaceable>text</replaceable> at the bottom of the current page.
+<para>Place a footnote <replaceable>text</replaceable> at the bottom of the current page.
 </para>
 <screen>There are over a thousand footnotes in Gibbon's 
-\textit{Decline and Fall of the Roman Empire}.\footnote{After
-reading an early version with endnotes David Hume complained, 
-``One is also plagued with his Notes, according to the present Method 
-of printing the Book'' and suggested that they ``only to be printed 
-at the Margin or the Bottom of the Page.''}
+\textit{Decline and Fall of the Roman Empire}.\footnote{%
+  After reading an early version with endnotes David Hume complained, 
+  ``One is also plagued with his Notes, according to the present Method 
+  of printing the Book'' and suggested that they ``only to be printed 
+  at the Margin or the Bottom of the Page.''}
 </screen>
-<para>The optional argument <replaceable>number</replaceable> allows you to specify the footnote
-number.  If you use this option then the footnote number counter is not
-incremented, and if you do not use it then the counter is incremented.
+<para>The optional argument <replaceable>number</replaceable> allows you to specify the number of
+the footnote.  If you use this then &latex; does not increment the
+<literal>footnote</literal> counter.
 </para>
 <indexterm role="cp"><primary>footnotes, symbols instead of numbers</primary></indexterm>
 <indexterm role="fn"><primary>\fnsymbol, and footnotes</primary></indexterm>
 <indexterm role="fn"><primary>\@fnsymbol</primary></indexterm>
-<para>Change how &latex; shows the footnote counter with something like
+<para>By default, &latex; uses arabic numbers as footnote markers.  Change
+this with something like
 <literal>\renewcommand{\thefootnote}{\fnsymbol{footnote}}</literal>, which
 uses a sequence of symbols (see <link linkend="_005calph-_005cAlph-_005carabic-_005croman-_005cRoman-_005cfnsymbol">\alph \Alph \arabic \roman \Roman
 \fnsymbol</link>).  To make this change global put that in the preamble.  If
 you make the change local then you may want to reset the counter with
-<literal>\setcounter{footnote}{0}</literal>.  By default &latex; uses arabic
-numbers.
+<literal>\setcounter{footnote}{0}</literal>.
 </para>
+<para>&latex; determines the spacing of footnotes with two parameters.
+</para>
+<indexterm role="cp"><primary>footnote parameters</primary></indexterm>
+<indexterm role="cp"><primary>parameters, for footnotes</primary></indexterm>
+
+<variablelist><varlistentry><term><indexterm role="fn"><primary>\footnoterule</primary></indexterm><literal>\footnoterule</literal>
+</term><listitem><anchor id="footnote-footnoterule"/><para>Produces the rule separating the main text on a page from the page’s
+footnotes.  Default dimensions in the standard document classes (except
+<literal>slides</literal>, where it does not appear) is: vertical thickness of
+<literal>0.4pt</literal>, and horizontal size of <literal>0.4\columnwidth</literal> long.
+Change the rule with something like this.
+</para>
+<!-- Credit egreg: https://tex.stackexchange.com/a/21917 -->
+<screen>\renewcommand{\footnoterule}{% Kerns avoid vertical space
+  \kern -3pt                         % This -3 is negative
+  \hrule width \textwidth height 1pt % of the sum of this 1
+  \kern 2pt}                         % and this 2
+</screen>
+</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\footnotesep</primary></indexterm><literal>\footnotesep</literal>
+</term><listitem><anchor id="footnote-footnotesep"/><para>The height of the strut placed at the beginning of the footnote
+(see <link linkend="_005cstrut">\strut</link>).  By default, this is set to the normal strut for
+<literal>\footnotesize</literal> fonts (see <link linkend="Font-sizes">Font sizes</link>), therefore there is no
+extra space between footnotes.  This is ‘<literal>6.65pt</literal>’ for ‘<literal>10pt</literal>’,
+‘<literal>7.7pt</literal>’ for ‘<literal>11pt</literal>’, and ‘<literal>8.4pt</literal>’ for ‘<literal>12pt</literal>’.  Change
+it as with <literal>\setlength{\footnotesep}{11pt}</literal>.
+</para>
+</listitem></varlistentry></variablelist>
+<para>The <literal>\footnote</literal> command is fragile (see <link linkend="_005cprotect">\protect</link>).
+</para>
 <para>&latex;’s default puts many restrictions on where you can use a
 <literal>\footnote</literal>; for instance, you cannot use it in an argument to a
 sectioning command such as <literal>\chapter</literal> (it can only be used in outer
-paragraph mode).  There are some workarounds; see following sections.
-<!-- xx mention packages that fix this -->
+paragraph mode; see <link linkend="Modes">Modes</link>).  There are some workarounds; see
+following sections.
 </para>
 <indexterm role="cp"><primary>Footnotes, in a minipage</primary></indexterm>
 <indexterm role="cp"><primary>mpfootnote counter</primary></indexterm>
-<para>In a <literal>minipage</literal> environment the <literal>\footnote</literal>
-command uses the <literal>mpfootnote</literal> counter instead of the
-<literal>footnote</literal> counter, so they are numbered independently.  They are
-shown at the bottom of the environment, not at the bottom of the page.
-And by default they are shown alphabetically. See <link linkend="minipage">minipage</link>.
+<para>In a <literal>minipage</literal> environment the <literal>\footnote</literal> command uses the
+<literal>mpfootnote</literal> counter instead of the <literal>footnote</literal> counter, so
+they are numbered independently.  They are shown at the bottom of the
+environment, not at the bottom of the page.  And by default they are
+shown alphabetically. See <link linkend="minipage">minipage</link> and <link linkend="Footnotes-in-a-table">Footnotes in a table</link>.
 </para>
 
 </sect1>
@@ -5846,15 +7581,26 @@
 <screen>\footnotemark
 \footnotemark[<replaceable>number</replaceable>]
 </screen>
-<para>Put the current footnote number in the
-text. (See <link linkend="_005cfootnotetext">\footnotetext</link> for giving the text of the footnote
-separately.)  The version with the optional argument <replaceable>number</replaceable> uses
-that number to determine the mark printed. This command can be used in
-inner paragraph mode.
+<para>Put the current footnote mark in the text. To specify associated text
+for the footnote see <link linkend="_005cfootnotetext">\footnotetext</link>.  The optional argument
+<replaceable>number</replaceable> causes the command to use that number to determine the
+footnote mark. This command can be used in inner paragraph mode
+(see <link linkend="Modes">Modes</link>).
 </para>
-<para>This example gives the same institutional affiliation to both the first
-and third authors (<literal>\thanks</literal> is a version of <literal>footnote</literal>).
+<para>If you use <literal>\footnotemark</literal> without the optional argument then it
+increments the footnote counter but if you use the optional <replaceable>number</replaceable>
+then it does not. The next example produces several consecutive footnote
+markers referring to the same footnote.
 </para>
+<screen>The first theorem\footnote{Due to Gauss.} 
+and the second theorem\footnotemark[\value{footnote}] 
+and the third theorem.\footnotemark[\value{footnote}]
+</screen>
+<para>If there are intervening footnotes then you must remember the value of the
+common mark.  This example gives the same institutional affiliation to
+both the first and third authors (<literal>\thanks</literal> is a version of
+<literal>footnote</literal>), by-hand giving the number of the footnote.
+</para>
 <screen>\title{A Treatise on the Binomial Theorem}
 \author{J Moriarty\thanks{University of Leeds} 
   \and A C Doyle\thanks{Durham University} 
@@ -5862,16 +7608,39 @@
 \begin{document}
 \maketitle
 </screen>
-<para>If you use <literal>\footnotemark</literal> without the optional argument then it
-increments the footnote counter but if you use the optional <replaceable>number</replaceable>
-then it does not. This produces several consecutive footnote markers
-referring to the same footnote.
+<para>This uses a counter to remember the footnote number.  The third sentence
+is followed by the same footnote marker as the first.
 </para>
-<screen>The first theorem\footnote{Due to Gauss.} 
-and the second theorem\footnotemark[\value{footnote}] 
-and the third theorem.\footnotemark[\value{footnote}]
+<screen>\newcounter{footnoteValueSaver}
+All babies are illogical.\footnote{%
+  Lewis Carroll.}\setcounter{footnoteValueSaver}{\value{footnote}}
+Nobody is despised who can manage a crocodile.\footnote{%
+  Captain Hook.}
+Illogical persons are despised.\footnotemark[\value{footnoteValueSaver}]
+Therefore, anyone who can manage a crocodile is not a baby.
 </screen>
+<indexterm role="cp"><primary>package, <literal>cleveref</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>cleveref</literal> package</primary></indexterm>
 
+<indexterm role="cp"><primary>package, <literal>hyperref</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>hyperref</literal> package</primary></indexterm>
+
+<para>This example accomplishes the same by using the package <filename>cleveref</filename>.
+</para>
+<!-- from SE user Jake http://tex.stackexchange.com/a/10116/339 -->
+<screen>\usepackage{cleveref}[2012/02/15]   % in preamble 
+\crefformat{footnote}{#2\footnotemark[#1]#3}
+...
+The theorem is from Evers.\footnote{\label{fn:TE}Tinker, Evers, 1994.}
+The corollary is from Chance.\footnote{Evers, Chance, 1990.}
+But the key lemma is from Tinker.\cref{fn:TE}
+</screen>
+<indexterm role="cp"><primary>package, <literal>hyperref</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>hyperref</literal> package</primary></indexterm>
+
+<para>It will work with the package <filename>hyperref</filename>.
+</para>
+
 </sect1>
 <sect1 label="11.3" id="_005cfootnotetext">
 <title><literal>\footnotetext</literal></title>
@@ -5883,158 +7652,138 @@
 <screen>\footnotetext{<replaceable>text</replaceable>}
 \footnotetext[<replaceable>number</replaceable>]{<replaceable>text</replaceable>}
 </screen>
-<para>Place <replaceable>text</replaceable> at the bottom of the page as a footnote.  This command
-can come anywhere after the <literal>\footnotemark</literal> command.  The optional
-argument <replaceable>number</replaceable> changes the displayed footnote number.  The
-<literal>\footnotetext</literal> command must appear in outer paragraph mode.
+<para>Place <replaceable>text</replaceable> at the bottom of the page as a footnote.  It pairs with
+<literal>\footnotemark</literal> (see <link linkend="_005cfootnotemark">\footnotemark</link>) and can come anywhere after
+that command, but must appear in outer paragraph mode (see <link linkend="Modes">Modes</link>).
+The optional argument <replaceable>number</replaceable> changes the number of the footnote
+mark.
 </para>
+<para>See <link linkend="_005cfootnotemark">\footnotemark</link> and <link linkend="Footnotes-in-a-table">Footnotes in a table</link> for usage
+examples.
+</para>
 
 </sect1>
-<sect1 label="11.4" id="Footnotes-in-a-table">
+<sect1 label="11.4" id="Footnotes-in-section-headings">
+<title>Footnotes in section headings</title>
+
+<indexterm role="cp"><primary>footnote, in section headings</primary></indexterm>
+<indexterm role="cp"><primary>table of contents, avoiding footnotes</primary></indexterm>
+
+<para>Putting a footnote in a section heading, as in:
+</para>
+<screen>\section{Full sets\protect\footnote{This material due to ...}}
+</screen>
+<para>causes the footnote to appear at the bottom of the page where the
+section starts, as usual, but also at the bottom of the table of
+contents, where it is not likely to be desired.  The simplest way
+to have it not appear on the table of contents is to use the optional
+argument to <literal>\section</literal>
+</para>
+<screen>\section[Please]{Please\footnote{%
+  Don't footnote in chapter and section headers!}}
+</screen>
+<para>No <literal>\protect</literal> is needed in front of <literal>\footnote</literal> here because
+what gets moved to the table of contents is the optional argument.
+</para>
+
+</sect1>
+<sect1 label="11.5" id="Footnotes-in-a-table">
 <title>Footnotes in a table</title>
 
-<indexterm role="cp"><primary>Footnotes, in a table</primary></indexterm>
+<indexterm role="cp"><primary>footnote, in a table</primary></indexterm>
 
-<para>Inside a <literal>table</literal> environment the <literal>\footnote</literal> command does not
-work.  For instance, if the code below appears on its own then the
-footnote simply disappears; there is a footnote mark in the table cell
-but nothing is set at the bottom of the page.
+<para>Inside a <literal>tabular</literal> or <literal>array</literal> environment the <literal>\footnote</literal>
+command does not work; there is a footnote mark in the table cell but
+the footnote text does not appear.  The solution is to use a
+<literal>minipage</literal> environment as here (see <link linkend="minipage">minipage</link>).
 </para>
 <screen>\begin{center}
+  \begin{minipage}{\textwidth} \centering
      \begin{tabular}{l|l}
-     \textsc{Ship}  &\textsc{Book} \\ \hline 
-     \textit{HMS Sophie}     &Master and Commander  \\ 
-     \textit{HMS Polychrest} &Post Captain  \\  
-     \textit{HMS Lively}     &Post Captain \\
-     \textit{HMS Surprise}   &A number of books\footnote{Starting with
-                                HMS Surprise.}
+       \textsc{Ship}           &\textsc{Book} \\ \hline 
+       \textit{HMS Sophie}     &Master and Commander  \\ 
+       \textit{HMS Polychrest} &Post Captain  \\  
+       \textit{HMS Lively}     &Post Captain \\
+       \textit{HMS Surprise}   &A number of books\footnote{%
+                                  Starting with HMS Surprise.}
      \end{tabular}
+  \end{minipage}                              
 \end{center}
 </screen>
-<para>The solution is to surround the <literal>tabular</literal> environment with a
-<literal>minipage</literal> environment, as here (see <link linkend="minipage">minipage</link>).
+<para>Inside a <literal>minipage</literal>, footnote marks are lowercase letters.  Change
+that with something like
+<literal>\renewcommand{\thempfootnote}{\arabic{mpfootnote}}</literal>
+(see <link linkend="_005calph-_005cAlph-_005carabic-_005croman-_005cRoman-_005cfnsymbol">\alph \Alph \arabic \roman \Roman \fnsymbol</link>).
 </para>
-<screen>\begin{center}
-  \begin{minipage}{.5\textwidth}
-    ... tabular material ...
-  \end{minipage}
+<para>The footnotes in the prior example appear at the bottom of the
+<literal>minipage</literal>.  To have them appear at the bottom of the main page, as
+part of the regular footnote sequence, use the <literal>\footnotemark</literal> and
+<literal>\footnotetext</literal> pair and make a new counter.
+</para>
+<screen>\newcounter{mpFootnoteValueSaver}
+\begin{center}
+  \begin{minipage}{\textwidth}
+    \setcounter{mpFootnoteValueSaver}{\value{footnote}} \centering
+     \begin{tabular}{l|l}
+       \textsc{Woman}             &\textsc{Relationship} \\ \hline 
+       Mona                       &Attached\footnotemark  \\ 
+       Diana Villiers             &Eventual wife  \\  
+       Christine Hatherleigh Wood &Fiance\footnotemark 
+     \end{tabular}
+  \end{minipage}%  percent sign keeps footnote text close to minipage
+  \stepcounter{mpFootnoteValueSaver}%
+    \footnotetext[\value{mpFootnoteValueSaver}]{%
+      Little is known other than her death.}%
+  \stepcounter{mpFootnoteValueSaver}%
+    \footnotetext[\value{mpFootnoteValueSaver}]{%
+      Relationship is unresolved in XXI.}
 \end{center}
 </screen>
-<para>The same technique will work inside a floating <literal>table</literal> environment
-(see <link linkend="table">table</link>).  To get the footnote at the bottom of the page use the
-<filename>tablefootnote</filename> package, as illustrated in this example.  If you
-put <literal>\usepackage{tablefootnote}</literal> in the preamble and use the code
-shown then the footnote appears at the bottom and is numbered in
-sequence with other footnotes.
+<para>For a floating <literal>table</literal> environment (see <link linkend="table">table</link>), use the
+<filename>tablefootnote</filename> package.
 </para>
-<screen>\begin{table}
+<screen>\usepackage{tablefootnote}  % in preamble
+   ...
+\begin{table}
   \centering
      \begin{tabular}{l|l}
      \textsc{Date}  &\textsc{Campaign} \\ \hline 
      1862           &Fort Donelson \\ 
      1863           &Vicksburg     \\  
-     1865           &Army of Northern Virginia\footnote{Ending the war.}
+     1865           &Army of Northern Virginia\tablefootnote{%
+                      Ending the war.}
      \end{tabular}
     \caption{Forces captured by US Grant}
 \end{table}
 </screen>
-
-</sect1>
-<sect1 label="11.5" id="Footnotes-in-section-headings">
-<title>Footnotes in section headings</title>
-
-<indexterm role="cp"><primary>footnotes, in section headings</primary></indexterm>
-<indexterm role="cp"><primary>table of contents, avoiding footnotes</primary></indexterm>
-<para>Putting a footnote in a section heading, as in:
+<para>The footnote appears at the page bottom and is numbered in sequence with
+other footnotes.
 </para>
-<screen>\section{Full sets\protect\footnote{This material due to ...}}
-</screen>
-<indexterm role="cp"><primary>package, <literal>footmisc</literal></primary></indexterm>
-<indexterm role="cp"><primary><literal>footmisc</literal> package</primary></indexterm>
 
-<indexterm role="cp"><primary><literal>stable</literal> option to <literal>footmisc</literal> package</primary></indexterm>
-<para>causes the footnote to appear at the bottom of the page where the
-section starts, as usual, but also at the bottom of the table of
-contents, where it is not likely to be desired.  To have it not appear
-on the table of contents use the package <filename>footmisc</filename> with the
-<literal>stable</literal> option.
-</para>
-<screen>\usepackage[stable]{footmisc}
-...
-\begin{document}
-...
-\section{Full sets\footnote{This material due to ...}}
-</screen>
-<para>Note that the <literal>\protect</literal> is gone; including it would cause the
-footnote to reappear on the table of contents.
-</para>
-
 </sect1>
 <sect1 label="11.6" id="Footnotes-of-footnotes">
 <title>Footnotes of footnotes</title>
 
+<indexterm role="cp"><primary>footnote, of a footnote</primary></indexterm>
+
+<indexterm role="cp"><primary>package, <literal>bigfoot</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>bigfoot</literal> package</primary></indexterm>
+
 <para>Particularly in the humanities, authors can have multiple classes of
 footnotes, including having footnotes of footnotes.  The package
 <filename>bigfoot</filename> extends &latex;’s default footnote mechanism in many
 ways, including allow these two, as in this example.
 </para>
-<screen>\usepackage{bigfoot}
+<screen>\usepackage{bigfoot}    % in preamble
 \DeclareNewFootnote{Default}
 \DeclareNewFootnote{from}[alph]   % create class \footnotefrom{}
  ...
-\begin{document}
-...
 The third theorem is a partial converse of the 
-second.\footnotefrom{First noted in Wilson.\footnote{Second edition only.}}
-...
+second.\footnotefrom{%
+  First noted in Wilson.\footnote{Second edition only.}}
 </screen>
 
 </sect1>
-<sect1 label="11.7" id="Multiple-reference-to-footnotes">
-<title>Multiple references to footnotes</title>
-
-<para>You can refer to a single footnote more than once.  This example
-uses the package <filename>cleverref</filename>.
-</para>
-<!-- from SE user Jake http://tex.stackexchange.com/a/10116/339 -->
-<screen>\usepackage{cleveref}[2012/02/15]   % this version of package or later 
-\crefformat{footnote}{#2\footnotemark[#1]#3}
-...
-\begin{document}
-...
-The theorem is from Evers.\footnote{\label{fn:TE}Tinker and Evers, 1994.}
-The corollary is from Chance.\footnote{Evers and Chance, 1990.}
-But the key lemma is from Tinker.\cref{fn:TE}
-...
-</screen>
-<para>This solution will work with the package <filename>hyperref</filename>.
-See <link linkend="_005cfootnotemark">\footnotemark</link> for a simpler solution in the common case
-of multiple authors with the same affiliation.
-</para>
-
-</sect1>
-<sect1 label="11.8" id="Footnote-parameters">
-<title>Footnote parameters</title>
-
-<indexterm role="cp"><primary>footnote parameters</primary></indexterm>
-<indexterm role="cp"><primary>parameters, for footnotes</primary></indexterm>
-
-<variablelist><varlistentry><term><indexterm role="fn"><primary>\footnoterule</primary></indexterm><literal>\footnoterule</literal>
-</term><listitem><para>Produces the rule separating the main text on a page from the page’s
-footnotes.  Default dimensions: <literal>0.4pt</literal> thick (or wide), and
-<literal>0.4\columnwidth</literal> long in the standard document classes (except
-<literal>slides</literal>, where it does not appear).
-</para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\footnotesep</primary></indexterm><literal>\footnotesep</literal>
-</term><listitem><para>The height of the strut placed at the beginning of the footnote.  By
-default, this is set to the normal strut for <literal>\footnotesize</literal>
-fonts (see <link linkend="Font-sizes">Font sizes</link>), therefore there is no extra space between
-footnotes.  This is ‘<literal>6.65pt</literal>’ for ‘<literal>10pt</literal>’, ‘<literal>7.7pt</literal>’ for
-‘<literal>11pt</literal>’, and ‘<literal>8.4pt</literal>’ for ‘<literal>12pt</literal>’.
-</para>
-</listitem></varlistentry></variablelist>
-
-</sect1>
 </chapter>
 <chapter label="12" id="Definitions">
 <title>Definitions</title>
@@ -6043,11 +7792,8 @@
 
 <para>&latex; has support for making new commands of many different kinds.
 </para>
-<!-- xx everything in this chapter needs examples. -->
-<!-- xx Add DeclareRobustCommand (see clsguide.pdf) -->
 
 
-
 <sect1 label="12.1" id="_005cnewcommand-_0026-_005crenewcommand">
 <title><literal>\newcommand</literal> & <literal>\renewcommand</literal></title>
 
@@ -6057,101 +7803,136 @@
 <indexterm role="cp"><primary>defining a new command</primary></indexterm>
 <indexterm role="cp"><primary>new commands, defining</primary></indexterm>
 
-<para><literal>\newcommand</literal> and <literal>\renewcommand</literal> define and redefine a
-command, respectively.  Synopses:
+<para>Synopses, one of:
 </para>
-<screen>  \newcommand{\<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>optargdefault</replaceable>]{<replaceable>defn</replaceable>}
-  \newcommand*{\<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>optargdefault</replaceable>]{<replaceable>defn</replaceable>}
+<screen>\newcommand{\<replaceable>cmd</replaceable>}{<replaceable>defn</replaceable>}
+\newcommand{\<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>]{<replaceable>defn</replaceable>}
+\newcommand{\<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>optargdefault</replaceable>]{<replaceable>defn</replaceable>}
+\newcommand*{\<replaceable>cmd</replaceable>}{<replaceable>defn</replaceable>}
+\newcommand*{\<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>]{<replaceable>defn</replaceable>}
+\newcommand*{\<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>optargdefault</replaceable>]{<replaceable>defn</replaceable>}
+</screen>
+<para>or one of these.
+</para>
+<screen>\renewcommand{\<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>]{<replaceable>defn</replaceable>}
+\renewcommand{\<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>]{<replaceable>defn</replaceable>}
 \renewcommand{\<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>optargdefault</replaceable>]{<replaceable>defn</replaceable>}
+\renewcommand*{\<replaceable>cmd</replaceable>}{<replaceable>defn</replaceable>}
+\renewcommand*{\<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>]{<replaceable>defn</replaceable>}
 \renewcommand*{\<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>optargdefault</replaceable>]{<replaceable>defn</replaceable>}
 </screen>
+<para>Define or redefine a command.  See also the discussion of
+<literal>\DeclareRobustCommand</literal> in <link linkend="Class-and-package-commands">Class and package commands</link>.
 <indexterm role="cp"><primary>starred form, defining new commands</primary></indexterm>
 <indexterm role="cp"><primary>*-form, defining new commands</primary></indexterm>
-<para>The starred form of these two commands requires that the arguments not
-contain multiple paragraphs of text (not <literal>\long</literal>, in plain &tex;
-terms).
+The starred form of these two requires that the arguments not contain
+multiple paragraphs of text (in plain &tex; terms that it not be
+<literal>\long</literal>).
 </para>
+<para>These are the parameters:
+</para>
 <variablelist><varlistentry><term><replaceable>cmd</replaceable>
-</term><listitem><para>Required; <literal>\<replaceable>cmd</replaceable></literal> is the command name.  For <literal>\newcommand</literal>, it
-must not be already defined and must not begin with <literal>\end</literal>.  For
-<literal>\renewcommand</literal>, it must already be defined.
+</term><listitem>
+<para>Required; the command name.  It must begin with a backslash, <literal>\</literal>,
+and must not begin with the four letter string <literal>\end</literal>.  For
+<literal>\newcommand</literal>, it must not be already defined.  For
+<literal>\renewcommand</literal>, this name must already be defined.
 </para>
 </listitem></varlistentry><varlistentry><term><replaceable>nargs</replaceable>
 </term><listitem><para>Optional; an integer from 0 to 9, specifying the number of arguments
-that the command can take, including any optional argument.  If this
-argument is not present, the default is for the command to have no
-arguments.  When redefining a command, the new version can have a
+that the command takes, including any optional argument.  Omitting this
+argument is the same as specifying 0, meaning that the command has no
+arguments.  If you redefine a command, the new version can have a
 different number of arguments than the old version.
 </para>
 </listitem></varlistentry><varlistentry><term><replaceable>optargdefault</replaceable>
-</term><listitem><para>Optional; if this argument is present then the first argument of defined
-command <literal>\<replaceable>cmd</replaceable></literal> is optional, with default value <replaceable>optargdefault</replaceable>
+</term><listitem><para>Optional; if this argument is present then the first argument of
+<literal>\<replaceable>cmd</replaceable></literal> is optional, with default value <replaceable>optargdefault</replaceable>
 (which may be the empty string).  If this argument is not present then
 <literal>\<replaceable>cmd</replaceable></literal> does not take an optional argument.
 </para>
 <indexterm role="cp"><primary>positional parameter</primary></indexterm>
-<para>That is, if <literal>\<replaceable>cmd</replaceable></literal> is used with square brackets following,
-as in <literal>\<replaceable>cmd</replaceable>[<replaceable>myval</replaceable>]</literal>, then within <replaceable>defn</replaceable> the first
-<firstterm>positional parameter</firstterm> <literal>#1</literal> expands <replaceable>myval</replaceable>.  On the
-other hand, if <literal>\<replaceable>cmd</replaceable></literal> is called without square brackets
-following, then within <replaceable>defn</replaceable> the positional parameter <literal>#1</literal>
-expands to the default <replaceable>optargdefault</replaceable>.  In either case, any
-required arguments will be referred to starting with <literal>#2</literal>.
+<para>That is, if <literal>\<replaceable>cmd</replaceable></literal> is used with square brackets, as in
+<literal>\<replaceable>cmd</replaceable>[<replaceable>optval</replaceable>]{...}...</literal>, then within <replaceable>defn</replaceable> the
+parameter <literal>#1</literal> is set to the value of <replaceable>optval</replaceable>.  On the
+other hand, if <literal>\<replaceable>cmd</replaceable></literal> is called without the square brackets
+then within <replaceable>defn</replaceable> the parameter <literal>#1</literal> is set to the value of
+<replaceable>optargdefault</replaceable>.  In either case, the required arguments start with
+<literal>#2</literal>.
 </para>
-<para>Omitting <literal>[<replaceable>myval</replaceable>]</literal> in a call is different from having the
-square brackets with no contents, as in <literal>[]</literal>.  The former results
-in <literal>#1</literal> expanding to <replaceable>optargdefault</replaceable>; the latter results in
-<literal>#1</literal> expanding to the empty string.
+<para>Omitting <literal>[<replaceable>optargdefault</replaceable>]</literal> is different from having the
+square brackets with no contents, as in <literal>[]</literal>.  The former sets
+<literal>#1</literal> to the value of <replaceable>optargdefault</replaceable>; the latter sets <literal>#1</literal>
+to the empty string.
 </para>
 </listitem></varlistentry><varlistentry><term><replaceable>defn</replaceable>
-</term><listitem><para>The text to be substituted for every occurrence of <literal>\<replaceable>cmd</replaceable></literal>; the
-positional parameter <literal>#<replaceable>n</replaceable></literal> in <replaceable>defn</replaceable> is replaced by
-the text of the <replaceable>n</replaceable>th argument.
+</term><listitem><para>Required; the text to be substituted for every occurrence of
+<literal>\<replaceable>cmd</replaceable></literal>. The parameters <literal>#1</literal>, <literal>#2</literal>,
+... <literal>#<replaceable>nargs</replaceable></literal> are replaced by the values that you supply when
+you call the command (or by the default value if there is an optional
+argument and you don’t exercise the option).
 </para>
 </listitem></varlistentry></variablelist>
 <para>&tex; ignores spaces in the source following an alphabetic control
 sequence, as in ‘<literal>\cmd </literal>’.  If you actually want a space there, one
-solution is to type <literal>{}</literal> after the command (‘<literal>\cmd{} </literal>’;
+solution is to type <literal>{}</literal> after the command (‘<literal>\cmd{} </literal>’, and
 another solution is to use an explicit control space (‘<literal>\cmd\ </literal>’).
 </para>
 <para>A simple example of defining a new command:
-<literal>\newcommand{\RS}{Robin Smith}</literal> results in
-<literal>\RS</literal> being replaced by the longer text.
-</para>
-<para>Redefining an existing command is similar:
+<literal>\newcommand{\RS}{Robin Smith}</literal> results in <literal>\RS</literal> being
+replaced by the longer text.  Redefining an existing command is similar:
 <literal>\renewcommand{\qedsymbol}{{\small QED}}</literal>.
 </para>
-<para>Here’s a command definition with one required argument:
+<para>If you try to define a command and the name has already been used then
+you get something like ‘<literal>LaTeX Error: Command \fred already
+defined. Or name \end... illegal, see p.192 of the manual</literal>’.  If you try
+to redefine a command and the name has not yet been used then you get
+something like ‘<literal>LaTeX Error: \hank undefined</literal>’.
 </para>
-<screen>\newcommand{\defref}[1]{Definition~\ref{#1}}
+<para>Here the first command definition has no arguments, and the second has
+one required argument.
+</para>
+<screen>\newcommand{\student}{Ms~O'Leary}
+\newcommand{\defref}[1]{Definition~\ref{#1}}
 </screen>
-<para>Then, <literal>\defref{def:basis}</literal> expands to
-<literal>Definition~\ref{def:basis}</literal>, which will ultimately expand to
+<para>Use the first as in <literal>I highly recommend \student{} to you</literal>.  The
+second has a variable, so that <literal>\defref{def:basis}</literal> expands to
+<literal>Definition~\ref{def:basis}</literal>, which ultimately expands to
 something like ‘<literal>Definition~3.14</literal>’.
 </para>
-<para>An example with two required arguments:
+<para>Similarly, but with two required arguments:
 <literal>\newcommand{\nbym}[2]{$#1 \times #2$}</literal> is invoked as
 <literal>\nbym{2}{k}</literal>.
 </para>
-<para>An example with an optional argument:
+<para>This example has an optional argument.
 </para>
 <screen>\newcommand{\salutation}[1][Sir or Madam]{Dear #1:}
 </screen>
-<para>Then, <literal>\salutation</literal> gives ‘<literal>Dear Sir or Madam:</literal>’ while
+<para>Then <literal>\salutation</literal> gives ‘<literal>Dear Sir or Madam:</literal>’ while
 <literal>\salutation[John]</literal> gives ‘<literal>Dear John:</literal>’.  And
 <literal>\salutation[]</literal> gives ‘<literal>Dear :</literal>’.
 </para>
-<para>The braces around <replaceable>defn</replaceable> do not define a group, that is, they do
-not delimit the scope of the result of expanding <replaceable>defn</replaceable>.  So
-<literal>\newcommand{\shipname}[1]{\it #1}</literal> is problematic; in this
-sentence,
+<para>This example has an optional argument and two required arguments.
 </para>
+<screen>\newcommand{\lawyers}[3][company]{#2, #3, and~#1}
+I employ \lawyers[Howe]{Dewey}{Cheatem}.
+</screen>
+<para>The output is ‘<literal>I employ Dewey, Cheatem, and Howe</literal>’.  The optional
+argument, the <literal>Howe</literal>, is associated with <literal>#1</literal>, while
+<literal>Dewey</literal> and <literal>Cheatem</literal> are associated with <literal>#2</literal>
+and <literal>#3</literal>.  Because of the optional argument,
+<literal>\lawyers{Dewey}{Cheatem}</literal> will give the output ‘<literal>I employ
+Dewey, Cheatem, and company</literal>’.
+</para>
+<para>The braces around <replaceable>defn</replaceable> do not define a group, that is, they do not
+delimit the scope of the result of expanding <replaceable>defn</replaceable>.  For example,
+with <literal>\newcommand{\shipname}[1]{\it #1}</literal>, in this sentence,
+</para>
 <screen>The \shipname{Monitor} met the \shipname{Merrimac}.
 </screen>
-<para>the words ‘<literal>met the</literal>’ would incorrectly be in italics.  Another
-pair of braces in the definition is needed, like this:
-<literal>\newcommand{\shipname}[1]{{\it #1}}</literal>.  Those braces are
-part of the definition and thus do define a group.
+<para>the words ‘<literal>met the</literal>’ would incorrectly be in italics.  The solution
+is to put another pair of braces inside the definition:
+<literal>\newcommand{\shipname}[1]{{\it #1}}</literal>.
 </para>
 
 </sect1>
@@ -6163,18 +7944,31 @@
 <indexterm role="cp"><primary>defining a new command</primary></indexterm>
 <indexterm role="cp"><primary>new commands, defining</primary></indexterm>
 
-<para>Defines a command, as long as no command of this name already exists.
-Synopses:
+<para>Synopses, one of:
 </para>
-<screen>\providecommand{<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>optargdefault</replaceable>]{<replaceable>defn</replaceable>}
+<screen>\providecommand{<replaceable>cmd</replaceable>}{<replaceable>defn</replaceable>}
+\providecommand{<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>]{<replaceable>defn</replaceable>}
+\providecommand{<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>optargdefault</replaceable>]{<replaceable>defn</replaceable>}
+\providecommand*{<replaceable>cmd</replaceable>}{<replaceable>defn</replaceable>}
+\providecommand*{<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>]{<replaceable>defn</replaceable>}
 \providecommand*{<replaceable>cmd</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>optargdefault</replaceable>]{<replaceable>defn</replaceable>}
 </screen>
-<para>If no command of this name already exists then this has the same effect
-as <literal>\newcommand</literal> (see <link linkend="_005cnewcommand-_0026-_005crenewcommand">\newcommand & \renewcommand</link>).  If a
-command of this name already exists then this definition does nothing.
-This is particularly useful in a style file, or other file that may be
-loaded more than once.
+<para>Defines a command, as long as no command of this name already exists.
+If no command of this name already exists then this has the same effect
+as <literal>\newcommand</literal>.  If a command of this name already exists then
+this definition does nothing.  This is particularly useful in a file
+that may be loaded more than once, such as a style file.
+See <link linkend="_005cnewcommand-_0026-_005crenewcommand">\newcommand & \renewcommand</link> for the description of the arguments.
 </para>
+<para>This example
+</para>
+<screen>\providecommand{\myaffiliation}{Saint Michael's College}
+\providecommand{\myaffiliation}{Saint Michael's College}
+From \myaffiliation.
+</screen>
+<para>outputs ‘<literal>From Saint Michael's College</literal>’.  Unlike <literal>\newcommand</literal>,
+the repeated use of <literal>\providecommand</literal> does not give an error.
+</para>
 
 </sect1>
 <sect1 label="12.3" id="_005cnewcounter">
@@ -6188,27 +7982,46 @@
 <screen>\newcounter{<replaceable>countername</replaceable>}
 \newcounter{<replaceable>countername</replaceable>}[<replaceable>supercounter</replaceable>]
 </screen>
-<para>Globally defines a new counter named <replaceable>countername</replaceable> and initialize
-the new counter to zero.
+<para>Globally defines a new counter named <replaceable>countername</replaceable> and initialize it
+to zero (see <link linkend="Counters">Counters</link>).
 </para>
-<para>The name <replaceable>countername</replaceable> must consists of letters only, and does not
+<para>The name <replaceable>countername</replaceable> must consist of letters only. It does not
 begin with a backslash.  This name must not already be in use by another
 counter.
 </para>
-<para>When you use the optional argument <literal>[<replaceable>supercounter</replaceable>]</literal> then
-<replaceable>countername</replaceable> will be numbered within, or subsidiary to, the
-existing counter <replaceable>supercounter</replaceable>.  For example, ordinarily
-<literal>subsection</literal> is numbered within <literal>section</literal> so that any time
-<replaceable>supercounter</replaceable> is incremented with <literal>\stepcounter</literal>
+<para>When you use the optional argument <literal>[<replaceable>supercounter</replaceable>]</literal> then the
+counter <replaceable>countername</replaceable> will be reset to zero whenever
+<replaceable>supercounter</replaceable> is incremented.  For example, ordinarily
+<literal>subsection</literal> is numbered within <literal>section</literal> so that any time you
+increment <replaceable>section</replaceable>, either with <literal>\stepcounter</literal>
 (see <link linkend="_005cstepcounter">\stepcounter</link>) or <literal>\refstepcounter</literal>
-(see <link linkend="_005crefstepcounter">\refstepcounter</link>) then <replaceable>countername</replaceable> is reset to zero.
+(see <link linkend="_005crefstepcounter">\refstepcounter</link>), then &latex; will reset <replaceable>subsection</replaceable> to
+zero.
 </para>
-<para>See <link linkend="Counters">Counters</link>, for more information about counters.
+<para>This example
 </para>
+<screen>\newcounter{asuper}  \setcounter{asuper}{1}
+\newcounter{asub}[asuper] \setcounter{asub}{3}   % Note `asuper'
+The value of asuper is \arabic{asuper} and of asub is \arabic{asub}.
+\stepcounter{asuper}
+Now asuper is \arabic{asuper} while asub is \arabic{asub}.
+</screen>
+<para>produces ‘<literal>The value of asuper is 1 and that of asub is 3</literal>’ and
+‘<literal>Now asuper is 2 while asub is 0</literal>’.
+</para>
+<para>If the counter already exists, for instance by entering <literal>asuper</literal>
+twice, then you get something like ‘<literal>LaTeX Error: Command \c at asuper
+already defined.  Or name \end... illegal, see p.192 of the manual.</literal>’.
+</para>
+<para>If you use the optional argument then the super counter must already
+exist. Entering <literal>\newcounter{jh}[lh]</literal> when <literal>lh</literal> is not a
+defined counter will get you ‘<literal>LaTeX Error: No counter 'lh'
+defined.</literal>’
+</para>
 
 </sect1>
 <sect1 label="12.4" id="_005cnewlength">
-<title><literal>\newlength</literal>: Allocating a length</title>
+<title><literal>\newlength</literal></title>
 
 <indexterm role="fn"><primary>\newlength</primary></indexterm>
 <indexterm role="cp"><primary>lengths, allocating new</primary></indexterm>
@@ -6216,40 +8029,58 @@
 <indexterm role="cp"><primary>skip register, plain &tex;</primary></indexterm>
 <indexterm role="cp"><primary>glue register, plain &tex;</primary></indexterm>
 
-<para>Allocate a new <firstterm>length</firstterm> register.  Synopsis:
+<para>Synopsis:
 </para>
-<screen>\newlength{\<replaceable>arg</replaceable>}
+<screen>\newlength{<replaceable>arg</replaceable>}
 </screen>
-<para>This command takes one required argument, which must begin with a
-backslash (‘<literal>\</literal>’).  It creates a new length register named
-<literal>\<replaceable>arg</replaceable></literal>, which is a place to hold (rubber) lengths such as
-<literal>1in plus.2in minus.1in</literal> (what plain &tex; calls a <literal>skip</literal>
-register).  The register gets an initial value of zero.  The control
-sequence <literal>\<replaceable>arg</replaceable></literal> must not already be defined.
+<para>Allocate a new length register (see <link linkend="Lengths">Lengths</link>).  The required argument
+<replaceable>arg</replaceable> must begin with a backslash, <literal>\</literal>.  The new register holds
+rubber lengths such as <literal>72.27pt</literal> or <literal>1in plus.2in minus.1in</literal>
+(a &latex; length register is what plain &tex; calls a <literal>skip</literal>
+register).  The initial value is zero.  The control sequence
+<literal>\<replaceable>arg</replaceable></literal> must not be already defined.
 </para>
-<para>See <link linkend="Lengths">Lengths</link>, for more about lengths.
+<para>An example:
 </para>
+<screen>\newlength{\graphichgt}
+</screen>
+<para>If you forget the backslash then you get ‘<literal>Missing control sequence
+inserted</literal>’.  If the command sequence already exists then you get
+something like ‘<literal>LaTeX Error: Command \graphichgt already defined.
+Or name \end... illegal, see p.192 of the manual</literal>’.
+</para>
 
 </sect1>
 <sect1 label="12.5" id="_005cnewsavebox">
-<title><literal>\newsavebox</literal>: Allocating a box</title>
+<title><literal>\newsavebox</literal></title>
 
 <indexterm role="fn"><primary>\newsavebox</primary></indexterm>
 <indexterm role="cp"><primary>box, allocating new</primary></indexterm>
 
-<para>Allocate a “bin” for holding a box.  Synopsis:
+<para>Synopsis:
 </para>
-<screen>\newsavebox{\<replaceable>cmd</replaceable>}
+<screen>\newsavebox{<replaceable>cmd</replaceable>}
 </screen>
-<para>Defines <literal>\<replaceable>cmd</replaceable></literal> to refer to a new bin for storing boxes.
-Such a box is for holding typeset material, to use multiple times
-(see <link linkend="Boxes">Boxes</link>) or to measure or manipulate.  The name
-<literal>\<replaceable>cmd</replaceable></literal> must start with a backslash (‘<literal>\</literal>’), and must not
-be already defined.
+<para>Define <literal>\<replaceable>cmd</replaceable></literal> to refer to a new “bin” for storing boxes.
+Such a box is for holding typeset material, to use multiple times or to
+measure or manipulate (see <link linkend="Boxes">Boxes</link>).  The required bin name
+<literal><replaceable>cmd</replaceable></literal> must start with a backslash, <literal>\</literal>, and must not
+already be defined.  This command is fragile (see <link linkend="_005cprotect">\protect</link>).
 </para>
-<para>The allocation of a box is global.  This command is fragile
-(see <link linkend="_005cprotect">\protect</link>).
+<para>The first line here sets you up to save the material for later use. 
 </para>
+<screen>\newsavebox{\logobox}
+\savebox{\logobox}{LoGo}
+Our logo is \usebox{\logobox}. 
+</screen>
+<para>The output is ‘<literal>Our logo is LoGo</literal>’.
+</para>
+<para>If there is an already defined bin then you get something like
+‘<literal>LaTeX Error: Command \logobox already defined. Or name
+\end... illegal, see p.192 of the manual</literal>’.
+</para>
+<para>The allocation of a box is global.
+</para>
 
 </sect1>
 <sect1 label="12.6" id="_005cnewenvironment-_0026-_005crenewenvironment">
@@ -6261,23 +8092,36 @@
 <indexterm role="cp"><primary>defining new environments</primary></indexterm>
 <indexterm role="cp"><primary>redefining environments</primary></indexterm>
 
-<para>These commands define or redefine an environment <replaceable>env</replaceable>, that is,
-<literal>\begin{<replaceable>env</replaceable>} <replaceable>body</replaceable> \end{<replaceable>env</replaceable>}</literal>.  Synopses:
+<para>Synopses, one of:
 </para>
-<screen>   \newenvironment{<replaceable>env</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>optargdefault</replaceable>]{<replaceable>begdefn</replaceable>}{<replaceable>enddefn</replaceable>}
-  \newenvironment*{<replaceable>env</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>optargdefault</replaceable>]{<replaceable>begdefn</replaceable>}{<replaceable>enddefn</replaceable>}
- \renewenvironment{<replaceable>env</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>optargdefault</replaceable>]{<replaceable>begdefn</replaceable>}{<replaceable>enddefn</replaceable>}
-\renewenvironment*{<replaceable>env</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>optargdefault</replaceable>]{<replaceable>begdefn</replaceable>}{<replaceable>enddefn</replaceable>}
+<screen>\newenvironment{<replaceable>env</replaceable>}{<replaceable>begdef</replaceable>}{<replaceable>enddef</replaceable>}
+\newenvironment{<replaceable>env</replaceable>}[<replaceable>nargs</replaceable>]{<replaceable>begdef</replaceable>}{<replaceable>enddef</replaceable>}
+\newenvironment{<replaceable>env</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>optargdefault</replaceable>]{<replaceable>begdef</replaceable>}{<replaceable>enddef</replaceable>}
+\newenvironment*{<replaceable>env</replaceable>}{<replaceable>begdef</replaceable>}{<replaceable>enddef</replaceable>}
+\newenvironment*{<replaceable>env</replaceable>}[<replaceable>nargs</replaceable>]{<replaceable>begdef</replaceable>}{<replaceable>enddef</replaceable>}
+\newenvironment*{<replaceable>env</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>optargdefault</replaceable>]{<replaceable>begdef</replaceable>}{<replaceable>enddef</replaceable>}
 </screen>
+<para>or one of these.
+</para>
+<screen>\renewenvironment{<replaceable>env</replaceable>}{<replaceable>begdef</replaceable>}{<replaceable>enddef</replaceable>}
+\renewenvironment{<replaceable>env</replaceable>}[<replaceable>nargs</replaceable>]{<replaceable>begdef</replaceable>}{<replaceable>enddef</replaceable>}
+\renewenvironment{<replaceable>env</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>optargdefault</replaceable>]{<replaceable>begdef</replaceable>}{<replaceable>enddef</replaceable>}
+\renewenvironment*{<replaceable>env</replaceable>}{<replaceable>begdef</replaceable>}{<replaceable>enddef</replaceable>}
+\renewenvironment*{<replaceable>env</replaceable>}[<replaceable>nargs</replaceable>]{<replaceable>begdef</replaceable>}{<replaceable>enddef</replaceable>}
+\renewenvironment*{<replaceable>env</replaceable>}[<replaceable>nargs</replaceable>][<replaceable>optargdefault</replaceable>]{<replaceable>begdef</replaceable>}{<replaceable>enddef</replaceable>}
+</screen>
+<para>Define or redefine the environment <replaceable>env</replaceable>, that is, create the
+construct <literal>\begin{<replaceable>env</replaceable>} ... <replaceable>body</replaceable> ... \end{<replaceable>env</replaceable>}</literal>.
+</para>
 <indexterm role="cp"><primary><literal>*</literal>-form of environment commands</primary></indexterm>
 <para>The starred form of these commands requires that the arguments not
-contain multiple paragraphs of text.  The body of these environments can
-still contain multiple paragraphs.
+contain multiple paragraphs of text.  However, the body of these
+environments can contain multiple paragraphs.
 </para>
 <variablelist><varlistentry><term><replaceable>env</replaceable>
 </term><listitem><para>Required; the environment name.  It consists only of letters or the
-<literal>*</literal> character, and thus does not begin with backslash
-(<literal>\</literal>).  It must not begin with the string <literal>end</literal>.  For
+<literal>*</literal> character, and thus does not begin with backslash, <literal>\</literal>.
+It must not begin with the string <literal>end</literal>.  For
 <literal>\newenvironment</literal>, the name <replaceable>env</replaceable> must not be the name of an
 already existing environment, and also the command <literal>\<replaceable>env</replaceable></literal>
 must be undefined.  For <literal>\renewenvironment</literal>, <replaceable>env</replaceable> must be the
@@ -6285,54 +8129,60 @@
 </para>
 </listitem></varlistentry><varlistentry><term><replaceable>nargs</replaceable>
 </term><listitem><para>Optional; an integer from 0 to 9 denoting the number of arguments of
-that the environment will take.  When the environment is used these
+that the environment takes.  When you use the environment these
 arguments appear after the <literal>\begin</literal>, as in
-<literal>\begin{<replaceable>env</replaceable>}{<replaceable>arg1</replaceable>}…{<replaceable>argn</replaceable>}</literal>.  If this
-argument is not present then the default is for the environment to have
-no arguments.  When redefining an environment, the new version can have
-a different number of arguments than the old version.
+<literal>\begin{<replaceable>env</replaceable>}{<replaceable>arg1</replaceable>} ... {<replaceable>argn</replaceable>}</literal>.  Omitting
+this is equivalent to setting it to 0; the environment will have no
+arguments.  When redefining an environment, the new version can have a
+different number of arguments than the old version.
 </para>
 </listitem></varlistentry><varlistentry><term><replaceable>optargdefault</replaceable>
-</term><listitem><para>Optional; if this argument is present then the first argument of the
-defined environment is optional, with default value <replaceable>optargdefault</replaceable>
-(which may be the empty string).  If this argument is not present then
-the environment does not take an optional argument.
+</term><listitem><para>Optional; if this is present then the first argument of the defined
+environment is optional, with default value <replaceable>optargdefault</replaceable> (which
+may be the empty string).  If this is not in the definition then the
+environment does not take an optional argument.
 </para>
-<para>That is, when <literal>[<replaceable>optargdefault</replaceable>]</literal> is present in the
-environment definition, if <literal>\begin{<replaceable>env</replaceable>}</literal> is used with
-square brackets following, as in
-<literal>\begin{<replaceable>env</replaceable>}[<replaceable>myval</replaceable>]</literal>, then, within <replaceable>begdefn</replaceable>,
-the positional parameter <literal>#1</literal> expands to <replaceable>myval</replaceable>.  If
-<literal>\begin{<replaceable>env</replaceable>}</literal> is called without square brackets
-following, then, within within <replaceable>begdefn</replaceable>, the positional parameter
-<literal>#1</literal> expands to the default <replaceable>optargdefault</replaceable>.  In either case,
-any required arguments will be referred to starting with <literal>#2</literal>.
+<para>That is, when <replaceable>optargdefault</replaceable> is present in the definition of the
+environment then you can start the environment with square brackets, as
+in <literal>\begin{<replaceable>env</replaceable>}[<replaceable>optval</replaceable>]{...} ... \end{<replaceable>env</replaceable>}</literal>.
+In this case, within <replaceable>begdefn</replaceable> the parameter <literal>#1</literal> is set to the
+value of <replaceable>optval</replaceable>.  If you call <literal>\begin{<replaceable>env</replaceable>}</literal> without
+square brackets, then within <replaceable>begdefn</replaceable> the parameter <literal>#1</literal> is
+set to the value of the default <replaceable>optargdefault</replaceable>.  In either case,
+any required arguments start with <literal>#2</literal>.
 </para>
-<para>Omitting <literal>[<replaceable>myval</replaceable>]</literal> in the call is different from having the
+<para>Omitting <literal>[<replaceable>myval</replaceable>]</literal> in the call is different than having the
 square brackets with no contents, as in <literal>[]</literal>.  The former results
 in <literal>#1</literal> expanding to <replaceable>optargdefault</replaceable>; the latter results in
 <literal>#1</literal> expanding to the empty string.
 </para>
-</listitem></varlistentry><varlistentry><term><replaceable>begdefn</replaceable>
+</listitem></varlistentry><varlistentry><term><replaceable>begdef</replaceable>
 </term><listitem><para>Required; the text expanded at every occurrence of
-<literal>\begin{<replaceable>env</replaceable>}</literal>.  Within <replaceable>begdef</replaceable>, the <replaceable>n</replaceable>th
-positional parameter (i.e., <literal>#<replaceable>n</replaceable></literal>) is replaced by the text
-of the <replaceable>n</replaceable>th argument.
+<literal>\begin{<replaceable>env</replaceable>}</literal>.  Within <replaceable>begdef</replaceable>, the parameters
+<literal>#1</literal>, <literal>#2</literal>, ... <literal>#<replaceable>nargs</replaceable></literal>, are replaced by the
+values that you supply when you call the environment; see the examples
+below.
 </para>
-</listitem></varlistentry><varlistentry><term><replaceable>enddefn</replaceable>
+</listitem></varlistentry><varlistentry><term><replaceable>enddef</replaceable>
 </term><listitem><para>Required; the text expanded at every occurrence of
-<literal>\end{<replaceable>env</replaceable>}</literal>.  This may not contain any positional
-parameters, so <literal>#<replaceable>n</replaceable></literal> cannot be used here (but see the final
+<literal>\end{<replaceable>env</replaceable>}</literal>.  This may not contain any parameters, that is,
+you cannot use <literal>#1</literal>, <literal>#2</literal>, etc., here (but see the final
 example below).
 </para>
 </listitem></varlistentry></variablelist>
-<para>All environments, that is to say the <replaceable>begdefn</replaceable> code, the environment
-body and the <replaceable>enddefn</replaceable> code, are processed within a group.  Thus, in
+<para>All environments, that is to say the <replaceable>begdef</replaceable> code, the environment
+body, and the <replaceable>enddef</replaceable> code, are processed within a group.  Thus, in
 the first example below, the effect of the <literal>\small</literal> is limited to
 the quote and does not extend to material following the environment.
 </para>
+<para>If you try to define an environment and the name has already been used
+then you get something like ‘<literal>LaTeX Error: Command \fred already
+defined. Or name \end... illegal, see p.192 of the manual</literal>’.  If you try
+to redefine an environment and the name has not yet been used then you
+get something like ‘<literal>LaTeX Error: Environment hank undefined.</literal>’.
+</para>
 <para>This example gives an environment like &latex;’s <literal>quotation</literal>
-except that it will be set in smaller type:
+except that it will be set in smaller type.
 </para>
 <screen>\newenvironment{smallquote}{%
   \small\begin{quotation}
@@ -6340,9 +8190,17 @@
   \end{quotation}
 }
 </screen>
-<para>This one shows the use of arguments; it gives a quotation environment
-that cites the author:
+<para>This has an argument, which is set in boldface at the start of a
+paragraph.
 </para>
+<screen>\newenvironment{point}[1]{%
+  \noindent\textbf{#1}
+}{%
+}
+</screen>
+<para>This one shows the use of a optional argument; it gives a quotation
+environment that cites the author.
+</para>
 <screen>\newenvironment{citequote}[1][Shakespeare]{%
   \begin{quotation}
   \noindent\textit{#1}: 
@@ -6350,15 +8208,15 @@
   \end{quotation}
 }
 </screen>
-<para>The author’s name is optional, and defaults to ‘<literal>Shakespeare</literal>’.
-In the document, use the environment like this:
+<para>The author’s name is optional, and defaults to ‘<literal>Shakespeare</literal>’.  In
+the document, use the environment like this.
 </para>
 <screen>\begin{citequote}[Lincoln]
   ...
 \end{citequote}
 </screen>
 <para>The final example shows how to save the value of an argument to use in 
-<replaceable>enddefn</replaceable>, in this case in a box (see <link linkend="_005csbox">\sbox</link>):
+<replaceable>enddef</replaceable>, in this case in a box (see <link linkend="_005csbox-_0026-_005csavebox">\sbox & \savebox</link>).
 </para>
 <screen>\newsavebox{\quoteauthor}
 \newenvironment{citequote}[1][Shakespeare]{%
@@ -6380,32 +8238,31 @@
 
 <indexterm role="cp"><primary>theorem-like environment</primary></indexterm>
 <indexterm role="cp"><primary>environment, theorem-like</primary></indexterm>
-<para>Define a new theorem-like environment.  Synopses:
+<para>Synopses:
 </para>
 <screen>\newtheorem{<replaceable>name</replaceable>}{<replaceable>title</replaceable>}
 \newtheorem{<replaceable>name</replaceable>}{<replaceable>title</replaceable>}[<replaceable>numbered_within</replaceable>]
 \newtheorem{<replaceable>name</replaceable>}[<replaceable>numbered_like</replaceable>]{<replaceable>title</replaceable>}
 </screen>
-<para>Using the first form, <literal>\newtheorem{<replaceable>name</replaceable>}{<replaceable>title</replaceable>}</literal>
-creates an environment that will be labelled with <replaceable>title</replaceable>.  See the
-first example below.
+<para>Define a new theorem-like environment.  You can specify one of
+<replaceable>numbered_within</replaceable> and <replaceable>numbered_like</replaceable>, or neither, but not both.
 </para>
-<para>The second form
-<literal>\newtheorem{<replaceable>name</replaceable>}{<replaceable>title</replaceable>}[<replaceable>numbered_within</replaceable>]</literal>
+<para>The first form, <literal>\newtheorem{<replaceable>name</replaceable>}{<replaceable>title</replaceable>}</literal>, creates
+an environment that will be labelled with <replaceable>title</replaceable>; see the first
+example below.
+</para>
+<para>The second form,
+<literal>\newtheorem{<replaceable>name</replaceable>}{<replaceable>title</replaceable>}[<replaceable>numbered_within</replaceable>]</literal>,
 creates an environment whose counter is subordinate to the existing
-counter <replaceable>numbered_within</replaceable> (its counter will be reset when
-<replaceable>numbered_within</replaceable> is reset).
+counter <replaceable>numbered_within</replaceable>, so this counter will be reset when
+<replaceable>numbered_within</replaceable> is reset.  See the second example below.
 </para>
-
 <para>The third form
 <literal>\newtheorem{<replaceable>name</replaceable>}[<replaceable>numbered_like</replaceable>]{<replaceable>title</replaceable>}</literal>,
-with optional argument between the two required arguments, will create
-an environment whose counter will share the previously defined counter
-<replaceable>numbered_like</replaceable>.
+with optional argument between the two required arguments, creates an
+environment whose counter will share the previously defined counter
+<replaceable>numbered_like</replaceable>.  See the third example.
 </para>
-<para>You can specify one of <replaceable>numbered_within</replaceable> and <replaceable>numbered_like</replaceable>,
-or neither, but not both.
-</para>
 <para>This command creates a counter named <replaceable>name</replaceable>.  In addition, unless
 the optional argument <replaceable>numbered_like</replaceable> is used, inside of the
 theorem-like environment the current <literal>\ref</literal> value will be that of
@@ -6416,12 +8273,13 @@
 <para>Arguments:
 </para>
 <variablelist><varlistentry><term><replaceable>name</replaceable>
-</term><listitem><para>The name of the environment.  It must not begin with a backslash
-(‘<literal>\</literal>’).  It must not be the name of an existing environment; indeed,
-the command name <literal>\<replaceable>name</replaceable></literal> must not already be defined as anything.
+</term><listitem><para>The name of the environment.  It is a string of letters.  It must not
+begin with a backslash, <literal>\</literal>.  It must not be the name of an
+existing environment, and the command name <literal>\<replaceable>name</replaceable></literal> must not
+already be defined.
 </para>
 </listitem></varlistentry><varlistentry><term><replaceable>title</replaceable>
-</term><listitem><para>The text printed at the beginning of the environment, before the
+</term><listitem><para>The text to be printed at the beginning of the environment, before the
 number. For example, ‘<literal>Theorem</literal>’.
 </para>
 </listitem></varlistentry><varlistentry><term><replaceable>numbered_within</replaceable>
@@ -6455,10 +8313,10 @@
   Second def
 \end{defn}
 </screen>
-<para>Because the next example specifies the optional argument
-<replaceable>numbered_within</replaceable> to <literal>\newtheorem</literal> as <literal>section</literal>, the
-example, with the same document body, gives ‘<literal>Definition 1.1</literal>’
-and ‘<literal>Definition 2.1</literal>’.
+<para>This example has the same document body as the prior one.  But here
+<literal>\newtheorem</literal>’s optional argument <replaceable>numbered_within</replaceable> is given as
+<literal>section</literal>, so the output is like ‘<literal>Definition 1.1</literal>’ and
+‘<literal>Definition 2.1</literal>’.
 </para>
 <screen>\newtheorem{defn}{Definition}[section]
 \begin{document}
@@ -6497,43 +8355,41 @@
 
 </sect1>
 <sect1 label="12.8" id="_005cnewfont">
-<title><literal>\newfont</literal>: Define a new font (obsolete)</title>
+<title><literal>\newfont</literal></title>
 
 <indexterm role="fn"><primary>\newfont</primary></indexterm>
 <indexterm role="cp"><primary>fonts, new commands for</primary></indexterm>
 <indexterm role="cp"><primary>defining new fonts</primary></indexterm>
 
-<para><literal>\newfont</literal>, now obsolete, defines a command that will switch fonts.
-Synopsis:
+<!-- @findex .fd @r{file} -->
+<para>This command is obsolete. This description is here only to help with old
+documents.  New documents should define fonts in families through the
+New Font Selection Scheme which allows you to, for example, associate a
+boldface with a roman (see <link linkend="Fonts">Fonts</link>).
+<!-- This is done either by using -->
+<!-- @file{.fd} files or through the use of an engine that can access system -->
+<!-- fonts such as Xe at LaTeX{} (@pxref{@TeX{} engines}). -->
 </para>
+<para>Synopsis:
+</para>
 <screen>\newfont{\<replaceable>cmd</replaceable>}{<replaceable>font description</replaceable>}
 </screen>
-<para>This defines a control sequence <literal>\<replaceable>cmd</replaceable></literal> that will change the
-current font.  &latex; will look on your system for a file named
-<filename><replaceable>fontname</replaceable>.tfm</filename>.  The control sequence must must not already
-be defined.  It must begin with a backslash (‘<literal>\</literal>’).
+<para>Define a command <literal>\<replaceable>cmd</replaceable></literal> that will change the current font.
+The control sequence must must not already be defined.  It must begin
+with a backslash, <literal>\</literal>.
 </para>
-<indexterm role="fn"><primary>.fd file</primary></indexterm>
-<para>This command is obsolete.  It is a low-level command for setting up an
-individual font.  Today fonts are almost always defined in families
-(which allows you to, for example, associate a boldface with a roman)
-through the so-called “New Font Selection Scheme”, either by using
-<filename>.fd</filename> files or through the use of an engine that can access
-system fonts such as Xe&latex; (see <link linkend="TeX-engines">&tex; engines</link>).
-<!-- xx explain nfss somewhere -->
-</para>
 <indexterm role="cp"><primary>at clause, in font definitions</primary></indexterm>
 <indexterm role="cp"><primary>design size, in font definitions</primary></indexterm>
-<para>But since it is part of &latex;, here is an explanation: the
-<replaceable>font description</replaceable> consists of a <replaceable>fontname</replaceable> and an optional
-<firstterm>at clause</firstterm>; this can have the form either <literal>at <replaceable>dimen</replaceable></literal>
-or <literal>scaled <replaceable>factor</replaceable></literal>, where a <replaceable>factor</replaceable> of ‘<literal>1000</literal>’
-means no scaling.  For &latex;’s purposes, all this does is scale all
-the character and other font dimensions relative to the font’s design
-size, which is a value defined in the <filename>.tfm</filename> file.
+<para>The <replaceable>font description</replaceable> consists of a <replaceable>fontname</replaceable> and an optional
+<firstterm>at clause</firstterm>.  &latex; will look on your system for a file named
+<filename><replaceable>fontname</replaceable>.tfm</filename>.  The at clause can have the form either
+<literal>at <replaceable>dimen</replaceable></literal> or <literal>scaled <replaceable>factor</replaceable></literal>, where a
+<replaceable>factor</replaceable> of ‘<literal>1000</literal>’ means no scaling.  For &latex;’s purposes,
+all this does is scale all the character and other font dimensions
+relative to the font’s design size, which is a value defined in the
+<filename>.tfm</filename> file.
 </para>
-<para>This example defines two equivalent fonts and typesets a few
-characters in each:
+<para>This defines two equivalent fonts and typesets a few characters in each.
 </para>
 <screen>\newfont{\testfontat}{cmb10 at 11pt}
 \newfont{\testfontscaled}{cmb10 scaled 1100}
@@ -6634,12 +8490,14 @@
 <screen>\newcommand{\points}[1]{\makebox[0pt]{\makebox[10em][l]{#1~pts}}
 \begin{enumerate} 
   \item\points{10}no extra space output here
-  \item\points{15} extra space output between the number and the word `extra'
+  \item\points{15} extra space between the number and the `extra'
 \end{enumerate} 
 </screen>
-<para>The solution is to change to
-<literal>\newcommand{\points}[1]{\makebox[0pt]{\makebox[10em][l]{#1~pts}}\ignorespaces}</literal>.
+<para>The solution is to change to this.
 </para>
+<screen>\newcommand{\points}[1]{%
+  \makebox[0pt]{\makebox[10em][l]{#1~pts}}\ignorespaces}
+</screen>
 <para>A second example shows spaces being removed from the front of text.  The
 commands below allow a user to uniformly attach a title to names.  But,
 as given, if a title accidentally starts with a space then
@@ -6647,7 +8505,7 @@
 </para>
 <screen>\makeatletter
 \newcommand{\honorific}[1]{\def\@honorific{#1}} % remember title
-\newcommand{\fullname}[1]{\@honorific~#1}       % recall title; put before name
+\newcommand{\fullname}[1]{\@honorific~#1}       % put title before name
 \makeatother
 \begin{tabular}{|l|}
 \honorific{Mr/Ms}  \fullname{Jones} \\  % no extra space here
@@ -6713,6 +8571,8 @@
 through <literal>enumiv</literal> are used in the <literal>enumerate</literal> environment, for
 up to four levels of nesting (see <link linkend="enumerate">enumerate</link>).
 </para>
+<para>Counters can have any integer value but they are typically positive.
+</para>
 <para>New counters are created with <literal>\newcounter</literal>.  See <link linkend="_005cnewcounter">\newcounter</link>.
 </para>
 
@@ -6725,7 +8585,7 @@
 
 <para>Print the value of a counter, in a specified style.  For instance, if
 the counter <replaceable>counter</replaceable> has the value 1 then a
-<literal>\alph{<replaceable>counter</replaceable>}</literal> in your source will result in a lower case
+<literal>\alph{<replaceable>counter</replaceable>}</literal> in your source will result in a lowercase
 letter a appearing in the output.
 </para>
 <para>All of these commands take a single counter as an argument, for
@@ -6733,46 +8593,54 @@
 start with a backslash.
 </para>
 <variablelist><varlistentry><term><indexterm role="fn"><primary>\alph{<replaceable>counter</replaceable>}</primary></indexterm><literal>\alph{<replaceable>counter</replaceable>}</literal>
-</term><listitem><para>Print the value of <replaceable>counter</replaceable> in lowercase letters: ‘a’, ‘b’, ...
+</term><listitem><para>Print the value of <replaceable>counter</replaceable> in lowercase letters: ‘a’, ‘b’,
+... If the counter’s value is less than 1 or more than 26 then
+you get ‘<literal>LaTeX Error: Counter too large.</literal>’
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\Alph{<replaceable>counter</replaceable>}</primary></indexterm><literal>\Alph{<replaceable>counter</replaceable>}</literal>
-</term><listitem><para>Print in uppercase letters: ‘A’, ‘B’, ...
+</term><listitem><para>Print in uppercase letters: ‘A’, ‘B’, ... If the counter’s value
+is less than 1 or more than 26 then you get ‘<literal>LaTeX Error: Counter
+too large.</literal>’
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\arabic{<replaceable>counter</replaceable>}</primary></indexterm><literal>\arabic{<replaceable>counter</replaceable>}</literal>
-</term><listitem><para>Print in Arabic numbers: ‘1’, ‘2’, ...
+</term><listitem><para>Print in Arabic numbers such as ‘<literal>5</literal>’ or ‘<literal>-2</literal>’.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\roman{<replaceable>counter</replaceable>}</primary></indexterm><literal>\roman{<replaceable>counter</replaceable>}</literal>
-</term><listitem><para>Print in lowercase roman numerals: ‘i’, ‘ii’, ...
+</term><listitem><para>Print in lowercase roman numerals: ‘i’, ‘ii’, ... If the
+counter’s value is less than 1 then you get no warning or error but
+&latex; does not print anything in the output.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\Roman{<replaceable>counter</replaceable>}</primary></indexterm><literal>\Roman{<replaceable>counter</replaceable>}</literal>
-</term><listitem><para>Print in uppercase roman numerals: ‘I’, ‘II’, ...
+</term><listitem><para>Print in uppercase roman numerals: ‘I’, ‘II’, ... If the
+counter’s value is less than 1 then you get no warning or error but
+&latex; does not print anything in the output.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\fnsymbol{<replaceable>counter</replaceable>}</primary></indexterm><literal>\fnsymbol{<replaceable>counter</replaceable>}</literal>
-</term><listitem><para>Prints the value of <replaceable>counter</replaceable> in a specific sequence of nine
-symbols (conventionally used for labeling footnotes).  The value of
-<replaceable>counter</replaceable> must be between 1 and 9, inclusive.
+</term><listitem><para>Prints the value of <replaceable>counter</replaceable> using a sequence of nine symbols that
+are traditionally used for labeling footnotes.  The value of
+<replaceable>counter</replaceable> should be between 1 and 9, inclusive.  If the
+counter’s value is less than 0 or more than 9 then you get ‘<literal>LaTeX
+Error: Counter too large</literal>’, while if it is 0 then you get no error or
+warning but &latex; does not output anything.
 </para>
 <para>Here are the symbols:
 </para>
-<informaltable><tgroup cols="3"><colspec colwidth="33*"></colspec><colspec colwidth="33*"></colspec><colspec colwidth="33*"></colspec><thead><row><entry><para>Name</para></entry><entry><para>Command</para></entry><entry><para>Equivalent Unicode symbol and/or numeric code point<!--
- -->
-</para></entry></row></thead><tbody><row><entry><para>asterisk</para></entry><entry><para><literal>\ast</literal></para></entry><entry><para>*<!--
- -->
-</para></entry></row><row><entry><para>dagger</para></entry><entry><para><literal>\dagger</literal></para></entry><entry><para>&#x2020;
-</para></entry></row><row><entry><para>ddagger</para></entry><entry><para><literal>\ddagger</literal></para></entry><entry><para>&#x2021;
-</para></entry></row><row><entry><para>section-sign</para></entry><entry><para><literal>\S</literal></para></entry><entry><para>&#x00A7;
-</para></entry></row><row><entry><para>paragraph-sign</para></entry><entry><para><literal>\P</literal></para></entry><entry><para>&#x00B6;
-</para></entry></row><row><entry><para>double-vert</para></entry><entry><para><literal>\parallel</literal></para></entry><entry><para>&#x2016;
-</para></entry></row><row><entry><para>double-asterisk</para></entry><entry><para><literal>\ast\ast</literal></para></entry><entry><para>**<!--
- -->
-</para></entry></row><row><entry><para>double-dagger</para></entry><entry><para><literal>\dagger\dagger</literal></para></entry><entry><para>&#x2020;&#x2020;
-</para></entry></row><row><entry><para>double-ddagger</para></entry><entry><para><literal>\ddagger\ddagger</literal></para></entry><entry><para>&#x2021;&#x2021;
+<informaltable><tgroup cols="4"><colspec colwidth="10*"></colspec><colspec colwidth="30*"></colspec><colspec colwidth="30*"></colspec><colspec colwidth="30*"></colspec><thead><row><entry><para>Number</para></entry><entry><para>Name</para></entry><entry><para>Command</para></entry><entry><para>Symbol
+</para></entry></row></thead><tbody><row><entry><para>1</para></entry><entry><para>asterisk</para></entry><entry><para><literal>\ast</literal></para></entry><entry><para>*<!-- -->
+</para></entry></row><row><entry><para>2</para></entry><entry><para>dagger</para></entry><entry><para><literal>\dagger</literal></para></entry><entry><para>&#x2020;
+</para></entry></row><row><entry><para>3</para></entry><entry><para>ddagger</para></entry><entry><para><literal>\ddagger</literal></para></entry><entry><para>&#x2021;
+</para></entry></row><row><entry><para>4</para></entry><entry><para>section-sign</para></entry><entry><para><literal>\S</literal></para></entry><entry><para>&#x00A7;
+</para></entry></row><row><entry><para>5</para></entry><entry><para>paragraph-sign</para></entry><entry><para><literal>\P</literal></para></entry><entry><para>&#x00B6;
+</para></entry></row><row><entry><para>6</para></entry><entry><para>double-vert</para></entry><entry><para><literal>\parallel</literal></para></entry><entry><para>&#x2016;
+</para></entry></row><row><entry><para>7</para></entry><entry><para>double-asterisk</para></entry><entry><para><literal>\ast\ast</literal></para></entry><entry><para>**<!-- -->
+</para></entry></row><row><entry><para>8</para></entry><entry><para>double-dagger</para></entry><entry><para><literal>\dagger\dagger</literal></para></entry><entry><para>&#x2020;&#x2020;
+</para></entry></row><row><entry><para>9</para></entry><entry><para>double-ddagger</para></entry><entry><para><literal>\ddagger\ddagger</literal></para></entry><entry><para>&#x2021;&#x2021;
 </para></entry></row></tbody></tgroup></informaltable>
 </listitem></varlistentry></variablelist>
 
 </sect1>
 <sect1 label="13.2" id="_005cusecounter">
-<title><literal>\usecounter{<replaceable>counter</replaceable>}</literal></title>
+<title><literal>\usecounter</literal></title>
 
 <indexterm role="fn"><primary>\usecounter</primary></indexterm>
 <indexterm role="cp"><primary>list items, specifying counter</primary></indexterm>
@@ -6782,15 +8650,16 @@
 </para>
 <screen>\usecounter{<replaceable>counter</replaceable>}
 </screen>
-<para>In the <literal>list</literal> environment, when used in the second argument, this
-command sets up <replaceable>counter</replaceable> to number the list items.  It initializes
-<replaceable>counter</replaceable> to zero, and arranges that when <literal>\item</literal> is called
-without its optional argument then <replaceable>counter</replaceable> is incremented by
-<literal>\refstepcounter</literal>, making its value be the current <literal>ref</literal>
-value.  This command is fragile (see <link linkend="_005cprotect">\protect</link>).
+<para>Used in the second argument of the <literal>list</literal> environment
+(see <link linkend="list">list</link>), this declares that list items will be numbered by
+<replaceable>counter</replaceable>.  It initializes <replaceable>counter</replaceable> to zero, and arranges that
+when <literal>\item</literal> is called without its optional argument then
+<replaceable>counter</replaceable> is incremented by <literal>\refstepcounter</literal>, making its value
+be the current <literal>ref</literal> value (see <link linkend="_005cref">\ref</link>).  This command is fragile
+(see <link linkend="_005cprotect">\protect</link>).
 </para>
-<para>Put in the preamble, this makes a new list environment enumerated with
-<replaceable>testcounter</replaceable>:
+<para>Put in the document preamble, this example makes a new list environment
+enumerated with <replaceable>testcounter</replaceable>:
 </para>
 <screen>\newcounter{testcounter}
 \newenvironment{test}{%
@@ -6804,7 +8673,7 @@
 
 </sect1>
 <sect1 label="13.3" id="_005cvalue">
-<title><literal>\value{<replaceable>counter</replaceable>}</literal></title>
+<title><literal>\value</literal></title>
 
 <indexterm role="fn"><primary>\value</primary></indexterm>
 <indexterm role="cp"><primary>counters, getting value of</primary></indexterm>
@@ -6813,14 +8682,9 @@
 </para>
 <screen>\value{<replaceable>counter</replaceable>}
 </screen>
-<para>This command expands to the value of <replaceable>counter</replaceable>.  It is often used
-in <literal>\setcounter</literal> or <literal>\addtocounter</literal>, but <literal>\value</literal> can
-be used anywhere that &latex; expects a number.  It must not be
-preceded by <literal>\protect</literal> (see <link linkend="_005cprotect">\protect</link>).
+<para>Expands to the value of the counter <replaceable>counter</replaceable>. (Note that the name
+of a counter does not begin with a backslash.)
 </para>
-<para>The <literal>\value</literal> command is not used for typesetting the value of the
-counter.  See <link linkend="_005calph-_005cAlph-_005carabic-_005croman-_005cRoman-_005cfnsymbol">\alph \Alph \arabic \roman \Roman \fnsymbol</link>.
-</para>
 <para>This example outputs ‘<literal>Test counter is 6. Other counter
 is 5.</literal>’.
 </para>
@@ -6831,6 +8695,14 @@
 Test counter is \arabic{test}.
 Other counter is \arabic{other}.
 </screen>
+<para>The <literal>\value</literal> command is not used for typesetting the value of the
+counter.  For that, see <link linkend="_005calph-_005cAlph-_005carabic-_005croman-_005cRoman-_005cfnsymbol">\alph \Alph \arabic \roman \Roman \fnsymbol</link>.
+</para>
+<para>It is often used in <literal>\setcounter</literal> or <literal>\addtocounter</literal> but
+<literal>\value</literal> can be used anywhere that &latex; expects a number, such
+as in <literal>\hspace{\value{foo}\parindent}</literal>.  It must not be
+preceded by <literal>\protect</literal> (see <link linkend="_005cprotect">\protect</link>).
+</para>
 <para>This example inserts <literal>\hspace{4\parindent}</literal>.
 </para>
 <screen>\setcounter{myctr}{3} \addtocounter{myctr}{1}
@@ -6839,7 +8711,7 @@
 
 </sect1>
 <sect1 label="13.4" id="_005csetcounter">
-<title><literal>\setcounter{<replaceable>counter</replaceable>}{<replaceable>value</replaceable>}</literal></title>
+<title><literal>\setcounter</literal></title>
 
 <indexterm role="fn"><primary>\setcounter</primary></indexterm>
 <indexterm role="cp"><primary>counters, setting</primary></indexterm>
@@ -6849,25 +8721,30 @@
 </para>
 <screen>\setcounter{<replaceable>counter</replaceable>}{<replaceable>value</replaceable>}
 </screen>
-<para>The <literal>\setcounter</literal> command globally sets the value of <replaceable>counter</replaceable>
-to the <replaceable>value</replaceable> argument.  Note that the counter name does not start
-with a backslash.
+<para>Globally set the counter <replaceable>counter</replaceable> to have the value of the
+<replaceable>value</replaceable> argument, which must be an integer.  Thus, you can set a
+counter’s value as <literal>\setcounter{section}{5}</literal>.  Note that the
+counter name does not start with a backslash.
 </para>
-<para>In this example the section value appears as ‘<literal>V</literal>’.
+<para>In this example if the counter <literal>theorem</literal> has value 12 then the
+second line will print ‘<literal>XII</literal>’.
 </para>
-<screen>\setcounter{section}{5}
-Here it is in Roman: \Roman{section}.
+<screen>\setcounter{exercise}{\value{theorem}}
+Here it is in Roman: \Roman{exercise}.
 </screen>
 
 </sect1>
 <sect1 label="13.5" id="_005caddtocounter">
-<title><literal>\addtocounter{<replaceable>counter</replaceable>}{<replaceable>value</replaceable>}</literal></title>
+<title><literal>\addtocounter</literal></title>
 
 <indexterm role="fn"><primary>\addtocounter</primary></indexterm>
 
-<para>The <literal>\addtocounter</literal> command globally increments <replaceable>counter</replaceable> by
-the amount specified by the <replaceable>value</replaceable> argument, which may be negative.
+<para>Synopsis:
 </para>
+<screen>\addtocounter{<replaceable>counter</replaceable>}{<replaceable>value</replaceable> </screen>
+<para>Globally increment <replaceable>counter</replaceable> by the amount specified by the
+<replaceable>value</replaceable> argument, which may be negative.
+</para>
 <para>In this example the section value appears as ‘<literal>VII</literal>’.
 </para>
 <screen>\setcounter{section}{5}
@@ -6877,16 +8754,19 @@
 
 </sect1>
 <sect1 label="13.6" id="_005crefstepcounter">
-<title><literal>\refstepcounter{<replaceable>counter</replaceable>}</literal></title>
+<title><literal>\refstepcounter</literal></title>
 
 <indexterm role="fn"><primary>\refstepcounter</primary></indexterm>
 
-<para>The <literal>\refstepcounter</literal> command works in the same way as
-<literal>\stepcounter</literal> (see <link linkend="_005cstepcounter">\stepcounter</link>): it globally increments the
-value of <replaceable>counter</replaceable> by one and resets the value of any counter
-numbered within it.  (For the definition of “counters numbered
-within”, see <link linkend="_005cnewcounter">\newcounter</link>.)
+<para>Synopsis:
 </para>
+<screen>\refstepcounter{<replaceable>counter</replaceable>}
+</screen>
+<para>Globally increments the value of <replaceable>counter</replaceable> by one, as does
+<literal>\stepcounter</literal> (see <link linkend="_005cstepcounter">\stepcounter</link>).  The difference is that this
+command resets the value of any counter numbered within it.  (For the
+definition of “counters numbered within”, see <link linkend="_005cnewcounter">\newcounter</link>.)
+</para>
 <para>In addition, this command also defines the current <literal>\ref</literal> value
 to be the result of <literal>\thecounter</literal>.
 </para>
@@ -6896,32 +8776,48 @@
 
 </sect1>
 <sect1 label="13.7" id="_005cstepcounter">
-<title><literal>\stepcounter{<replaceable>counter</replaceable>}</literal></title>
+<title><literal>\stepcounter</literal></title>
 
 <indexterm role="fn"><primary>\stepcounter</primary></indexterm>
 
-<para>The <literal>\stepcounter</literal> command globally adds one to <replaceable>counter</replaceable> and
-resets all counters numbered within it.  (For the definition of
-“counters numbered within”, see <link linkend="_005cnewcounter">\newcounter</link>.)
+<para>Synopsis:
 </para>
+<screen>\stepcounter{<replaceable>counter</replaceable>}
+</screen>
+<para>Globally adds one to <replaceable>counter</replaceable> and resets all counters numbered
+within it.  (For the definition of “counters numbered within”,
+see <link linkend="_005cnewcounter">\newcounter</link>.)
+</para>
+<para>This command differs from <literal>\refstepcounter</literal> in that this one does
+not influence references — it does not define the current
+<literal>\ref</literal> value to be the result of <literal>\thecounter</literal>
+(see <link linkend="_005crefstepcounter">\refstepcounter</link>).
+</para>
 
 </sect1>
-<sect1 label="13.8" id="_005cday-_005cmonth-_005cyear">
-<title><literal>\day \month \year</literal>: Predefined counters</title>
+<sect1 label="13.8" id="_005cday-_0026-_005cmonth-_0026-_005cyear">
+<title><literal>\day</literal> & <literal>\month</literal> & <literal>\year</literal></title>
 
 <indexterm role="fn"><primary>\day</primary></indexterm>
 <indexterm role="fn"><primary>\month</primary></indexterm>
 <indexterm role="fn"><primary>\year</primary></indexterm>
 
-<para>&latex; defines counters for the day of the month (<literal>\day</literal>,
-1–31), month of the year (<literal>\month</literal>, 1–12), and year
-(<literal>\year</literal>, Common Era).  When &tex; starts up, they are
-set to the current values on the system where &tex; is running.  They
-are not updated as the job progresses.
+<para>&latex; defines the counter <literal>\day</literal> for the day of the month
+(nominally with value between 1 and 31), <literal>\month</literal> for the month of
+the year (nominally with value between 1 and 12), and year <literal>\year</literal>.
+When &tex; starts up, they are set from the current values on the
+system.  The related command <literal>\today</literal> produces a string
+representing the current day (see <link linkend="_005ctoday">\today</link>).
 </para>
-<para>The related command <literal>\today</literal> produces a string representing the
-current day (see <link linkend="_005ctoday">\today</link>).
+<para>They counters are not updated as the job progresses so in principle they
+could be incorrect by the end.  In addition, &tex; does no sanity
+check:
 </para>
+<screen>\day=-2 \month=13 \year=-4 \today
+</screen>
+<para>gives no error or warning and results in the output ‘<literal>-2, -4</literal>’ (the
+bogus month value produces no output).
+</para>
 
 </sect1>
 </chapter>
@@ -6933,32 +8829,99 @@
 <para>A <firstterm>length</firstterm> is a measure of distance.  Many &latex; commands take a
 length as an argument.
 </para>
+<para>This shows a box of the given length.
+</para>
+<screen>\newcommand{\blackbar}[1]{\rule{#1}{10pt}}   % make a bar 
+\newcommand{\showhbox}[2]{\fboxsep=0pt\fbox{\hbox to #1{#2}}} % box it
+XXX\showhbox{100pt}{\blackbar{100pt}}YYY
+</screen>
+<para>It produces a black bar 100 points long between ‘<literal>XXX</literal>’ and
+‘<literal>YYY</literal>’.
+</para>
 <para>Lengths come in two types.  A <firstterm>rigid length</firstterm> (what Plain &tex;
-calls a <firstterm>dimen</firstterm>) such as <literal>10pt</literal> cannot contain a <literal>plus</literal> or
-<literal>minus</literal> component.  A <firstterm>rubber length</firstterm> (what Plain &tex; calls
-a <firstterm>skip</firstterm>) can contain those, as with <literal>1cm plus0.05cm
-minus0.01cm</literal>.  These give the ability to stretch or shrink; the length
-in the prior sentence could appear in the output as long as 1.05 cm
-or as short as 0.99 cm, depending on what &tex;’s typesetting
-algorithm finds optimum.
+calls a <firstterm>dimen</firstterm>) such as <literal>10pt</literal> does not contain a <literal>plus</literal>
+or <literal>minus</literal> component.  The above example shows a rigid length. A
+<firstterm>rubber length</firstterm> (what Plain &tex; calls a <firstterm>skip</firstterm>) can contain
+those components, as with <literal>1cm plus0.05cm minus0.01cm</literal>.  Here the
+<literal>1cm</literal> is the <firstterm>natural length</firstterm> while the other two, the
+<literal>plus</literal> and <literal>minus</literal> components, allow the length to stretch or
+shrink.
 </para>
+<para>Shrinking is simpler: with <literal>1cm minus 0.05cm</literal>, the natural length
+is 1cm but if smaller is needed then &tex; can shrink it down as
+far as 0.95cm.  Beyond that, &tex; refuses to shrink any more.
+Thus, below the first one works fine, producing a space of
+98 points between the two bars.
+</para>
+<screen>XXX\showhbox{300pt}{%
+  \blackbar{101pt}\hspace{100pt minus 2pt}\blackbar{101pt}}YYY
+
+XXX\showhbox{300pt}{%
+  \blackbar{105pt}\hspace{100pt minus 1pt}\blackbar{105pt}}YYY
+</screen>
+<para>But the second one gets a warning like ‘<literal>Overfull \hbox (1.0pt too
+wide) detected at line 17</literal>’.  In the output the first ‘<literal>Y</literal>’ is
+overwritten by the end of the black bar, because the box’s material is
+wider than the 300pt allocated, as &tex; has refused to shrink
+the total to less than 309 points.
+</para>
+<para>Stretching is like shrinking except that if &tex; is asked to stretch
+beyond the given amount, it won’t refuse.  Here the first line is fine,
+producing a space of 110 points between the bars.
+</para>
+<screen>XXX\showhbox{300pt}{%
+  \blackbar{95pt}\hspace{100pt plus 10pt}\blackbar{95pt}}YYY
+
+XXX\showhbox{300pt}{%
+  \blackbar{95pt}\hspace{100pt plus 1pt}\blackbar{95pt}}YYY
+</screen>
+<para>In the second line &tex; needs a stretch of 10 points and only
+1 point was specified.  In this situation, &tex; stretches the
+space to the required length, but it complains with a warning like
+‘<literal>Underfull \hbox (badness 10000) detected at line 22</literal>’.  (We won’t
+discuss badness; the point is that the system was not given as much
+stretch as needed.)
+</para>
+<para>You can put both stretch and shrink in the same length, as in
+<literal>1ex plus 0.05ex minus 0.02ex</literal>.
+</para>
+<para>If &tex; is setting two or more rubber lengths then it allocates the
+stretch or shrink in proportion.
+</para>
+<screen>XXX\showhbox{300pt}{\blackbar{100pt}%  left
+  \hspace{0pt plus 50pt}\blackbar{80pt}\hspace{0pt plus 10pt}%  middle
+  \blackbar{100pt}}YYY  % right
+</screen>
+<para>The outside bars take up 100 points, so the middle needs another
+100.  In the middle the bar takes up 80 points, so the two
+<literal>\hspace</literal>’s must stretch 20 points.  Because the two say
+<literal>plus 50pt</literal> and <literal>plus 10pt</literal>, &tex; gets 5/6 of the
+stretch from the first space and 1/6 from the second.
+</para>
 <para>The <literal>plus</literal> or <literal>minus</literal> component of a rubber length can contain
 a <firstterm>fill</firstterm> component, as in <literal>1in plus2fill</literal>.  This gives the
-length infinite stretchability or shrinkability, so that the length in
-the prior sentence can be set by &tex; to any distance greater than or
-equal to 1 inch.  &tex; actually provides three infinite glue
-components <literal>fil</literal>, <literal>fill</literal>, and <literal>filll</literal>, such that the
-later ones overcome the earlier ones, but only the middle value is
-ordinarily used.  See <link linkend="_005chfill">\hfill</link>, See <link linkend="_005cvfill">\vfill</link>.
+length infinite stretchability or shrinkability so that &tex; could set
+it to any distance.  Here the two figures will be equal-spaced across
+the page.
 </para>
-<para>Multiplying an entire rubber length by a number turns it into a rigid
-length, so that after <literal>\setlength{\ylength}{1in plus 0.2in}</literal>
-and <literal>\setlength{\zlength}{3\ylength}</literal> then the value of
+<screen>\begin{minipage}{\linewidth}
+  \hspace{0pt plus 1fill}\includegraphics{godel.png}%
+  \hspace{0pt plus 1fill}\includegraphics{einstein.png}%
+  \hspace{0pt plus 1fill}
+\end{minipage}
+</screen>
+<para>&tex; actually has three infinite glue components <literal>fil</literal>,
+<literal>fill</literal>, and <literal>filll</literal>.  The later ones are more infinite than
+the earlier ones.  Ordinarily document authors only use the middle one
+(see <link linkend="_005chfill">\hfill</link> and see <link linkend="_005cvfill">\vfill</link>).
+</para>
+<para>Multiplying a rubber length by a number turns it into a rigid length, so
+that after <literal>\setlength{\ylength}{1in plus 0.2in}</literal> and
+<literal>\setlength{\zlength}{3\ylength}</literal> then the value of
 <literal>\zlength</literal> is <literal>3in</literal>.
 </para>
 
 
-
 <sect1 label="14.1" id="Units-of-length">
 <title>Units of length</title>
 
@@ -6970,49 +8933,49 @@
 <variablelist><varlistentry><term><literal>pt</literal>
 </term><listitem><indexterm role="fn"><primary>pt</primary></indexterm>
 <indexterm role="cp"><primary>Point</primary></indexterm>
-<para>Point 1/72.27 inch.  The conversion to metric units, to two decimal
+<anchor id="units-of-length-pt"/><para>Point 1/72.27 inch.  The conversion to metric units, to two decimal
 places, is 1point = 2.85mm = 28.45cm. 
 </para>
 </listitem></varlistentry><varlistentry><term><literal>pc</literal>
 </term><listitem><indexterm role="cp"><primary>pica</primary></indexterm>
 <indexterm role="fn"><primary>pc</primary></indexterm>
-<para>Pica, 12 pt
+<anchor id="units-of-length-pc"/><para>Pica, 12 pt
 </para>
 </listitem></varlistentry><varlistentry><term><literal>in</literal>
 </term><listitem><indexterm role="fn"><primary>in</primary></indexterm>
 <indexterm role="fn"><primary>inch</primary></indexterm>
-<para>Inch,  72.27 pt
+<anchor id="units-of-length-in"/><para>Inch,  72.27 pt
 </para>
 </listitem></varlistentry><varlistentry><term><literal>bp</literal>
 </term><listitem><indexterm role="fn"><primary>bp</primary></indexterm>
 <indexterm role="cp"><primary>Big point</primary></indexterm>
-<para>Big point, 1/72 inch.  This length is the definition of a point in
+<anchor id="units-of-length-bp"/><para>Big point, 1/72 inch.  This length is the definition of a point in
 PostScript and many desktop publishing systems.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>cm</literal>
 </term><listitem><indexterm role="cp"><primary>Centimeter</primary></indexterm>
 <indexterm role="fn"><primary>cm</primary></indexterm>
-<para>Centimeter
+<anchor id="units-of-length-cm"/><para>Centimeter
 </para>
 </listitem></varlistentry><varlistentry><term><literal>mm</literal>
 </term><listitem><indexterm role="cp"><primary>Millimeter</primary></indexterm>
 <indexterm role="fn"><primary>mm</primary></indexterm>
-<para>Millimeter
+<anchor id="units-of-length-mm"/><para>Millimeter
 </para>
 </listitem></varlistentry><varlistentry><term><literal>dd</literal>
 </term><listitem><indexterm role="cp"><primary>Didot point</primary></indexterm>
 <indexterm role="fn"><primary>dd</primary></indexterm>
-<para>Didot point, 1.07 pt
+<anchor id="units-of-length-dd"/><para>Didot point, 1.07 pt
 </para>
 </listitem></varlistentry><varlistentry><term><literal>cc</literal>
 </term><listitem><indexterm role="cp"><primary>Cicero</primary></indexterm>
 <indexterm role="fn"><primary>cc</primary></indexterm>
-<para>Cicero, 12 dd
+<anchor id="units-of-length-cc"/><para>Cicero, 12 dd
 </para>
 </listitem></varlistentry><varlistentry><term><literal>sp</literal>
 </term><listitem><indexterm role="cp"><primary>Scaled point</primary></indexterm>
 <indexterm role="fn"><primary>sp</primary></indexterm>
-<para>Scaled point, 1/65536 pt
+<anchor id="units-of-length-sp"/><para>Scaled point, 1/65536 pt
 </para>
 </listitem></varlistentry></variablelist>
 <indexterm role="cp"><primary>ex</primary></indexterm>
@@ -7021,9 +8984,9 @@
 <indexterm role="cp"><primary>m-width</primary></indexterm>
 <indexterm role="cp"><primary>em</primary></indexterm>
 <indexterm role="fn"><primary>em</primary></indexterm>
-<para>Two other lengths that are often used are values set by the designer of
+<anchor id="Lengths_002fem"/><anchor id="Lengths_002fen"/><anchor id="Lengths_002fex"/><anchor id="units-of-length-em"/><anchor id="units-of-length-en"/><anchor id="units-of-length-ex"/><para>Two other lengths that are often used are values set by the designer of
 the font.  The x-height of the current font <firstterm>ex</firstterm>, traditionally the
-height of the lower case letter x, is often used for vertical
+height of the lowercase letter x, is often used for vertical
 lengths. Similarly <firstterm>em</firstterm>, traditionally the width of the capital
 letter M, is often used for horizontal lengths (there is also
 <literal>\enspace</literal>, which is <literal>0.5em</literal>).  Use of these can help make a
@@ -7049,15 +9012,26 @@
 
 <para>Synopsis:
 </para>
-<screen>\setlength{<replaceable>\len</replaceable>}{<replaceable>amount</replaceable>}
+<screen>\setlength{<replaceable>len</replaceable>}{<replaceable>amount</replaceable>}
 </screen>
-<para>The <literal>\setlength</literal> sets the value of <firstterm>length command</firstterm>
-<indexterm role="cp"><primary>length command</primary></indexterm>
-<literal>\<replaceable>len</replaceable></literal> to the <replaceable>value</replaceable> argument which can be expressed in any
-units that &latex; understands, i.e., inches (<literal>in</literal>), millimeters
-(<literal>mm</literal>), points (<literal>pt</literal>), big points (<literal>bp</literal>), etc.
+<para>Set the length <replaceable>len</replaceable> to <replaceable>amount</replaceable>.  The length name <replaceable>len</replaceable>
+must begin with a backslash, <literal>\</literal>.  The <literal>amount</literal> can be a
+rubber length (see <link linkend="Lengths">Lengths</link>).  It can be positive, negative or zero,
+and can be in any units that &latex; understands (see <link linkend="Units-of-length">Units of
+length</link>).
 </para>
+<para>Below, with &latex;’s defaults the first paragraph will be indented
+while the second will not.
+</para>
+<screen>I told the doctor I broke my leg in two places.
 
+\setlength{\parindent}{0em}
+He said stop going to those places.
+</screen>
+<para>If there is no such length <replaceable>len</replaceable> then you get something like
+‘<literal>Undefined control sequence. <argument> \praindent</literal>’.
+</para>
+
 </sect1>
 <sect1 label="14.3" id="_005caddtolength">
 <title><literal>\addtolength</literal></title>
@@ -7067,13 +9041,29 @@
 
 <para>Synopsis:
 </para>
-<screen>\addtolength{<replaceable>\len</replaceable>}{<replaceable>amount</replaceable>}
+<screen>\addtolength{<replaceable>len</replaceable>}{<replaceable>amount</replaceable>}
 </screen>
+<para>Increment the length <replaceable>len</replaceable> by <replaceable>amount</replaceable>.  The length name
+<replaceable>len</replaceable> begins with a backslash, <literal>\</literal>.  The <literal>amount</literal> is a
+rubber length (see <link linkend="Lengths">Lengths</link>).  It can be positive, negative or zero,
+and can be in any units that &latex; understands (see <link linkend="Units-of-length">Units of
+length</link>).
+</para>
+<para>Below, if <literal>\parskip</literal> starts with the value <literal>0pt plus 1pt</literal> 
+</para>
+<screen>\addtolength{\parskip}{1pt}
+Doctor: how is the boy who swallowed the silver dollar?
 
-<para>The <literal>\addtolength</literal> command increments a length command <literal>\<replaceable>len</replaceable></literal>
-by the amount specified in the <replaceable>amount</replaceable> argument, which may be
-negative.
+Nurse: no change.
+</screen>
+<para>then it has the value <literal>1pt plus 1pt</literal> for the second paragraph.
 </para>
+<para>If there is no such length <replaceable>len</replaceable> then you get something like
+‘<literal>Undefined control sequence. <argument> \praindent</literal>’.  If you leave
+off the backslash at the start of <replaceable>len</replaceable>, as in
+<literal>\addtolength{parindent}{1pt}</literal>, then you get something like
+‘<literal>You can't use `the letter p' after \advance</literal>’.
+</para>
 
 </sect1>
 <sect1 label="14.4" id="_005csettodepth">
@@ -7083,11 +9073,24 @@
 
 <para>Synopsis:
 </para>
-<screen>\settodepth{\<replaceable>len</replaceable>}{<replaceable>text</replaceable>}
+<screen>\settodepth{<replaceable>len</replaceable>}{<replaceable>text</replaceable>}
 </screen>
-<para>The <literal>\settodepth</literal> command sets the value of a length command
-<literal>\<replaceable>len</replaceable></literal> equal to the depth of the <replaceable>text</replaceable> argument.
+<para>Set the length <replaceable>len</replaceable> to the depth of box that &latex; gets on
+typesetting the <replaceable>text</replaceable> argument.  The length name <replaceable>len</replaceable> must
+begin with a backslash, <literal>\</literal>.
 </para>
+<para>This will show how low the character descenders go.
+</para>
+<screen>\newlength{\alphabetdepth}
+\settodepth{\alphabetdepth}{abcdefghijklmnopqrstuvwxyz}
+\the\alphabetdepth
+</screen>
+<para>If there is no such length <replaceable>len</replaceable> then you get something like
+‘<literal>Undefined control sequence. <argument> \alphabetdepth</literal>’.  If you
+leave the backslash out of <replaceable>len</replaceable>, as in
+<literal>\settodepth{alphabetdepth}{...}</literal> then you get something like
+‘<literal>Missing number, treated as zero. <to be read again> \setbox</literal>’.
+</para>
 
 </sect1>
 <sect1 label="14.5" id="_005csettoheight">
@@ -7097,55 +9100,81 @@
 
 <para>Synopsis:
 </para>
-<screen>\settoheight{\<replaceable>len</replaceable>}{text}
+<screen>\settoheight{<replaceable>len</replaceable>}{text}
 </screen>
-<para>The <literal>\settoheight</literal> command sets the value of a length command <literal>\<replaceable>len</replaceable></literal>
-equal to the height of the <literal>text</literal> argument.
+<para>Sets the length <replaceable>len</replaceable> to the height of box that &latex; gets on
+typesetting the <literal>text</literal> argument.  The length name <replaceable>len</replaceable> must
+begin with a backslash, <literal>\</literal>.
 </para>
+<para>This will show how high the characters go.
+</para>
+<screen>\newlength{\alphabetheight}
+\settoheight{\alphabetheight}{abcdefghijklmnopqrstuvwxyz}
+\the\alphabetheight
+</screen>
+<para>If there is no such length <replaceable>len</replaceable> then you get something like
+‘<literal>Undefined control sequence. <argument> \alphabetheight</literal>’.  If you
+leave the backslash out of <replaceable>len</replaceable>, as in
+<literal>\settoheight{alphabetheight}{...}</literal> then you get something like
+‘<literal>Missing number, treated as zero. <to be read again> \setbox</literal>’.
+</para>
 
-
 </sect1>
 <sect1 label="14.6" id="_005csettowidth">
-<title><literal>\settowidth{\<replaceable>len</replaceable>}{<replaceable>text</replaceable>}</literal></title>
+<title><literal>\settowidth</literal></title>
 
 <indexterm role="fn"><primary>\settowidth</primary></indexterm>
 
 <para>Synopsis:
 </para>
-<screen>\settowidth{\<replaceable>len</replaceable>}{<replaceable>text</replaceable>}
+<screen>\settowidth{<replaceable>len</replaceable>}{<replaceable>text</replaceable>}
 </screen>
-<para>The <literal>\settowidth</literal> command sets the value of the command <replaceable>\len</replaceable>
-to the width of the <replaceable>text</replaceable> argument.
+<para>Set the length <replaceable>len</replaceable> to the width of the box that &latex; gets on
+typesetting the <replaceable>text</replaceable> argument.  The length name <replaceable>len</replaceable> must
+begin with a backslash, <literal>\</literal>.
 </para>
+<para>This measures the width of the lowercase ASCII alphabet.
+</para>
+<screen>\newlength{\alphabetwidth}
+\settowidth{\alphabetwidth}{abcdefghijklmnopqrstuvwxyz}
+\the\alphabetwidth
+</screen>
+<para>If there is no such length <replaceable>len</replaceable> then you get something like
+‘<literal>Undefined control sequence. <argument> \alphabetwidth</literal>’.  If you
+leave the backslash out of <replaceable>len</replaceable>, as in
+<literal>\settoheight{alphabetwidth}{...}</literal> then you get something like
+‘<literal>Missing number, treated as zero. <to be read again> \setbox</literal>’.
+</para>
 
-</sect1>
-<sect1 label="14.7" id="Predefined-lengths">
-<title>Predefined lengths</title>
+<!-- @node Predefined lengths -->
+<!-- @section Predefined lengths -->
 
-<indexterm role="cp"><primary>lengths, predefined</primary></indexterm>
-<indexterm role="cp"><primary>predefined lengths</primary></indexterm>
+<!-- @cindex lengths, predefined -->
+<!-- @cindex predefined lengths -->
 
-<para><literal>\width</literal>
-<indexterm role="fn"><primary>\width</primary></indexterm>
-</para>
-<para><literal>\height</literal>
-<indexterm role="fn"><primary>\height</primary></indexterm>
-</para>
-<para><literal>\depth</literal>
-<indexterm role="fn"><primary>\depth</primary></indexterm>
-</para>
-<para><literal>\totalheight</literal>
-<indexterm role="fn"><primary>\totalheight</primary></indexterm>
-</para>
-<para>These length parameters can be used in the arguments of the box-making
-commands (see <link linkend="Boxes">Boxes</link>).  They specify the natural width, etc., of
-the text in the box. <literal>\totalheight</literal> equals <inlineequation><mathphrase><literal>\height</literal> +
-<literal>\depth</literal></mathphrase></inlineequation>. To make a box with the text stretched to double the
-natural size, e.g., say
-</para>
-<screen>\makebox[2\width]{Get a stretcher}
-</screen>
+<!-- @code{\width} -->
+<!-- @findex \width -->
 
+<!-- @code{\height} -->
+<!-- @findex \height -->
+
+<!-- @code{\depth} -->
+<!-- @findex \depth -->
+
+<!-- @code{\totalheight} -->
+<!-- @findex \totalheight -->
+
+<!-- These length parameters can be used in the arguments of the box-making -->
+<!-- commands (@pxref{Boxes}).  They specify the natural width, etc., of the -->
+<!-- text in the box. @code{\totalheight} equals -->
+<!-- @math{@code{@backslashchar{}height} + @code{@backslashchar{}depth}}. To -->
+<!-- make a box with the text stretched to double the natural size, e.g., say -->
+
+<!-- @example -->
+<!-- \makebox[2\width]@{Get a stretcher@} -->
+<!-- @end example -->
+
+
 </sect1>
 </chapter>
 <chapter label="15" id="Making-paragraphs">
@@ -7154,59 +9183,193 @@
 <indexterm role="cp"><primary>making paragraphs</primary></indexterm>
 <indexterm role="cp"><primary>paragraphs</primary></indexterm>
 
-<para>A paragraph is ended by one or more completely blank lines—lines not
-containing even a <literal>%</literal>.  A blank line should not appear where a new
-paragraph cannot be started, such as in math mode or in the argument of
-a sectioning command.
+<para>Once &latex; has all of a paragraph’s contents it divides it into
+lines, in a way that is optimized over the entire paragraph (see <link linkend="Line-breaking">Line
+breaking</link>).  To end the current paragraph, put an empty line.
 </para>
+<screen>It is a truth universally acknowledged, that a single man in possession
+of a good fortune, must be in want of a wife.
 
+However little known the feelings or views of such a man may be on his
+first entering a neighbourhood, this truth is so well fixed in the minds
+of the surrounding families, that he is considered the rightful property
+of some one or other of their daughters.
 
-<sect1 label="15.1" id="_005cindent">
-<title><literal>\indent</literal></title>
+``My dear Mr. Bennet,'' said his lady to him one day,
+``have you heard that Netherfield Park is let at last?''
+</screen>
+<para>The separator lines must be empty, including not containing a comment
+character, <literal>%</literal>.
+</para>
+<para>There are places where a new paragraph is not permitted.  Don’t put a
+blank line in math mode (see <link linkend="Modes">Modes</link>); here the line before the
+<literal>\end{equation}</literal>
+</para>
+<screen>\begin{equation}
+  2^{|S|} > |S|
 
-<indexterm role="fn"><primary>\indent</primary></indexterm>
-<indexterm role="fn"><primary>\parindent</primary></indexterm>
-<indexterm role="cp"><primary>indent, forcing</primary></indexterm>
+\end{equation}
+</screen>
+<para>will get you the error ‘<literal>Missing $ inserted</literal>’.  Similarly, the blank
+line in this <literal>section</literal> argument
+</para>
+<screen>\section{aaa
 
-<para><literal>\indent</literal> produces a horizontal space whose width equals to the
-<literal>\parindent</literal> length, the normal paragraph indentation.  It is used
-to add paragraph indentation where it would otherwise be suppressed.
+bbb}
+</screen>
+<para>gets ‘<literal>Runaway argument? {aaa ! Paragraph ended before \@sect was
+complete</literal>’.
 </para>
-<para>The default value for <literal>\parindent</literal> is <literal>1em</literal> in two-column
-mode, otherwise <literal>15pt</literal> for <literal>10pt</literal> documents, <literal>17pt</literal> for
-<literal>11pt</literal>, and <literal>1.5em</literal> for <literal>12pt</literal>.
+
+
+
+<sect1 label="15.1" id="_005cpar">
+<title><literal>\par</literal></title>
+
+<indexterm role="fn"><primary>\par</primary></indexterm>
+<indexterm role="cp"><primary>paragraph, ending</primary></indexterm>
+
+<para>Synopsis (note that while reading the input &tex;, converts two
+consecutive newlines to a <literal>\par</literal>):
 </para>
+<screen>\par
+</screen>
+<para>End the current paragraph.  The usual way to separate paragraphs is with
+a blank line but the <literal>\par</literal> command is entirely equivalent.  This
+command is robust (see <link linkend="_005cprotect">\protect</link>).
+</para>
+<para>This example uses <literal>\par</literal> rather than a blank line simply for
+readability.
+</para>
+<screen>\newcommand{\syllabusLegalese}{%
+  \whatCheatingIs\par\whatHappensWhenICatchYou}
+</screen>
+<para>The <literal>\par</literal> command does nothing in LR mode or a vertical mode but
+it terminates paragraph mode, bringing &latex; to vertical mode
+(see <link linkend="Modes">Modes</link>).
+</para>
+<para>You cannot use the <literal>\par</literal> command in math mode or in the argument
+of many commands, such as the <literal>\section</literal> command (see <link linkend="Making-paragraphs">Making
+paragraphs</link> and see <link linkend="_005cnewcommand-_0026-_005crenewcommand">\newcommand & \renewcommand</link>).
+</para>
+<para>The <literal>\par</literal> command differs from the <literal>\paragraph</literal> command in
+that the latter is, like <literal>\section</literal> or <literal>\subsection</literal>, a
+sectioning unit used by the standard &latex; documents.
+</para>
+<para>The <literal>\par</literal> command differs from <literal>\newline</literal> and the line break
+double backslash, <literal>\\</literal>, in that \par ends the paragraph not just
+the line.  It also triggers the addition of the between-paragraph
+vertical space <literal>\parskip</literal> (see <link linkend="_005cparindent-_0026-_005cparskip">\parindent & \parskip</link>).
+</para>
+<para>The output from this example
+</para>
+<screen>xyz
 
+\setlength{\parindent}{3in}
+\setlength{\parskip}{5in}
+\noindent test\indent test1\par test2 
+</screen>
+<para>is: after ‘<literal>xyz</literal>’ there is a vertical skip of 5 inches and then
+‘<literal>test</literal>’ appears, aligned with the left margin.  On the same line,
+there is an empty horizontal space of 3 inches and then
+‘<literal>test1</literal>’ appears.  Finally. there is a vertical space of
+5 inches, followed by a fresh paragraph with a paragraph indent of
+3 inches, and then &latex; puts the text ‘<literal>test2</literal>’.
+</para>
+
 </sect1>
-<sect1 label="15.2" id="_005cnoindent">
-<title><literal>\noindent</literal></title>
+<sect1 label="15.2" id="_005cindent-_0026-_005cnoindent">
+<title><literal>\indent</literal> & <literal>\noindent</literal></title>
 
+<indexterm role="fn"><primary>\indent</primary></indexterm>
 <indexterm role="fn"><primary>\noindent</primary></indexterm>
-<indexterm role="cp"><primary>indent, suppressing</primary></indexterm>
+<indexterm role="fn"><primary>\parindent</primary></indexterm>
+<indexterm role="cp"><primary>indent, forcing</primary></indexterm>
 
-<para>When used at the beginning of the paragraph, this command suppresses any
-paragraph indentation, as in this example.
+<para>Synopsis:
 </para>
+<screen>\indent
+</screen>
+<para>or
+</para>
+<screen>\noindent
+</screen>
+<para>Go into horizontal mode (see <link linkend="Modes">Modes</link>).  The <literal>\indent</literal> command
+first outputs an empty box whose width is <literal>\parindent</literal>.  These
+commands are robust (see <link linkend="_005cprotect">\protect</link>).
+</para>
+<para>Ordinarily you create a new paragraph by putting in a blank line.
+See <link linkend="_005cpar">\par</link> for the difference between this command and <literal>\par</literal>.  To
+start a paragraph without an indent, or to continue an interrupted
+paragraph, use <literal>\noindent</literal>.
+</para>
+<para>In the middle of a paragraph the <literal>\noindent</literal> command has no effect,
+because &latex; is already in horizontal mode there.  The
+<literal>\indent</literal> command’s only effect is to output a space.
+</para>
+<para>This example starts a fresh paragraph.
+</para>
 <screen>... end of the prior paragraph.
 
 \noindent This paragraph is not indented.
 </screen>
-<para>It has no effect when used in the middle of a paragraph.
+<para>and this continues an interrupted paragraph.
 </para>
-<para>To eliminate paragraph indentation in an entire document, put
-<literal>\setlength{\parindent}{0pt}</literal> in the preamble.
+<screen>The data 
+
+\begin{center}
+  \begin{tabular}{rl} ... \end{tabular}
+\end{center}
+
+\noindent shows this clearly.
+</screen>
+<para>To omit indentation in the entire document put
+<literal>\setlength{\parindent}{0pt}</literal> in the preamble.  If you do that,
+you may want to also set the length of spaces between paragraphs,
+<literal>\parskip</literal> (see <link linkend="_005cparindent-_0026-_005cparskip">\parindent & \parskip</link>).
 </para>
+<indexterm role="cp"><primary>package, <literal>indentfirst</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>indentfirst</literal> package</primary></indexterm>
 
+<para>Default &latex; styles have the first paragraph after a section that is
+not indented, as is traditional typesetting in English.  To change that,
+look on CTAN for the package <literal>indentfirst</literal>.
+</para>
+
 </sect1>
-<sect1 label="15.3" id="_005cparskip">
-<title><literal>\parskip</literal></title>
+<sect1 label="15.3" id="_005cparindent-_0026-_005cparskip">
+<title><literal>\parindent</literal> & <literal>\parskip</literal></title>
 
+<indexterm role="fn"><primary>\parindent</primary></indexterm>
 <indexterm role="fn"><primary>\parskip</primary></indexterm>
+<indexterm role="cp"><primary>paragraph indentation</primary></indexterm>
 <indexterm role="cp"><primary>vertical space before paragraphs</primary></indexterm>
 
-<para><literal>\parskip</literal> is a rubber length defining extra vertical space added
-before each paragraph.  The default is <literal>0pt plus1pt</literal>.
+<para>Synopsis:
 </para>
+<screen>\setlength{\parskip}{<replaceable>horizontal len</replaceable>}
+\setlength{\parinden}{<replaceable>vertical len</replaceable>}
+</screen>
+<para>Both are a rubber lengths (see <link linkend="Lengths">Lengths</link>).  They give the indentation
+of ordinary paragraphs, not paragraphs inside minipages
+(see <link linkend="minipage">minipage</link>), and the vertical space between paragraphs.
+</para>
+<para>This, put in the preamble,
+</para>
+<screen>\setlength{\parindent}{0em}
+\setlength{\parskip}{1ex}
+</screen>
+<para>arranges that the document will have paragraphs that are not indented,
+but instead are vertically separated by about the height of a lowercase
+‘<literal>x</literal>’.
+</para>
+<para>In standard &latex; documents, the default value for <literal>\parindent</literal>
+in one-column documents is <literal>15pt</literal> when the default text size is
+<literal>10pt</literal> , <literal>17pt</literal> for <literal>11pt</literal>, and <literal>1.5em</literal> for
+<literal>12pt</literal>.  In two-column documents it is <literal>1em</literal>.  The default
+value for <literal>\parskip</literal> in &latex;’s standard document styles is
+<literal>0pt plus1pt</literal>.
+</para>
 
 </sect1>
 <sect1 label="15.4" id="Marginal-notes">
@@ -7217,45 +9380,50 @@
 <indexterm role="cp"><primary>remarks in the margin</primary></indexterm>
 <indexterm role="fn"><primary>\marginpar</primary></indexterm>
 
-<para>Synopsis:
+<para>Synopsis, one of:
 </para>
-<screen>\marginpar[<replaceable>left</replaceable>]{<replaceable>right</replaceable>}
+<screen>\marginpar{<replaceable>right</replaceable>}
+\marginpar[<replaceable>left</replaceable>]{<replaceable>right</replaceable>}
 </screen>
-<para>The <literal>\marginpar</literal> command creates a note in the margin.  The first
-line of the note will have the same baseline as the line in the text
-where the <literal>\marginpar</literal> occurs.
+<para>Create a note in the margin.  The first line of the note will have the
+same baseline as the line in the text where the <literal>\marginpar</literal>
+occurs.
 </para>
-<para>When you only specify the mandatory argument <replaceable>right</replaceable>, the text
-will be placed
+<para>The margin that &latex; uses for the note depends on the current layout
+(see <link linkend="Document-class-options">Document class options</link>) and also on <literal>\reversemarginpar</literal>
+(see below).  If you are using one-sided layout (document option
+<literal>oneside</literal>) then it goes in the right margin.  If you are using
+two-sided layout (document option <literal>twoside</literal>) then it goes in the
+outside margin.  If you are in two-column layout (document option
+<literal>twocolumn</literal>) then it goes in the nearest margin.
 </para>
-<itemizedlist><listitem><para>in the right margin for one-sided layout (option <literal>oneside</literal>, see <link linkend="Document-class-options">Document class options</link>);
-</para></listitem><listitem><para>in the outside margin for two-sided layout (option <literal>twoside</literal>, see <link linkend="Document-class-options">Document class options</link>);
-</para></listitem><listitem><para>in the nearest margin for two-column layout (option <literal>twocolumn</literal>, see <link linkend="Document-class-options">Document class options</link>).
-</para></listitem></itemizedlist>
 <indexterm role="fn"><primary>\reversemarginpar</primary></indexterm>
 <indexterm role="fn"><primary>\normalmarginpar</primary></indexterm>
-<para>The command <literal>\reversemarginpar</literal> places subsequent marginal notes
-in the opposite (inside) margin.  <literal>\normalmarginpar</literal> places them
-in the default position.
+<para>If you declare <literal>\reversemarginpar</literal> then &latex; will place
+subsequent marginal notes in the opposite margin to that given in the
+prior paragraph.  Revert that to the default position with
+<literal>\normalmarginpar</literal>.
 </para>
-<para>When you specify both arguments, <replaceable>left</replaceable> is used for the left
-margin, and <replaceable>right</replaceable> is used for the right margin.
+<para>When you specify the optional argument <replaceable>left</replaceable> then it is used for a
+note in the left margin, while the mandatory argument <replaceable>right</replaceable> is
+used for a note in the the right margin.
 </para>
-<para>The first word will normally not be hyphenated; you can enable
-hyphenation there by beginning the node with <literal>\hspace{0pt}</literal>.
+<para>Normally, a note’s first word will not be hyphenated.  You can enable
+hyphenation there by beginning <replaceable>left</replaceable> or <replaceable>right</replaceable> with
+<literal>\hspace{0pt}</literal>.
 </para>
 <para>These parameters affect the formatting of the note:
 </para>
 <variablelist><varlistentry><term><indexterm role="fn"><primary>\marginparpush</primary></indexterm><literal>\marginparpush</literal>
-</term><listitem><para>Minimum vertical space between notes; default ‘<literal>7pt</literal>’ for
+</term><listitem><anchor id="marginal-notes-marginparpush"/><para>Minimum vertical space between notes; default ‘<literal>7pt</literal>’ for
 ‘<literal>12pt</literal>’ documents, ‘<literal>5pt</literal>’ else.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\marginparsep</primary></indexterm><literal>\marginparsep</literal>
-</term><listitem><para>Horizontal space between the main text and the note; default
+</term><listitem><anchor id="marginal-notes-marginparsep"/><para>Horizontal space between the main text and the note; default
 ‘<literal>11pt</literal>’ for ‘<literal>10pt</literal>’ documents, ‘<literal>10pt</literal>’ else.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\marginparwidth</primary></indexterm><literal>\marginparwidth</literal>
-</term><listitem><para>Width of the note itself; default for a one-sided ‘<literal>10pt</literal>’ document
+</term><listitem><anchor id="marginal-notes-marginparwidth"/><para>Width of the note itself; default for a one-sided ‘<literal>10pt</literal>’ document
 is ‘<literal>90pt</literal>’, ‘<literal>83pt</literal>’ for ‘<literal>11pt</literal>’, and ‘<literal>68pt</literal>’ for
 ‘<literal>12pt</literal>’; ‘<literal>17pt</literal>’ more in each case for a two-sided document.
 In two column mode, the default is ‘<literal>48pt</literal>’.
@@ -7286,53 +9454,107 @@
 <indexterm role="fn"><primary><literal>equation</literal> environment</primary></indexterm>
         
 
-<para>There are three environments that put &latex; in math mode:
+<para>Produce mathematical text by putting &latex; into math mode or display
+math mode (see <link linkend="Modes">Modes</link>).  This example shows both.
 </para>
-<variablelist><varlistentry><term><literal>math</literal>
-</term><listitem><para>For formulas that appear right in the text.
-</para></listitem></varlistentry><varlistentry><term><literal>displaymath</literal>
-</term><listitem><para>For formulas that appear on their own line.
-</para></listitem></varlistentry><varlistentry><term><literal>equation</literal>
-</term><listitem><para>The same as the displaymath environment except that it adds an equation
-number in the right margin.
-</para></listitem></varlistentry></variablelist>
-<indexterm role="fn"><primary>\(</primary></indexterm>
-<indexterm role="fn"><primary>\)</primary></indexterm>
-<indexterm role="fn"><primary>\[</primary></indexterm>
-<indexterm role="fn"><primary>\]</primary></indexterm>
-<para>The <literal>math</literal> environment can be used in both paragraph and LR mode,
-but the <literal>displaymath</literal> and <literal>equation</literal> environments can be used
-only in paragraph mode.  The <literal>math</literal> and <literal>displaymath</literal>
-environments are used so often that they have the following short forms:
+<screen>The wave equation for \( u \) is
+\begin{displaymath}
+  \frac{\partial^2u}{\partial t^2} = c^2\nabla^2u
+\end{displaymath}
+where \( \nabla^2 \) is the spatial Laplacian and \( c \) is constant.
+</screen>
+<para>Math mode is for inline mathematics.  In the above example it is invoked
+by the starting <literal>\(</literal> and finished by the matching ending <literal>\)</literal>.
+Display math mode is for displayed equations and here is invoked by the
+<literal>displaymath</literal> environment.  Note that any mathematical text
+whatever, including mathematical text consisting of just one character,
+is handled in math mode.
 </para>
-<screen>\(...\)   instead of   \begin{math}...\end{math}
-\[...\]   instead of   \begin{displaymath}...\end{displaymath}
+<para>When in math mode or display math mode, &latex; handles many aspects of
+your input text differently than in other text modes.  For example,
+</para>
+<screen>contrast x+y with \( x+y \)
 </screen>
-<indexterm role="fn"><primary>$</primary></indexterm>
-<para>In fact, the <literal>math</literal> environment is so common that it has an even
-shorter form:
+<para>in math mode the letters are in italics and the spacing around the plus
+sign is different.
 </para>
-<screen>$ ... $   instead of   \(...\)
+<para>There are three ways to make inline formulas, to put &latex; in math
+mode.
+</para>
+<screen>\( <replaceable>mathematical material</replaceable> \)
+$ <replaceable>mathematical material</replaceable> $
+\begin{math} <replaceable>mathematical material</replaceable> \end{math}
 </screen>
-<indexterm role="fn"><primary>\boldmath</primary></indexterm>
-<indexterm role="fn"><primary>\unboldmath</primary></indexterm>
-<para>The <literal>\boldmath</literal> command changes math letters and symbols to be in
-a bold font.  It is used <emphasis>outside</emphasis> of math mode.  Conversely, the
-<literal>\unboldmath</literal> command changes math glyphs to be in a normal font;
-it too is used <emphasis>outside</emphasis> of math mode.
+<para>The first form is preferred and the second is quite common, but the
+third form is rarely used.  You can sometimes use one and sometimes
+another, as in <literal>\(x\) and $y$</literal>.  You can use these in paragraph
+mode or in LR mode (see <link linkend="Modes">Modes</link>).
 </para>
-<!-- xx own section? Math fonts? -->
+<para>To make displayed formulas, put &latex; into display math mode with
+either:
+</para>
+<screen>\begin{displaymath}
+  <replaceable>mathematical material</replaceable>
+\end{displaymath}
+</screen>
+<para>or
+</para>
+<screen>\begin{equation}
+  <replaceable>mathematical material</replaceable>
+\end{equation}
+</screen>
+<para>(see <link linkend="displaymath">displaymath</link>, see <link linkend="equation">equation</link>).  The only difference is that
+with the <literal>equation</literal> environment, &latex; puts a formula number
+alongside the formula.  The construct <literal>\[ <replaceable>math</replaceable> \]</literal> is
+equivalent to <literal>\begin{displaymath} <replaceable>math</replaceable>
+\end{displaymath}</literal>.  These environments can only be used in paragraph
+mode (see <link linkend="Modes">Modes</link>).
+</para>
 <indexterm role="fn"><primary>\displaystyle</primary></indexterm>
-<para>The <literal>\displaystyle</literal> declaration forces the size and style of the
-formula to be that of <literal>displaymath</literal>, e.g., with limits above and
-below summations.  For example:
+<para>The two mathematics modes are similar, but there are some differences.
+One involves the placement of subscripts and superscripts; in display
+math mode they are further apart and in inline math mode they are closer
+together.
 </para>
-<screen>$\displaystyle \sum_{n=0}^\infty x_n $
+<para>Sometimes you want the display math typographical treatment to happen in
+the inline math mode.  For this, the <literal>\displaystyle</literal> declaration
+forces the size and style of the formula to be that of
+<literal>displaymath</literal>.  Thus <literal>\(\displaystyle \sum_{n=0}^\infty
+x_n\)</literal> will have the limits above and below the summation sign, not next
+to it.  Another example is that
+</para>
+<screen>\begin{tabular}{r|cc}
+  \textsc{Name}  &\textsc{Series}  &\textsc{Sum}  \\  \hline
+  Arithmetic     &\( a+(a+b)+(a+2b)+\cdots+(a+(n-1)b) \)
+                   &\( na+(n-1)n\cdot\frac{b}{2}\)  \\
+  Geometric      &\( a+ab+ab^2+\cdots+ab^{n-1} \)
+                   &\(\displaystyle a\cdot\frac{1-b^n}{1-b}\)  \\
+\end{tabular}
 </screen>
-<!-- xx see also \cal, \mathcal -->
+<para>because it has no <literal>\displaystyle</literal>, the ‘<literal>Arithmetic</literal>’ line’s
+fraction will be scrunched.  But, because of its <literal>\displaystyle</literal>,
+the ‘<literal>Geometric</literal>’ line’s fraction will be easy to read, with
+characters the same size as in the rest of the line.
+</para>
+<indexterm role="cp"><primary>package, <literal>amsmath</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>amsmath</literal> package</primary></indexterm>
 
+<indexterm role="cp"><primary>package, <literal>amsfonts</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>amsfonts</literal> package</primary></indexterm>
 
+<indexterm role="cp"><primary>package, <literal>mathtools</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>mathtools</literal> package</primary></indexterm>
 
+<para>The American Mathematical Society has made freely available a set of
+packages that greatly expand your options for writing mathematics,
+<filename>amsmath</filename> and <filename>amssymb</filename> (also be aware of the <filename>mathtools</filename>
+package that is an extension to, and loads, <filename>amsmath</filename>).  New
+documents that will have mathematical text should use these packages.
+Descriptions of these packages is outside the scope of this document;
+see their documentation on CTAN.
+</para>
+
+
 <sect1 label="16.1" id="Subscripts-_0026-superscripts">
 <title>Subscripts & superscripts</title>
 
@@ -7342,40 +9564,71 @@
 <indexterm role="fn"><primary>_</primary></indexterm>
 <indexterm role="fn"><primary>^</primary></indexterm>
 
-<para>In math mode, use the caret character <literal>^</literal> to make the
-<replaceable>exp</replaceable> appear as a superscript: <literal>^{<replaceable>exp</replaceable>}</literal>.
-Similarly, in math mode, underscore <literal>_{<replaceable>exp</replaceable>}</literal> makes a
-subscript out of <replaceable>exp</replaceable>.
+<para>Synopsis (in math mode or display math mode), one of:
 </para>
-<para>In this example the <literal>0</literal> and <literal>1</literal> appear as subscripts while the
-<literal>2</literal> is a superscript.
+<screen><replaceable>base</replaceable>^<replaceable>exp</replaceable>
+<replaceable>base</replaceable>^{<replaceable>exp</replaceable>}
+</screen>
+<para>or, one of:
 </para>
-<screen>\( (x_0+x_1)^2 \)
+<screen><replaceable>base</replaceable>_<replaceable>exp</replaceable>
+<replaceable>base</replaceable>_{<replaceable>exp</replaceable>}
 </screen>
-<para>To have more than one character in <replaceable>exp</replaceable> use curly braces as in
-<literal>e^{-2x}</literal>.
+<para>Make <replaceable>exp</replaceable> appear as a superscript of <replaceable>base</replaceable> (with the caret
+character, <literal>^</literal>) or a subscript (with
+underscore, <literal>_</literal>).
 </para>
-<para>&latex; handles superscripts on superscripts, and all of that stuff, in
-the natural way, so expressions such as <literal>e^{x^2}</literal> and
-<literal>x_{a_0}</literal> will look right.  It also does the right thing when
-something has both a subscript and a superscript.  In this example the
-<literal>0</literal> appears at the bottom of the integral sign while the <literal>10</literal>
-appears at the top.
-</para> 
-<screen>\int_0^{10} x^2 \,dx
+<para>In this example the <literal>0</literal>’s and <literal>1</literal>’s are subscripts while the
+<literal>2</literal>’s are superscripts.
+</para>
+<screen>\( (x_0+x_1)^2 \leq (x_0)^2+(x_1)^2 \)
 </screen>
-<para>You can put a superscript or subscript before a symbol with a construct
-such as <literal>{}_t K^2</literal> in math mode (the initial <literal>{}</literal> prevents
-the prefixed subscript from being attached to any prior symbols in the
-expression).
+<para>To have the subscript or superscript contain more than one character,
+surround the expression with curly braces, as in <literal>e^{-2x}</literal>.
+This example’s fourth line shows curly braces used to group an expression
+for the exponent.
 </para>
-<para>Outside of math mode, a construct like <literal>A
-test$_\textnormal{subscript}$</literal> will produce a subscript typeset in
-text mode, not math mode.  Note that there are packages specialized for
-writing Chemical formulas such as <filename>mhchem</filename>.
-<!-- xx display mode -->
+<screen>\begin{displaymath}
+  (3^3)^3=27^3=19\,683
+  \qquad
+  3^{(3^3)}=3^{27}=7\,625\,597\,484\,987
+\end{displaymath}
+</screen>
+<para>&latex; knows how to handle a superscript on a superscript, or a
+subscript on a subscript, or supers on subs, or subs on supers.  So,
+expressions such as <literal>e^{x^2}</literal> and <literal>x_{i_0}</literal> give correct
+output.  Note the use in those expressions of curly braces to give the
+<replaceable>base</replaceable> a determined <replaceable>exp</replaceable>.  If you enter <literal>\(3^3^3\)</literal> then
+you get ‘<literal>Double superscript</literal>’.
 </para>
+<para>&latex; does the right thing when something has both a subscript and a
+superscript.  In this example the integral has both.  They come out in
+the correct place without any author intervention.
+</para>
+<screen>\begin{displaymath}
+  \int_{x=a}^b f'(x)\,dx = f(b)-f(a)
+\end{displaymath}
+</screen>
+<para>Note the parentheses around <literal>x=a</literal> to make the entire expression a
+subscript.
+</para>
+<para>To put a superscript or subscript before a symbol, use a construct like
+<literal>{}_t K^2</literal>.  The empty curly braces <literal>{}</literal> give the
+subscript something to attach to and keeps it from accidentally
+attaching to a prior symbols.
+</para>
+<para>Using the subscript or superscript command outside of math mode or
+display math mode, as in <literal>the expression x^2</literal>, will get you
+the error ‘<literal>Missing $ inserted</literal>’.
+</para>
+<indexterm role="cp"><primary>package, <literal>mhchem</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>mhchem</literal> package</primary></indexterm>
 
+<para>A common reason to want subscripts outside of a mathematics mode is to
+typeset chemical formulas.  There are packages for that such as
+<filename>mhchem</filename>; see CTAN.
+</para>
+
 </sect1>
 <sect1 label="16.2" id="Math-symbols">
 <title>Math symbols</title>
@@ -7384,20 +9637,23 @@
 <indexterm role="cp"><primary>symbols, math</primary></indexterm>
 <indexterm role="cp"><primary>greek letters</primary></indexterm>
 
-<para>&latex; provides almost any mathematical symbol you’re likely to need.
-For example, if you include <literal>$\pi$</literal> in your source, you will get
-the pi symbol &#x03C0;.
-</para> 
-<para>Below is a list of commonly-available symbols.  It is by no means an
-exhaustive list.  Each symbol here is described with a short phrase, and
-its symbol class (which determines the spacing around it) is given in
-parenthesis.  Unless said otherwise, the commands for these symbols can
-be used only in math mode.
+<indexterm role="cp"><primary>package, <literal>symbols</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>symbols</literal> package</primary></indexterm>
+
+
+<para>&latex; provides almost any mathematical or technical symbol that
+anyone uses.  For example, if you include <literal>$\pi$</literal> in your source,
+you will get the pi symbol &#x03C0;.  See the <filename>Comprehensive
+&latex; Symbol List</filename> at
+<ulink url="https://ctan.org/tex-archive/info/symbols/comprehensive/">https://ctan.org/tex-archive/info/symbols/comprehensive/</ulink>.
 </para>
-<para>To redefine a command so that it can be used whatever the current mode,
-see <link linkend="_005censuremath">\ensuremath</link>.
+<para>Here is a list of commonly-used symbols.  It is by no means exhaustive.
+Each symbol is described with a short phrase, and its symbol class,
+which determines the spacing around it, is given in parenthesis.  Unless
+said otherwise, the commands for these symbols can be used only in math
+mode.  To redefine a command so that it can be used whatever the current
+mode, see <link linkend="_005censuremath">\ensuremath</link>.
 </para>
-
 <!-- xx Add Negation: @code{} for negations of relevant symbols -->
 <!-- Useful: http://www.w3.org/TR/WD-math-970515/section6.html -->
 
@@ -7408,7 +9664,7 @@
 </term><listitem><para>&#x2135; Aleph, transfinite cardinal (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\alpha</primary></indexterm><literal>\alpha</literal>
-</term><listitem><para>&#x03B1; Lower case Greek letter alpha (ordinary).
+</term><listitem><para>&#x03B1; Lowercase Greek letter alpha (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\amalg</primary></indexterm><literal>\amalg</literal>
 </term><listitem><para>&#x2A3F; Disjoint union (binary)
@@ -7435,7 +9691,7 @@
 <literal>\textbackslash</literal> for backslash outside of math mode.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\beta</primary></indexterm><literal>\beta</literal>
-</term><listitem><para>&#x03B2; Lower case Greek letter beta (ordinary).
+</term><listitem><para>&#x03B2; Lowercase Greek letter beta (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\bigcap</primary></indexterm><literal>\bigcap</literal>
 </term><listitem><para>&#x22C2; Variable-sized, or n-ary, intersection (operator). Similar:
@@ -7505,7 +9761,7 @@
 dot <literal>\bullet</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\chi</primary></indexterm><literal>\chi</literal>
-</term><listitem><para>&#x03C7; Lower case Greek chi (ordinary).
+</term><listitem><para>&#x03C7; Lowercase Greek chi (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\circ</primary></indexterm><literal>\circ</literal>
 </term><listitem><para>&#x2218; Function composition, ring operator (binary).  Similar:
@@ -7516,8 +9772,8 @@
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\complement</primary></indexterm><literal>\complement</literal>
 </term><listitem><para>&#x2201; Set complement, used as a superscript as in
-<literal>$S^\complement$</literal> (ordinary).  Not available in plain &tex;. In &latex; you need to load the <filename>amssymb</filename> package. Also
-used: <literal>$S^{\mathsf{c}}$</literal> or <literal>$\bar{S}$</literal>.
+<literal>$S^\complement$</literal> (ordinary).  Not available in plain &tex;. In &latex; you need to load the <filename>amssymb</filename> package. Also used:
+<literal>$S^{\mathsf{c}}$</literal> or <literal>$\bar{S}$</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\cong</primary></indexterm><literal>\cong</literal>
 </term><listitem><para>&#x2245; Congruent (relation).
@@ -7540,17 +9796,16 @@
 </term><listitem><para>&#x2021; Double dagger relation (binary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\Delta</primary></indexterm><literal>\Delta</literal>
-</term><listitem><para>&#x0394; Greek upper case delta, used for increment (ordinary).
+</term><listitem><para>&#x0394; Greek uppercase delta, used for increment (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\delta</primary></indexterm><literal>\delta</literal>
-</term><listitem><para>&#x03B4; Greek lower case delta (ordinary).
+</term><listitem><para>&#x03B4; Greek lowercase delta (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\Diamond</primary></indexterm><literal>\Diamond</literal>
 </term><listitem><para>&#x25C7; Large diamond operator (ordinary).  Not available in plain &tex;. In &latex; you need to load the <filename>amssymb</filename> package.
-<!-- bb Best Unicode equivalent? -->
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\diamond</primary></indexterm><literal>\diamond</literal>
-</term><listitem><para>&#x22C4; Diamond operator, or diamond bullet (binary).  Similar: large
+</term><listitem><para>&#x22C4; Diamond operator (binary).  Similar: large
 diamond <literal>\Diamond</literal>, circle bullet <literal>\bullet</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\diamondsuit</primary></indexterm><literal>\diamondsuit</literal>
@@ -7564,12 +9819,12 @@
 to <literal>\Doteq</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\downarrow</primary></indexterm><literal>\downarrow</literal>
-</term><listitem><para>&#x2193; Down arrow, converges (relation).  Similar: double line down
-arrow <literal>\Downarrow</literal>.
+</term><listitem><para>&#x2193; Down arrow, converges (relation).  Similar:
+<literal>\Downarrow</literal> double line down arrow.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\Downarrow</primary></indexterm><literal>\Downarrow</literal>
-</term><listitem><para>&#x21D3; Double line down arrow (relation).  Similar: single line down
-arrow <literal>\downarrow</literal>.
+</term><listitem><para>&#x21D3; Double line down arrow (relation).  Similar:
+<literal>\downarrow</literal> single line down arrow.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\ell</primary></indexterm><literal>\ell</literal>
 </term><listitem><para>&#x2113; Lowercase cursive letter l (ordinary).
@@ -7580,7 +9835,7 @@
 <!-- bb Why Unicode has \revemptyset but no \emptyset? -->
 </para>	
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\epsilon</primary></indexterm><literal>\epsilon</literal>
-</term><listitem><para>&#x03F5; Lower case lunate epsilon (ordinary). Similar to
+</term><listitem><para>&#x03F5; Lowercase lunate epsilon (ordinary). Similar to
 Greek text letter. More widely used in mathematics is the script small
 letter epsilon <literal>\varepsilon</literal> &#x03B5;. Related:
 the set membership relation <literal>\in</literal> &#x2208;.
@@ -7591,7 +9846,7 @@
 </term><listitem><para>&#x2261; Equivalence (relation).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\eta</primary></indexterm><literal>\eta</literal>
-</term><listitem><para>&#x03B7; Lower case Greek letter (ordinary).
+</term><listitem><para>&#x03B7; Lowercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\exists</primary></indexterm><literal>\exists</literal>
 </term><listitem><para>&#x2203; Existential quantifier (ordinary).
@@ -7606,10 +9861,10 @@
 </term><listitem><para>&#x2322; Downward curving arc (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\Gamma</primary></indexterm><literal>\Gamma</literal>
-</term><listitem><para>&#x0393; Upper case Greek letter (ordinary).
+</term><listitem><para>&#x0393; uppercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\gamma</primary></indexterm><literal>\gamma</literal>
-</term><listitem><para>&#x03B3; Lower case Greek letter (ordinary).
+</term><listitem><para>&#x03B3; Lowercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\ge</primary></indexterm><literal>\ge</literal>
 </term><listitem><para>&#x2265; Greater than or equal to (relation).  This is a synonym
@@ -7646,8 +9901,13 @@
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\Im</primary></indexterm><literal>\Im</literal>
 </term><listitem><para>&#x2111; Imaginary part (ordinary).  See: real part <literal>\Re</literal>.
 </para>
+</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\imath</primary></indexterm><literal>\imath</literal>
+</term><listitem><indexterm role="cp"><primary>dotless i, math</primary></indexterm>
+<para>Dotless i; used when you are putting an accent on an i (see <link linkend="Math-accents">Math
+accents</link>).
+</para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\in</primary></indexterm><literal>\in</literal>
-</term><listitem><para>&#x2208; Set element (relation).  See also: lower case lunate
+</term><listitem><para>&#x2208; Set element (relation).  See also: lowercase lunate
 epsilon <literal>\epsilon</literal>&#x03F5; and small letter script
 epsilon <literal>\varepsilon</literal>.
 </para>
@@ -7658,20 +9918,25 @@
 </term><listitem><para>&#x222B; Integral (operator).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\iota</primary></indexterm><literal>\iota</literal>
-</term><listitem><para>&#x03B9; Lower case Greek letter (ordinary).
+</term><listitem><para>&#x03B9; Lowercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\Join</primary></indexterm><literal>\Join</literal>
 </term><listitem><para>&#x2A1D; Condensed bowtie symbol (relation).  Not available in Plain
 &tex;.
 </para>
+</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\jmath</primary></indexterm><literal>\jmath</literal>
+</term><listitem><indexterm role="cp"><primary>dotless j, math</primary></indexterm>
+<para>Dotless j; used when you are putting an accent on a j (see <link linkend="Math-accents">Math
+accents</link>).
+</para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\kappa</primary></indexterm><literal>\kappa</literal>
-</term><listitem><para>&#x03BA; Lower case Greek letter (ordinary).
+</term><listitem><para>&#x03BA; Lowercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\Lambda</primary></indexterm><literal>\Lambda</literal>
-</term><listitem><para>&#x039B; Upper case Greek letter (ordinary).
+</term><listitem><para>&#x039B; uppercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\lambda</primary></indexterm><literal>\lambda</literal>
-</term><listitem><para>&#x03BB; Lower case Greek letter (ordinary).
+</term><listitem><para>&#x03BB; Lowercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\land</primary></indexterm><literal>\land</literal>
 </term><listitem><para>&#x2227; Logical and (binary).  This is a synonym for <literal>\wedge</literal>.
@@ -7792,7 +10057,7 @@
 </term><listitem><para>&#x2213; Minus or plus (relation).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\mu</primary></indexterm><literal>\mu</literal>
-</term><listitem><para>&#x03BC; Lower case Greek letter (ordinary).
+</term><listitem><para>&#x03BC; Lowercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\nabla</primary></indexterm><literal>\nabla</literal>
 </term><listitem><para>&#x2207; Hamilton’s del, or differential, operator (ordinary).
@@ -7820,20 +10085,20 @@
 of <literal>\in</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\not</primary></indexterm><literal>\not</literal>
-</term><listitem><para>&#x0020;&#x00A0;&#x0338; Long solidus, or slash, used to overstrike a
+</term><listitem><!-- the "@ "s put in spaces so the not slash doesn't hit the next char. -->
+<para>&#x0020;    Long solidus, or slash, used to overstrike a
 following operator (relation).
-<!-- Need blank space for it to overstrike -->
 </para>
-<para>Many negated operators that don’t require <literal>\not</literal> are available,
+<para>Many negated operators are available that don’t require <literal>\not</literal>,
 particularly with the <filename>amssymb</filename> package. For example, <literal>\notin</literal>
-is probably typographically preferable to <literal>\not\in</literal>.
+is typographically preferable to <literal>\not\in</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\notin</primary></indexterm><literal>\notin</literal>
 </term><listitem><para>&#x2209; Not an element of (relation).  Similar: not subset
 of <literal>\nsubseteq</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\nu</primary></indexterm><literal>\nu</literal>
-</term><listitem><para>&#x03BD; Lower case Greek letter (ordinary).
+</term><listitem><para>&#x03BD; Lowercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\nwarrow</primary></indexterm><literal>\nwarrow</literal>
 </term><listitem><para>&#x2196; North-west arrow (relation).
@@ -7843,13 +10108,14 @@
 operator <literal>\bigodot</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\oint</primary></indexterm><literal>\oint</literal>
-</term><listitem><para>&#x222E; Contour integral, integral with circle in the middle (operator).
+</term><listitem><para>&#x222E; Contour integral, integral with circle in the middle
+(operator).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\Omega</primary></indexterm><literal>\Omega</literal>
-</term><listitem><para>&#x03A9; Upper case Greek letter (ordinary).
+</term><listitem><para>&#x03A9; uppercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\omega</primary></indexterm><literal>\omega</literal>
-</term><listitem><para>&#x03C9; Lower case Greek letter (ordinary).
+</term><listitem><para>&#x03C9; Lowercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\ominus</primary></indexterm><literal>\ominus</literal>
 </term><listitem><para>&#x2296; Minus sign, or dash, inside a circle (binary).
@@ -7882,14 +10148,14 @@
 ordinary.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\phi</primary></indexterm><literal>\phi</literal>
-</term><listitem><para>&#x03D5; Lower case Greek letter (ordinary).  The variant form is
+</term><listitem><para>&#x03D5; Lowercase Greek letter (ordinary).  The variant form is
 <literal>\varphi</literal> &#x03C6;.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\Pi</primary></indexterm><literal>\Pi</literal>
-</term><listitem><para>&#x03A0; Upper case Greek letter (ordinary).
+</term><listitem><para>&#x03A0; uppercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\pi</primary></indexterm><literal>\pi</literal>
-</term><listitem><para>&#x03C0; Lower case Greek letter (ordinary).  The variant form is
+</term><listitem><para>&#x03C0; Lowercase Greek letter (ordinary).  The variant form is
 <literal>\varpi</literal> &#x03D6;.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\pm</primary></indexterm><literal>\pm</literal>
@@ -7919,14 +10185,14 @@
 </term><listitem><para>&#x221D; Is proportional to (relation)
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\Psi</primary></indexterm><literal>\Psi</literal>
-</term><listitem><para>&#x03A8; Upper case Greek letter (ordinary).
+</term><listitem><para>&#x03A8; uppercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\psi</primary></indexterm><literal>\psi</literal>
-</term><listitem><para>&#x03C8; Lower case Greek letter (ordinary).
+</term><listitem><para>&#x03C8; Lowercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\rangle</primary></indexterm><literal>\rangle</literal>
-</term><listitem><para>&#x27E9; Right angle, or sequence, bracket (closing). Similar: greater
-than <literal>></literal>.  Matches:<literal>\langle</literal>.
+</term><listitem><para>&#x27E9; Right angle, or sequence, bracket (closing).
+Similar: greater than <literal>></literal>. Matches:<literal>\langle</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\rbrace</primary></indexterm><literal>\rbrace</literal>
 </term><listitem><para>&#x007D; Right curly brace
@@ -7945,8 +10211,8 @@
 this, load the <filename>amsfonts</filename> package.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\restriction</primary></indexterm><literal>\restriction</literal>
-</term><listitem><para>&#x21BE; Restriction of a function
-(relation). Synonym: <literal>\upharpoonright</literal>.  Not available in plain &tex;. In &latex; you need to load the <filename>amssymb</filename> package.
+</term><listitem><para>&#x21BE; Restriction of a function (relation). Synonym:
+<literal>\upharpoonright</literal>.  Not available in plain &tex;. In &latex; you need to load the <filename>amssymb</filename> package.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\revemptyset</primary></indexterm><literal>\revemptyset</literal>
 </term><listitem><para>&#x29B0; Reversed empty set symbol (ordinary).  Related:
@@ -7959,45 +10225,50 @@
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\rhd</primary></indexterm><literal>\rhd</literal>
 </term><listitem><para>&#x25C1; Arrowhead, that is, triangle, pointing right (binary).
 Not available in plain &tex;. In &latex; you need to load the <filename>amssymb</filename> package. For the normal subgroup symbol you should instead
-load <filename>amssymb</filename> and use <literal>\vartriangleright</literal> (which
-is a relation and so gives better spacing).
+load <filename>amssymb</filename> and use <literal>\vartriangleright</literal> (which is a
+relation and so gives better spacing).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\rho</primary></indexterm><literal>\rho</literal>
-</term><listitem><para>&#x03C1; Lower case Greek letter (ordinary).  The variant form is
+</term><listitem><para>&#x03C1; Lowercase Greek letter (ordinary).  The variant form is
 <literal>\varrho</literal> &#x03F1;.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\Rightarrow</primary></indexterm><literal>\Rightarrow</literal>
-</term><listitem><para>&#x21D2; Implies, right-pointing double line arrow (relation). Similar:
-right single-line arrow <literal>\rightarrow</literal>.
+</term><listitem><para>&#x21D2; Implies, right-pointing double line arrow
+(relation). Similar: right single-line arrow <literal>\rightarrow</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\rightarrow</primary></indexterm><literal>\rightarrow</literal>
-</term><listitem><para>&#x2192; Right-pointing single line arrow (relation). Synonym: <literal>\to</literal>. Similar: right double line arrow <literal>\Rightarrow</literal>.
+</term><listitem><para>&#x2192; Right-pointing single line arrow (relation).
+Synonym: <literal>\to</literal>. Similar: right double line
+arrow <literal>\Rightarrow</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\rightharpoondown</primary></indexterm><literal>\rightharpoondown</literal>
-</term><listitem><para>&#x21C1; Right-pointing harpoon with barb below the line (relation).
+</term><listitem><para>&#x21C1; Right-pointing harpoon with barb below
+the line (relation). 
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\rightharpoonup</primary></indexterm><literal>\rightharpoonup</literal>
-</term><listitem><para>&#x21C0; Right-pointing harpoon with barb above the line (relation).
+</term><listitem><para>&#x21C0; Right-pointing harpoon with barb above the
+line (relation).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\rightleftharpoons</primary></indexterm><literal>\rightleftharpoons</literal>
-</term><listitem><para>&#x21CC; Right harpoon up above left harpoon down (relation).
+</term><listitem><para>&#x21CC; Right harpoon up above left harpoon down
+(relation).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\searrow</primary></indexterm><literal>\searrow</literal>
 </term><listitem><para>&#x2198; Arrow pointing southeast (relation).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\setminus</primary></indexterm><literal>\setminus</literal>
-</term><listitem><para>&#x29F5; Set difference, reverse solidus or slash, like \
-(binary). Similar: backslash <literal>\backslash</literal> and also
+</term><listitem><para>&#x29F5; Set difference, reverse solidus or reverse slash,
+like \ (binary). Similar: backslash <literal>\backslash</literal> and also
 <literal>\textbackslash</literal> outside of math mode.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\sharp</primary></indexterm><literal>\sharp</literal>
 </term><listitem><para>&#x266F; Musical sharp (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\Sigma</primary></indexterm><literal>\Sigma</literal>
-</term><listitem><para>&#x03A3; Upper case Greek letter (ordinary).
+</term><listitem><para>&#x03A3; uppercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\sigma</primary></indexterm><literal>\sigma</literal>
-</term><listitem><para>&#x03C3; Lower case Greek letter (ordinary). The variant form is
+</term><listitem><para>&#x03C3; Lowercase Greek letter (ordinary). The variant form is
 <literal>\varsigma</literal> &#x03C2;.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\sim</primary></indexterm><literal>\sim</literal>
@@ -8038,15 +10309,15 @@
 superset <literal>\supset</literal>. Not available in plain &tex;. In &latex; you need to load the <filename>amssymb</filename> package.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\sqsupseteq</primary></indexterm><literal>\sqsupseteq</literal>
-</term><listitem><para>&#x2292; Square superset or equal symbol (binary). Similar: superset or
-equal <literal>\supseteq</literal>.
+</term><listitem><para>&#x2292; Square superset or equal symbol (binary).
+Similar: superset or equal <literal>\supseteq</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\star</primary></indexterm><literal>\star</literal>
-</term><listitem><para>&#x22C6; Five-pointed star, sometimes used as a general binary operation
-but sometimes reserved for cross-correlation (binary). Similar: the
-synonyms asterisk <literal>*</literal> and <literal>\ast</literal>, which are six-pointed,
-and more often appear as a superscript or subscript, as with the Kleene
-star.
+</term><listitem><para>&#x22C6; Five-pointed star, sometimes used as a general binary
+operation but sometimes reserved for cross-correlation (binary).
+Similar: the synonyms asterisk <literal>*</literal> and <literal>\ast</literal>, which
+are six-pointed, and more often appear as a superscript or subscript,
+as with the Kleene star.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\subset</primary></indexterm><literal>\subset</literal>
 </term><listitem><para>&#x2282; Subset (occasionally, is implied by) (relation).
@@ -8081,10 +10352,10 @@
 </term><listitem><para>&#x2199; Southwest-pointing  arrow (relation).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\tau</primary></indexterm><literal>\tau</literal>
-</term><listitem><para>&#x03C4; Lower case Greek letter (ordinary).
+</term><listitem><para>&#x03C4; Lowercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\theta</primary></indexterm><literal>\theta</literal>
-</term><listitem><para>&#x03B8; Lower case Greek letter (ordinary). The variant form is
+</term><listitem><para>&#x03B8; Lowercase Greek letter (ordinary). The variant form is
 <literal>\vartheta</literal> &#x03D1;.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\times</primary></indexterm><literal>\times</literal>
@@ -8115,16 +10386,16 @@
 relation and so gives better spacing).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\unlhd</primary></indexterm><literal>\unlhd</literal>
-</term><listitem><para>&#x22B4; Left-pointing not-filled underlined arrowhead, that
-is, triangle, with a line under (binary). Not available in plain &tex;. In &latex; you need to load the <filename>amssymb</filename> package.  For
-the normal subgroup symbol load <filename>amssymb</filename> and
+</term><listitem><para>&#x22B4; Left-pointing not-filled underlined arrowhead, that is,
+triangle, with a line under (binary). Not available in plain &tex;. In &latex; you need to load the <filename>amssymb</filename> package. For the
+normal subgroup symbol load <filename>amssymb</filename> and
 use <literal>\vartrianglelefteq</literal> (which is a relation and so gives
 better spacing).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\unrhd</primary></indexterm><literal>\unrhd</literal>
-</term><listitem><para>&#x22B5; Right-pointing not-filled underlined arrowhead, that
-is, triangle, with a line under (binary). Not available in plain &tex;. In &latex; you need to load the <filename>amssymb</filename> package.  For
-the normal subgroup symbol load <filename>amssymb</filename> and
+</term><listitem><para>&#x22B5; Right-pointing not-filled underlined arrowhead, that is,
+triangle, with a line under (binary). Not available in plain &tex;. In &latex; you need to load the <filename>amssymb</filename> package. For the
+normal subgroup symbol load <filename>amssymb</filename> and
 use <literal>\vartrianglerighteq</literal> (which is a relation and so gives
 better spacing).
 </para>
@@ -8144,12 +10415,14 @@
 arrow <literal>\updownarrow</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\updownarrow</primary></indexterm><literal>\updownarrow</literal>
-</term><listitem><para>&#x2195; Single-line upward-and-downward-pointing arrow (relation). Similar:
-double-line upward-and-downward-pointing arrow <literal>\Updownarrow</literal>.
+</term><listitem><para>&#x2195; Single-line upward-and-downward-pointing arrow
+(relation). Similar: double-line upward-and-downward-pointing
+arrow <literal>\Updownarrow</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\upharpoonright</primary></indexterm><literal>\upharpoonright</literal>
 </term><listitem><para>&#x21BE; Up harpoon, with barb on right side
-(relation). Synonym: <literal>\restriction</literal>.  Not available in plain &tex;. In &latex; you need to load the <filename>amssymb</filename> package.
+(relation). Synonym: <literal>\restriction</literal>.
+Not available in plain &tex;. In &latex; you need to load the <filename>amssymb</filename> package.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\uplus</primary></indexterm><literal>\uplus</literal>
 </term><listitem><para>&#x228E; Multiset union, a union symbol with a plus symbol in
@@ -8157,10 +10430,10 @@
 variable-sized operator <literal>\biguplus</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\Upsilon</primary></indexterm><literal>\Upsilon</literal>
-</term><listitem><para>&#x03A5; Upper case Greek letter (ordinary).
+</term><listitem><para>&#x03A5; uppercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\upsilon</primary></indexterm><literal>\upsilon</literal>
-</term><listitem><para>&#x03C5; Lower case Greek letter (ordinary).
+</term><listitem><para>&#x03C5; Lowercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\varepsilon</primary></indexterm><literal>\varepsilon</literal>
 </term><listitem><para>&#x03B5; Small letter script epsilon (ordinary).  This is
@@ -8169,28 +10442,28 @@
 membership <literal>\in</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\vanothing</primary></indexterm><literal>\vanothing</literal>
-</term><listitem><para>&#x2205; Empty set symbol. Similar:
-<literal>\emptyset</literal>. Related: <literal>\revemptyset</literal>. Not available in plain &tex;. In &latex; you need to load the <filename>amssymb</filename> package.
+</term><listitem><para>&#x2205; Empty set symbol. Similar: <literal>\emptyset</literal>. Related:
+<literal>\revemptyset</literal>. Not available in plain &tex;. In &latex; you need to load the <filename>amssymb</filename> package.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\varphi</primary></indexterm><literal>\varphi</literal>
-</term><listitem><para>&#x03C6; Variant on the lower case Greek letter (ordinary).
+</term><listitem><para>&#x03C6; Variant on the lowercase Greek letter (ordinary).
 The non-variant form is <literal>\phi</literal> &#x03D5;.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\varpi</primary></indexterm><literal>\varpi</literal>
-</term><listitem><para>&#x03D6; Variant on the lower case Greek letter (ordinary).
+</term><listitem><para>&#x03D6; Variant on the lowercase Greek letter (ordinary).
 The non-variant form is <literal>\pi</literal> &#x03C0;.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\varrho</primary></indexterm><literal>\varrho</literal>
-</term><listitem><para>&#x03F1; Variant on the lower case Greek letter (ordinary).
+</term><listitem><para>&#x03F1; Variant on the lowercase Greek letter (ordinary).
 The non-variant form is <literal>\rho</literal> &#x03C1;.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\varsigma</primary></indexterm><literal>\varsigma</literal>
-</term><listitem><para>&#x03C2; Variant on the lower case Greek letter
+</term><listitem><para>&#x03C2; Variant on the lowercase Greek letter
 (ordinary).  The non-variant form is
 <literal>\sigma</literal> &#x03C3;.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\vartheta</primary></indexterm><literal>\vartheta</literal>
-</term><listitem><para>&#x03D1; Variant on the lower case Greek letter
+</term><listitem><para>&#x03D1; Variant on the lowercase Greek letter
 (ordinary).  The non-variant form is
 <literal>\theta</literal> &#x03B8;.
 </para>
@@ -8208,34 +10481,35 @@
 </term><listitem><para>&#x2016; Vertical double bar (ordinary). Similar: vertical single
 bar <literal>\vert</literal>.
 </para>
-<para>For a norm symbol, you can use the <filename>mathtools</filename> package and add
-<literal>\DeclarePairedDelimiter\norm{\lVert}{\rVert}</literal> to your
-preamble. This gives you three command variants for double-line
-vertical bars that are correctly horizontally spaced: if in the
-document body you write the starred version <literal>$\norm*{M^\perp}$</literal>
-then the height of the vertical bars will match the height of the
-argument, whereas with <literal>\norm{M^\perp}</literal> the bars do not grow
-with the height of the argument but instead are the default height,
-and <literal>\norm[<replaceable>size command</replaceable>]{M^\perp}</literal> also gives bars that
-do not grow but are set to the size given in the <replaceable>size command</replaceable>,
-e.g., <literal>\Bigg</literal>.
+<para>For a norm symbol, you can use the <filename>mathtools</filename> package and put in
+your preamble
+<literal>\DeclarePairedDelimiter\norm{\lVert}{\rVert}</literal>. This gives you
+three command variants for double-line vertical bars that are correctly
+horizontally spaced: if in the document body you write the starred
+version <literal>$\norm*{M^\perp}$</literal> then the height of the vertical bars
+will match the height of the argument, whereas with
+<literal>\norm{M^\perp}</literal> the bars do not grow with the height of the
+argument but instead are the default height, and <literal>\norm[<replaceable>size
+command</replaceable>]{M^\perp}</literal> also gives bars that do not grow but are set to
+the size given in the <replaceable>size command</replaceable>, e.g., <literal>\Bigg</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\vert</primary></indexterm><literal>\vert</literal>
 </term><listitem><para>&#x007C; Single line vertical bar (ordinary). Similar: double-line
 vertical bar <literal>\Vert</literal>. For such that, as in the definition of a 
 set, use <literal>\mid</literal> because it is a relation.  
 </para>
-<para>For absolute value you can use the <filename>mathtools</filename> package and add
-<literal>\DeclarePairedDelimiter\abs{\lvert}{\rvert}</literal> to your
-preamble. This gives you three command variants for single-line vertical
-bars that are correctly horizontally spaced: if in the document body you
-write the starred version <literal>$\abs*{\frac{22}{7}}$</literal> then the
-height of the vertical bars will match the height of the argument,
-whereas with <literal>\abs{\frac{22}{7}}</literal> the bars do not grow with
-the height of the argument but instead are the default height, and
-<literal>\abs[<replaceable>size command</replaceable>]{\frac{22}{7}}</literal> also gives bars
-that do not grow but are set to the size given in the <replaceable>size
-command</replaceable>, e.g., <literal>\Bigg</literal>.
+<para>For absolute value you can use the <filename>mathtools</filename> package and in your
+preamble put
+<literal>\DeclarePairedDelimiter\abs{\lvert}{\rvert}</literal>. This gives you
+three command variants for single-line vertical bars that are correctly
+horizontally spaced: if in the document body you write the starred
+version <literal>$\abs*{\frac{22}{7}}$</literal> then the height of the
+vertical bars will match the height of the argument, whereas with
+<literal>\abs{\frac{22}{7}}</literal> the bars do not grow with the height of
+the argument but instead are the default height, and
+<literal>\abs[<replaceable>size command</replaceable>]{\frac{22}{7}}</literal> also gives bars that
+do not grow but are set to the size given in the <replaceable>size command</replaceable>,
+e.g., <literal>\Bigg</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\wedge</primary></indexterm><literal>\wedge</literal>
 </term><listitem><para>&#x2227; Logical and (binary).  Synonym: <literal>\land</literal>.  See also
@@ -8249,16 +10523,214 @@
 </term><listitem><para>&#x2240; Wreath product (binary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\Xi</primary></indexterm><literal>\Xi</literal>
-</term><listitem><para>&#x039E; Upper case Greek letter (ordinary).
+</term><listitem><para>&#x039E; uppercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\xi</primary></indexterm><literal>\xi</literal>
-</term><listitem><para>&#x03BE; Lower case Greek letter (ordinary).
+</term><listitem><para>&#x03BE; Lowercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\zeta</primary></indexterm><literal>\zeta</literal>
-</term><listitem><para>&#x03B6; Lower case Greek letter (ordinary).
+</term><listitem><para>&#x03B6; Lowercase Greek letter (ordinary).
 </para>
 </listitem></varlistentry></variablelist>
+<para>The following symbols are most often used in plain text but &latex;
+provides versions to use in mathematical text.
+</para>
+<variablelist><varlistentry><term><indexterm role="fn"><primary>\mathdollar</primary></indexterm><literal>\mathdollar</literal>
+</term><listitem><para>Dollar sign in math mode: $.
+</para>
+</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\mathparagraph</primary></indexterm><literal>\mathparagraph</literal>
+</term><listitem><para>Paragraph sign (pilcrow) in math mode, &#x00B6;.
+</para>
+</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\mathsection</primary></indexterm><literal>\mathsection</literal>
+</term><listitem><para>Section sign in math mode &#x00A7;.
+</para>
+</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\mathsterling</primary></indexterm><literal>\mathsterling</literal>
+</term><listitem><para>Sterling sign in math mode: £.
+</para>
+</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\mathunderscore</primary></indexterm><literal>\mathunderscore</literal>
+</term><listitem><para>Underscore in math mode: _.
+</para>
+</listitem></varlistentry></variablelist>
 
+
+<sect2 label="16.2.1" id="Blackboard-bold">
+<title>Blackboard bold</title>
+
+<indexterm role="cp"><primary>blackboard bold</primary></indexterm>
+<indexterm role="cp"><primary>doublestruck</primary></indexterm>
+
+<para>Synopsis:
+</para>
+<screen>\usepackage{amssymb}   % in preamble
+  ... 
+\mathbb{<replaceable>uppercase-letter</replaceable>}
+</screen>
+<para>Provide blackboard bold symbols, sometimes also known as doublestruck
+letters, used to denote number sets such as the natural numbers, the
+integers, etc.
+</para>
+<para>Here 
+</para>
+<screen>\( \forall n \in \mathbb{N}, n^2 \geq 0 \)
+</screen>
+<para>the <literal>\mathbb{N}</literal> gives blackboard bold symbol &#x2115;
+representing the natural numbers.
+</para>
+<para>If you use other than an uppercase letter then you do not get an error
+but you get strange results, including unexpected characters.
+</para>
+<para>There are packages that give access to symbols other than just the
+capital letters; look on CTAN.
+</para>
+
+</sect2>
+<sect2 label="16.2.2" id="Calligraphic">
+<title>Calligraphic</title>
+
+<indexterm role="cp"><primary>calligraphic fonts</primary></indexterm>
+<indexterm role="cp"><primary>script fonts</primary></indexterm>
+<indexterm role="cp"><primary>fonts, script</primary></indexterm>
+
+<para>Synopsis:
+</para>
+<screen>\mathcal{<replaceable>uppercase-letters</replaceable>}
+</screen>
+<para>Use a script-like font.
+</para>
+<para>In this example the graph identifier is output in a cursive font.
+</para>
+<screen>Let the graph be \( \mathcal{G} \).
+</screen>
+<para>If you use something other than an uppercase letter then you do not get
+an error.  Instead you get unexpected output.  For instance,
+<literal>\mathcal{g}</literal> outputs a close curly brace symbol, while
+<literal>\mathcal{+}</literal> outputs a plus sign.  
+</para>
+
+</sect2>
+<sect2 label="16.2.3" id="_005cboldmath-_0026-_005cunboldmath">
+<title><literal>\boldmath</literal> & <literal>\unboldmath</literal></title>
+
+<indexterm role="cp"><primary>boldface mathematics</primary></indexterm>
+<indexterm role="cp"><primary>symbols, boldface</primary></indexterm>
+<indexterm role="fn"><primary>\boldmath</primary></indexterm>
+<indexterm role="fn"><primary>\unboldmath</primary></indexterm>
+
+<para>Synopsis (used in paragraph mode or LR mode):
+</para>
+<screen>\boldmath \( <replaceable>math</replaceable> \)
+</screen>
+<para>or
+</para>
+<screen>\unboldmath \( <replaceable>math</replaceable> \)
+</screen>
+<indexterm role="fn"><primary>\boldmath</primary></indexterm>
+<indexterm role="fn"><primary>\unboldmath</primary></indexterm>
+<para>Declarations to change the letters and symbols in <replaceable>math</replaceable> to be in
+a bold font, or to countermand that and bring back the regular
+(non-bold) default. They must be used when not in math mode or display
+math mode (see <link linkend="Modes">Modes</link>). Both commands are fragile
+(see <link linkend="_005cprotect">\protect</link>).
+</para>
+<para>In this example each <literal>\boldmath</literal> command takes place inside an
+<literal>\mbox</literal>,
+</para>
+<screen>we have $\mbox{\boldmath \( v \)} = 5\cdot\mbox{\boldmath \( u \)$}$
+</screen>
+<para>which means <literal>\boldmath</literal> is only called in a text mode, here LR
+mode, and explains why &latex; must switch to math mode to set <literal>v</literal>
+and <literal>u</literal>.
+</para>
+<para>If you use either command inside math mode, as with <literal>Trouble: \(
+\boldmath x \)</literal>, then you get something like ‘<literal>LaTeX Font Warning:
+Command \boldmath invalid in math mode on input line 11</literal>’ and ‘<literal>LaTeX
+Font Warning: Command \mathversion invalid in math mode on input line
+11</literal>’.
+</para>
+<indexterm role="cp"><primary>package, <literal>bm</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>bm</literal> package</primary></indexterm>
+
+<para>There are many issues with <literal>\boldmath</literal>.  New documents should use
+the <filename>bm</filename> package provided by the &latex; Project team.  A complete
+description is outside the scope of this document (see the full
+documentation on CTAN) but even this small example
+</para>
+<screen>\usepackage{bm}   % in preamble
+...
+we have $\bm{v} = 5\cdot\bm{u}$
+</screen>
+<para>shows that it is an improvement over <literal>\boldmath</literal>.
+</para>
+
+</sect2>
+<sect2 label="16.2.4" id="Dots">
+<title>Dots, horizontal or vertical</title>
+
+<indexterm role="cp"><primary>ellipses</primary></indexterm>
+<indexterm role="cp"><primary>dots</primary></indexterm>
+
+<para>Ellipses are the three dots (usually three) indicating that a pattern
+continues.
+</para>
+<screen>\begin{array}{cccc}
+  a_{0,0}    &a_{0,1}   &a_{0,2} &\ldots \\
+  a_{1,0}    &\ddots                     \\
+  \vdots
+\end{array}
+</screen>
+<para>&latex; provides these.
+</para>
+<variablelist><anchor id="ellipses-cdots"/><varlistentry><term><indexterm role="fn"><primary>\cdots</primary></indexterm><literal>\cdots</literal>
+</term><listitem><para>Horizontal ellipsis with the dots raised to the center of the line, as
+in &#x22EF;.  Used as: <literal>\( a_0\cdot a_1\cdots a_{n-1}
+\)</literal>.
+</para>
+<anchor id="ellipses-ddots"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\ddots</primary></indexterm><literal>\ddots</literal>
+</term><listitem><para>Diagonal ellipsis, &#x22F1;.  See the above array example for a
+usage.
+</para>
+<anchor id="ellipses-ldots"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\ldots</primary></indexterm><literal>\ldots</literal>
+</term><listitem><para>Ellipsis on the baseline, &#x2026;.  Used as: <literal>\(
+x_0,\ldots x_{n-1} \)</literal>.  Another example is the above array example. A
+synonym is <literal>\mathellipsis</literal>.  A synonym from the <filename>amsmath</filename>
+package is <literal>\hdots</literal>.
+</para>
+<para>You can also use this command outside of mathematical text, as in
+<literal>The gears, brakes, \ldots{} are all broken</literal>.  (In a paragraph
+mode or LR mode a synonym for <literal>\ldots</literal> is <literal>\dots</literal>.)
+</para>
+<anchor id="ellipses-vdots"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\vdots</primary></indexterm><literal>\vdots</literal>
+</term><listitem><para>Vertical ellipsis, &#x22EE;.  See the above array example for a
+usage.
+</para>
+</listitem></varlistentry></variablelist>
+<indexterm role="cp"><primary>package, <literal>amsmath</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>amsmath</literal> package</primary></indexterm>
+
+<para>The <filename>amsmath</filename> package has the command <literal>\dots</literal> to semantically
+mark up ellipses.  This example produces two different-looking outputs
+for the first two uses of the <literal>\dots</literal> command.
+</para>
+<screen>\usepackage{amsmath}  % in preamble
+  ...
+Suppose that \( p_0, p_1, \dots, p_{n-1} \) lists all of the primes.
+Observe that \( p_0\cdot p_1 \dots \cdot p_{n-1} +1 \) is not a
+  multiple of any \( p_i \).
+Conclusion: there are infinitely many primes \( p_0, p_1, \dotsc \).
+</screen>
+<para>In the first line &latex; looks to the comma following <literal>\dots</literal> to
+determine that it should output an ellipsis on the baseline.  The second
+line has a <literal>\cdot</literal> following <literal>\dots</literal> so &latex; outputs an
+ellipsis that is on the math axis, vertically centered.  However, the
+third usage has no follow-on character so you have to tell &latex; what
+to do.  You can use one of the commands: <literal>\dotsc</literal> if you need the
+ellipsis appropriate for a comma following, <literal>\dotsb</literal> if you need
+the ellipses that fits when the dots are followed by a binary operator
+or relation symbol, <literal>\dotsi</literal> for dots with integrals, or
+<literal>\dotso</literal> for others.
+</para>
+
+</sect2>
 </sect1>
 <sect1 label="16.3" id="Math-functions">
 <title>Math functions</title>
@@ -8270,112 +10742,123 @@
 spacing.
 </para>
 <variablelist><varlistentry><term><indexterm role="fn"><primary>\arccos</primary></indexterm><literal>\arccos</literal>
-</term><listitem><para><inlineequation><mathphrase>\arccos</mathphrase></inlineequation>
+</term><listitem><para>Inverse cosine
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\arcsin</primary></indexterm><literal>\arcsin</literal>
-</term><listitem><para><inlineequation><mathphrase>\arcsin</mathphrase></inlineequation>
+</term><listitem><para>Inverse sine
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\arctan</primary></indexterm><literal>\arctan</literal>
-</term><listitem><para><inlineequation><mathphrase>\arctan</mathphrase></inlineequation>
+</term><listitem><para>Inverse tangent
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\arg</primary></indexterm><literal>\arg</literal>
-</term><listitem><para><inlineequation><mathphrase>\arg</mathphrase></inlineequation>
+</term><listitem><para>Angle between the real axis and a point in the complex plane
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\bmod</primary></indexterm><literal>\bmod</literal>
-</term><listitem><para>Binary modulo operator (<inlineequation><mathphrase>x \bmod y</mathphrase></inlineequation>)
+</term><listitem><para>Binary modulo operator, used as in <literal>\( 5\bmod 3=2 \)</literal>
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\cos</primary></indexterm><literal>\cos</literal>
-</term><listitem><para><inlineequation><mathphrase>\cos</mathphrase></inlineequation>
+</term><listitem><para>Cosine
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\cosh</primary></indexterm><literal>\cosh</literal>
-</term><listitem><para><inlineequation><mathphrase>\cosh</mathphrase></inlineequation>
+</term><listitem><para>Hyperbolic cosine
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\cot</primary></indexterm><literal>\cot</literal>
-</term><listitem><para><inlineequation><mathphrase>\cot</mathphrase></inlineequation>
+</term><listitem><para>Cotangent
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\coth</primary></indexterm><literal>\coth</literal>
-</term><listitem><para><inlineequation><mathphrase>\coth</mathphrase></inlineequation>
+</term><listitem><para>Hyperbolic cotangent
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\csc</primary></indexterm><literal>\csc</literal>
-</term><listitem><para><inlineequation><mathphrase>\csc</mathphrase></inlineequation>
+</term><listitem><para>Cosecant
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\deg</primary></indexterm><literal>\deg</literal>
-</term><listitem><para><inlineequation><mathphrase>\deg</mathphrase></inlineequation>
+</term><listitem><para>Degrees
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\det</primary></indexterm><literal>\det</literal>
-</term><listitem><para><inlineequation><mathphrase>\det</mathphrase></inlineequation>
+</term><listitem><para>Determinant
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\dim</primary></indexterm><literal>\dim</literal>
-</term><listitem><para><inlineequation><mathphrase>\dim</mathphrase></inlineequation>
+</term><listitem><para>Dimension
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\exp</primary></indexterm><literal>\exp</literal>
-</term><listitem><para><inlineequation><mathphrase>\exp</mathphrase></inlineequation>
+</term><listitem><para>Exponential
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\gcd</primary></indexterm><literal>\gcd</literal>
-</term><listitem><para><inlineequation><mathphrase>\gcd</mathphrase></inlineequation>
+</term><listitem><para>Greatest common divisor
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\hom</primary></indexterm><literal>\hom</literal>
-</term><listitem><para><inlineequation><mathphrase>\hom</mathphrase></inlineequation>
+</term><listitem><para>Homomorphism
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\inf</primary></indexterm><literal>\inf</literal>
-</term><listitem><para><inlineequation><mathphrase>\inf</mathphrase></inlineequation>
+</term><listitem><para>Infinum
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\ker</primary></indexterm><literal>\ker</literal>
-</term><listitem><para><inlineequation><mathphrase>\ker</mathphrase></inlineequation>
+</term><listitem><para>Kernel
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\lg</primary></indexterm><literal>\lg</literal>
-</term><listitem><para><inlineequation><mathphrase>\lg</mathphrase></inlineequation>
+</term><listitem><para>Base 2 logarithm
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\lim</primary></indexterm><literal>\lim</literal>
-</term><listitem><para><inlineequation><mathphrase>\lim</mathphrase></inlineequation>
+</term><listitem><para>Limit
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\liminf</primary></indexterm><literal>\liminf</literal>
-</term><listitem><para><inlineequation><mathphrase>\liminf</mathphrase></inlineequation>
+</term><listitem><para>Limit inferior
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\limsup</primary></indexterm><literal>\limsup</literal>
-</term><listitem><para><inlineequation><mathphrase>\limsup</mathphrase></inlineequation>
+</term><listitem><para>Limit superior
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\ln</primary></indexterm><literal>\ln</literal>
-</term><listitem><para><inlineequation><mathphrase>\ln</mathphrase></inlineequation>
+</term><listitem><para>Natural logarithm
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\log</primary></indexterm><literal>\log</literal>
-</term><listitem><para><inlineequation><mathphrase>\log</mathphrase></inlineequation>
+</term><listitem><para>Logarithm
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\max</primary></indexterm><literal>\max</literal>
-</term><listitem><para><inlineequation><mathphrase>\max</mathphrase></inlineequation>
+</term><listitem><para>Maximum
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\min</primary></indexterm><literal>\min</literal>
-</term><listitem><para><inlineequation><mathphrase>\min</mathphrase></inlineequation>
+</term><listitem><para>Minimum
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\pmod</primary></indexterm><literal>\pmod</literal>
-</term><listitem><para>parenthesized modulus, as in (<inlineequation><mathphrase>\pmod 2^n - 1</mathphrase></inlineequation>)
+</term><listitem><para>Parenthesized modulus, as used in <literal>\( 5\equiv 2\pmod 3 \)</literal>
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\Pr</primary></indexterm><literal>\Pr</literal>
-</term><listitem><para><inlineequation><mathphrase>\Pr</mathphrase></inlineequation>
+</term><listitem><para>Probability
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\sec</primary></indexterm><literal>\sec</literal>
-</term><listitem><para><inlineequation><mathphrase>\sec</mathphrase></inlineequation>
+</term><listitem><para>Secant
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\sin</primary></indexterm><literal>\sin</literal>
-</term><listitem><para><inlineequation><mathphrase>\sin</mathphrase></inlineequation>
+</term><listitem><para>Sine
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\sinh</primary></indexterm><literal>\sinh</literal>
-</term><listitem><para><inlineequation><mathphrase>\sinh</mathphrase></inlineequation>
+</term><listitem><para>Hyperbolic sine
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\sup</primary></indexterm><literal>\sup</literal>
-</term><listitem><para><inlineequation><mathphrase>\sup</mathphrase></inlineequation>
+</term><listitem><para>sup
 <!-- don't try to use \sup with dvi/pdf output since that turned into a -->
 <!-- Texinfo command and it's not worth hassling with different versions -->
 <!-- when it's just three roman letters anyway. -->
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\tan</primary></indexterm><literal>\tan</literal>
-</term><listitem><para><inlineequation><mathphrase>\tan</mathphrase></inlineequation>
+</term><listitem><para>Tangent
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\tanh</primary></indexterm><literal>\tanh</literal>
-</term><listitem><para><inlineequation><mathphrase>\tanh</mathphrase></inlineequation>
+</term><listitem><para>Hyperbolic tangent
 </para>
 </listitem></varlistentry></variablelist>
+<indexterm role="cp"><primary>package, <literal>amsmath</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>amsmath</literal> package</primary></indexterm>
 
+<para>The <filename>amsmath</filename> package adds improvements on some of these, and also
+allows you to define your own.  The full documentation is on CTAN, but
+briefly, you can define an identity operator with
+<literal>\DeclareMathOperator{\identity}{id}</literal> that is like the ones
+above but prints as ‘<literal>id</literal>’.  The starred form
+<literal>\DeclareMathOperator*{\op}{op}</literal> sets any limits above and
+below, as is traditional with <literal>\lim</literal>, <literal>\sup</literal>, or <literal>\max</literal>.
+</para>
+
 </sect1>
 <sect1 label="16.4" id="Math-accents">
 <title>Math accents</title>
@@ -8389,277 +10872,438 @@
 </para>
 <variablelist><varlistentry><term><indexterm role="fn"><primary>\acute</primary></indexterm><literal>\acute</literal>
 </term><listitem><indexterm role="cp"><primary>acute accent, math</primary></indexterm>
-<para>Math acute accent: <inlineequation><mathphrase>\acute{x}</mathphrase></inlineequation>.
+<para>Math acute accent
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\bar</primary></indexterm><literal>\bar</literal>
 </term><listitem><indexterm role="cp"><primary>bar-over accent, math</primary></indexterm>
 <indexterm role="cp"><primary>macron accent, math</primary></indexterm>
-<para>Math bar-over accent: <inlineequation><mathphrase>\bar{x}</mathphrase></inlineequation>.
+<para>Math bar-over accent
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\breve</primary></indexterm><literal>\breve</literal>
 </term><listitem><indexterm role="cp"><primary>breve accent, math</primary></indexterm>
-<para>Math breve accent: <inlineequation><mathphrase>\breve{x}</mathphrase></inlineequation>.
+<para>Math breve accent
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\check</primary></indexterm><literal>\check</literal>
 </term><listitem><indexterm role="cp"><primary>check accent, math</primary></indexterm>
 <indexterm role="cp"><primary>háček accent, math</primary></indexterm>
-<para>Math háček (check) accent: <inlineequation><mathphrase>\check{x}</mathphrase></inlineequation>.
+<para>Math háček (check) accent
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\ddot</primary></indexterm><literal>\ddot</literal>
 </term><listitem><indexterm role="cp"><primary>double dot accent, math</primary></indexterm>
-<para>Math dieresis accent: <inlineequation><mathphrase>\ddot{x}</mathphrase></inlineequation>.
+<para>Math dieresis accent
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\dot</primary></indexterm><literal>\dot</literal>
 </term><listitem><indexterm role="cp"><primary>overdot accent, math</primary></indexterm>
 <indexterm role="cp"><primary>dot over accent, math</primary></indexterm>
-<para>Math dot accent: <inlineequation><mathphrase>\dot{x}</mathphrase></inlineequation>.
+<para>Math dot accent
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\grave</primary></indexterm><literal>\grave</literal>
 </term><listitem><indexterm role="cp"><primary>grave accent, math</primary></indexterm>
-<para>Math grave accent: <inlineequation><mathphrase>\grave{x}</mathphrase></inlineequation>.
+<para>Math grave accent
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\hat</primary></indexterm><literal>\hat</literal>
 </term><listitem><indexterm role="cp"><primary>hat accent, math</primary></indexterm>
 <indexterm role="cp"><primary>circumflex accent, math</primary></indexterm>
-<para>Math hat (circumflex) accent: <inlineequation><mathphrase>\hat{x}</mathphrase></inlineequation>.
+<para>Math hat (circumflex) accent
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\imath</primary></indexterm><literal>\imath</literal>
-</term><listitem><indexterm role="cp"><primary>dotless i, math</primary></indexterm>
-<para>Math dotless i.
-</para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\jmath</primary></indexterm><literal>\jmath</literal>
-</term><listitem><indexterm role="cp"><primary>dotless j, math</primary></indexterm>
-<para>Math dotless j.
-</para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\mathring</primary></indexterm><literal>\mathring</literal>
 </term><listitem><indexterm role="cp"><primary>ring accent, math</primary></indexterm>
-<para>Math ring accent: x*.  <!-- don't bother implementing in texinfo -->
+<para>Math ring accent  <!-- don't bother implementing in texinfo -->
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\tilde</primary></indexterm><literal>\tilde</literal>
 </term><listitem><indexterm role="cp"><primary>tilde accent, math</primary></indexterm>
-<para>Math tilde accent: <inlineequation><mathphrase>\tilde{x}</mathphrase></inlineequation>.
+<para>Math tilde accent
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\vec</primary></indexterm><literal>\vec</literal>
 </term><listitem><indexterm role="cp"><primary>vector symbol, math</primary></indexterm>
-<para>Math vector symbol: <inlineequation><mathphrase>\vec{x}</mathphrase></inlineequation>.
+<para>Math vector symbol
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\widehat</primary></indexterm><literal>\widehat</literal>
 </term><listitem><indexterm role="cp"><primary>wide hat accent, math</primary></indexterm>
-<para>Math wide hat accent: <inlineequation><mathphrase>\widehat{x+y}</mathphrase></inlineequation>.
+<para>Math wide hat accent
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\widetilde</primary></indexterm><literal>\widetilde</literal>
 </term><listitem><indexterm role="cp"><primary>wide tilde accent, math</primary></indexterm>
-<para>Math wide tilde accent: <inlineequation><mathphrase>\widetilde{x+y}</mathphrase></inlineequation>.
+<para>Math wide tilde accent
 </para>
 </listitem></varlistentry></variablelist>
+<para>When you are putting an accent on an i or a j, the tradition is to use
+one without a dot, <literal>\imath</literal> or <literal>jmath</literal> (see <link linkend="Math-symbols">Math symbols</link>).
+</para>
 
 </sect1>
-<sect1 label="16.5" id="Spacing-in-math-mode">
+<sect1 label="16.5" id="Over_002d-and-Underlining">
+<title>Over- and Underlining</title>
+
+<indexterm role="cp"><primary>overlining</primary></indexterm>
+<indexterm role="cp"><primary>underlining</primary></indexterm>
+
+<para>&latex; provides commands for making overlines or underlines, or
+putting braces over or under some material.
+</para>
+<variablelist>
+<varlistentry><term><indexterm role="fn"><primary>\underline{<replaceable>text</replaceable>}</primary></indexterm><literal>\underline{<replaceable>text</replaceable>}</literal>
+</term><listitem><para>Underline <replaceable>text</replaceable>.  Works inside math mode, and outside.
+The line is always completely below the text, taking account of
+descenders, so in <literal>\(\underline{y}\)</literal> the line is lower than in
+<literal>\(\underline{x}\)</literal>.  This command is fragile (see <link linkend="_005cprotect">\protect</link>).
+</para>
+<indexterm role="cp"><primary>package, <literal>ulem</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>ulem</literal> package</primary></indexterm>
+
+<para>Note that the package <filename>ulem</filename> does text mode underlining and allows
+line breaking as well as a number of other features.  See the
+documentation on CTAN.  See also <link linkend="_005chrulefill-_0026-_005cdotfill">\hrulefill & \dotfill</link> for
+producing a line, for such things as a signature.
+</para>        
+</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\overline{<replaceable>text</replaceable>}</primary></indexterm><literal>\overline{<replaceable>text</replaceable>}</literal>
+</term><listitem><para>Put a horizontal line over <replaceable>text</replaceable>.  Works inside math mode, and
+outside.  For example, <literal>\overline{x+y}</literal>.
+Note that this differs from the command <literal>\bar</literal> (see <link linkend="Math-accents">Math
+accents</link>).
+</para>
+</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\underbrace{<replaceable>math</replaceable>}</primary></indexterm><literal>\underbrace{<replaceable>math</replaceable>}</literal>
+</term><listitem><para>Put a brace under <replaceable>math</replaceable>. For example, this
+<literal>(1-\underbrace{1/2)+(1/2}-1/3)</literal> emphasizes the telescoping part.
+Attach text to the brace by using subscript, <literal>_</literal>, or superscript,
+<literal>^</literal>, as here.
+</para>
+<screen>\begin{displaymath}
+  1+1/2+\underbrace{1/3+1/4}_{>1/2}+
+       \underbrace{1/5+1/6+1/7+1/8}_{>1/2}+\cdots
+\end{displaymath}
+</screen>
+<para>The superscript appears on top of the expression, and so can look
+unconnected to the underbrace.
+</para>
+</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\overbrace{<replaceable>math</replaceable>}</primary></indexterm><literal>\overbrace{<replaceable>math</replaceable>}</literal>
+</term><listitem><para>Put a brace over <replaceable>math</replaceable>, as with
+<literal>\overbrace{x+x+\cdots+x}^{\mbox{\(k\) times}}</literal>.  See also
+<literal>\underbrace</literal>.
+</para>
+</listitem></varlistentry></variablelist>
+<indexterm role="cp"><primary>package, <literal>mathtools</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>mathtools</literal> package</primary></indexterm>
+
+<para>The package <filename>mathtools</filename> adds an over- and underbrace, as well as
+some improvements on the braces.  See the documentation on CTAN.
+</para>
+
+</sect1>
+<sect1 label="16.6" id="Spacing-in-math-mode">
 <title>Spacing in math mode</title>
 
 <indexterm role="cp"><primary>spacing within math mode</primary></indexterm>
 <indexterm role="cp"><primary>math mode, spacing</primary></indexterm>
 
-<para>In a <literal>math</literal> environment, &latex; ignores the spaces that you use
-in the source, and instead puts in the spacing according to the normal
-rules for mathematics texts.  
+<para>When typesetting mathematics, &latex; puts in spacing according to the
+normal rules for mathematics texts.  If you enter <literal>y=m x</literal> then
+&latex; ignores the space and in the output the m is next to the x,
+as <inlineequation><mathphrase>y=mx</mathphrase></inlineequation>.
 </para>
-<para>Many math mode spacing definitions are expressed in terms of the math unit
-<firstterm>mu</firstterm> given by 1 em = 18 mu, where the em is taken from the current
-math symbols family (see <link linkend="Units-of-length">Units of length</link>).
-&latex; provides the following commands for use in math mode:
+<para>But &latex;’s rules sometimes need tweaking.  For example, in an
+integral the tradition is to put a small extra space between the
+<literal>f(x)</literal> and the <literal>dx</literal>, here done with the <literal>\,</literal> command.
 </para>
+<screen>\int_0^1 f(x)\,dx
+</screen>
+<para>&latex; provides the commands that follow for use in math mode.  Many
+of these spacing definitions are expressed in terms of the math unit
+<firstterm>mu</firstterm>.  It is defined as 1/18em, where the em is taken from the
+current math symbols family (see <link linkend="Units-of-length">Units of length</link>).  Thus, a
+<literal>\thickspace</literal> is something like 5/18 times the width of
+a ‘<literal>M</literal>’.
+</para>
 <variablelist><varlistentry><term><literal>\;</literal>
 </term><listitem><indexterm role="fn"><primary>\;</primary></indexterm>
 <indexterm role="fn"><primary>\thickspace</primary></indexterm>
-<para>Normally <literal>5.0mu plus 5.0mu</literal>.  The longer name is
-<literal>\thickspace</literal>.  Math mode only.
+<anchor id="spacing-in-math-mode-thickspace"/><para>Synonym: <literal>\thickspace</literal>.  Normally <literal>5.0mu plus 5.0mu</literal>.  Math
+mode only.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>\:</literal>
 </term><term><literal>\></literal>
 </term><listitem><indexterm role="fn"><primary>\:</primary></indexterm>
 <indexterm role="fn"><primary>\></primary></indexterm>
 <indexterm role="fn"><primary>\medspace</primary></indexterm>
-<para>Normally <literal>4.0mu plus 2.0mu minus 4.0mu</literal>.  The longer name is
-<literal>\medspace</literal>.  Math mode only.
+<anchor id="spacing-in-math-mode-medspace"/><para>Synonym: <literal>\medspace</literal>.  Normally <literal>4.0mu plus 2.0mu minus 4.0mu</literal>.
+Math mode only.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>\,</literal>
 </term><listitem><indexterm role="fn"><primary>\,</primary></indexterm>
 <indexterm role="fn"><primary>\thinspace</primary></indexterm>
-<para>Normally <literal>3mu</literal>.  The longer name is <literal>\thinspace</literal>.  This can
-be used in both math mode and text mode. See <link linkend="_005cthinspace">\thinspace</link>.
+<indexterm role="cp"><primary>thin space</primary></indexterm>
+<anchor id="Spacing-in-math-mode_002f_005cthinspace"/><anchor id="spacing-in-math-mode-thinspace"/><para>Synonym: <literal>\thinspace</literal>.  Normally <literal>3mu</literal>, which is 1/6em.
+Can be used in both math mode and text mode (see <link linkend="_005cthinspace-_0026-_005cnegthinspace">\thinspace &
+\negthinspace</link>).
 </para>
+<para>This space is widely used, for instance between the function and the
+infinitesimal in an integral <literal>\int f(x)\,dx</literal> and, if an author does
+this, before punctuation in a displayed equation.
+</para>
+<screen>The antiderivative is
+\begin{equation}
+  3x^{-1/2}+3^{1/2}\,.
+\end{equation}
+</screen>
 </listitem></varlistentry><varlistentry><term><literal>\!</literal>
 </term><listitem><indexterm role="fn"><primary>\!</primary></indexterm>
-<para>A negative thin space. Normally <literal>-3mu</literal>.  Math mode only.
+<indexterm role="fn"><primary>\negthinspace</primary></indexterm>
+<indexterm role="cp"><primary>thin space, negative</primary></indexterm>
+<anchor id="spacing-in-math-mode-negthinspace"/><para>A negative thin space. Normally <literal>-3mu</literal>.  The <literal>\!</literal> command is
+math mode only but the <literal>\negthinspace</literal> command is available for
+text mode (see <link linkend="_005cthinspace-_0026-_005cnegthinspace">\thinspace & \negthinspace</link>).
 </para>
 </listitem></varlistentry><varlistentry><term><literal>\quad</literal>
 </term><listitem><indexterm role="cp"><primary>quad</primary></indexterm>
 <indexterm role="fn"><primary>\quad</primary></indexterm>
-<para>This is 18mu, that is, 1em. This is often used for space
+<anchor id="spacing-in-math-mode-quad"/><para>This is 18mu, that is, 1em. This is often used for space
 surrounding equations or expressions, for instance for the space between
 two equations inside a <literal>displaymath</literal> environment.  It is available
 in both text and math mode.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>\qquad</literal>
 </term><listitem><indexterm role="fn"><primary>\qquad</primary></indexterm>
-<para>A length of 2 quads, that is, 36mu = 2em.  It is available in
+<anchor id="spacing-in-math-mode-qquad"/><para>A length of 2 quads, that is, 36mu = 2em.  It is available in
 both text and math mode.
 </para></listitem></varlistentry></variablelist>
-<para>In this example a thinspace separates the function from the
-infinitesimal.
-</para>
-<screen>\int_0^1 f(x)\,dx
-</screen>
 
 </sect1>
-<sect1 label="16.6" id="Math-miscellany">
+<sect1 label="16.7" id="Math-miscellany">
 <title>Math miscellany</title>
 
 <indexterm role="cp"><primary>math miscellany</primary></indexterm>
 
-<variablelist><varlistentry><term><indexterm role="fn"><primary>\*</primary></indexterm><literal>\*</literal>
-</term><listitem><indexterm role="cp"><primary>discretionary multiplication</primary></indexterm>
-<indexterm role="cp"><primary>multiplication symbol, discretionary line break</primary></indexterm>
-<para>A <firstterm>discretionary</firstterm> multiplication symbol, at which a line break is
-allowed. Without the break multiplication is implicitly indicated by a
-space, while in the case of a break a &#x00D7; symbol is
-printed immediately before the break. So
+<para>&latex; contains a wide variety of mathematics facilities.  Here are
+some that don’t fit into other categories.
 </para>
-<screen>\documentclass{article}
-\begin{document}
-Now \(A_3 = 0\), hence the product of all terms \(A_1\) 
-through \(A_4\), that is \(A_1\* A_2\* A_3 \* A_4\), is 
-equal to zero.
-\end{document}
+
+
+<sect2 label="16.7.1" id="Colon-character-_0026-_005ccolon">
+<title>Colon character <literal>:</literal> & <literal>\colon</literal></title>
+
+<indexterm role="cp"><primary>:</primary></indexterm>
+<indexterm role="cp"><primary>colon character</primary></indexterm>
+<indexterm role="fn"><primary>:</primary></indexterm>
+<indexterm role="fn"><primary>\colon</primary></indexterm>
+
+<para>Synopsis, one of:
+</para>
+<screen>:
+\colon
 </screen>
-<para>will make that sort of output<!-- -->
- <!-- /@w -->(the ellipsis ‘<literal>[…]</literal>’ is here to show the line break at
-the same place as in a &tex; output)<!-- -->
-:
+<para>In mathematics, the colon character, <literal>:</literal>, is a relation.
 </para>
-<para>Now <inlineequation><mathphrase>A_3 = 0</mathphrase></inlineequation>,
-[…]
-<inlineequation><mathphrase>A_1</mathphrase></inlineequation>
-through <inlineequation><mathphrase>A_4</mathphrase></inlineequation>, that is <inlineequation><mathphrase>A_1 A_2 \times</mathphrase></inlineequation>
-<inlineequation><mathphrase>A_3 A_4</mathphrase></inlineequation>, is
-equal to zero.
+<screen>With side ratios \( 3:4 \) and \( 4:5 \), the triangle is right.
+</screen>
+<indexterm role="cp"><primary>package, <literal>amsmath</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>amsmath</literal> package</primary></indexterm>
+
+<para>Ordinary &latex; defines <literal>\colon</literal> to produce the colon character
+with the spacing appropriate for punctuation, as in set-builder notation
+<literal>\{x\colon 0\leq x<1\}</literal>.
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\cdots</primary></indexterm><literal>\cdots</literal>
-</term><listitem><para>A horizontal ellipsis with the dots raised to the center of the line.
+<indexterm role="cp"><primary>package, <literal>amsmath</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>amsmath</literal> package</primary></indexterm>
+
+<para>But the widely-used <filename>amsmath</filename> package defines <literal>\colon</literal> for use
+in the definition of functions <literal>f\colon D\to C</literal>.  So if you want
+the colon character as a punctuation then use <literal>\mathpunct{:}</literal>.
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\ddots</primary></indexterm><literal>\ddots</literal>
-</term><listitem><para>A diagonal ellipsis: <inlineequation><mathphrase>\ddots</mathphrase></inlineequation>.
+
+</sect2>
+<sect2 label="16.7.2" id="_005c_002a">
+<title><literal>\*</literal></title>
+
+<indexterm role="cp"><primary>multiplication, discretionary</primary></indexterm>
+<indexterm role="cp"><primary>breaks, multiplication discretionary</primary></indexterm>
+<indexterm role="cp"><primary>line breaks, multiplication discretionary</primary></indexterm>
+<indexterm role="cp"><primary>discretionary breaks, multiplication</primary></indexterm>
+<indexterm role="fn"><primary>\*</primary></indexterm>
+
+<para>Synopsis:
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\frac{<replaceable>num</replaceable>}{<replaceable>den</replaceable>}</primary></indexterm><literal>\frac{<replaceable>num</replaceable>}{<replaceable>den</replaceable>}</literal>
-</term><listitem><indexterm role="fn"><primary>\frac</primary></indexterm>
-<para>Produces the fraction <replaceable>num</replaceable> divided by <replaceable>den</replaceable>.
+<screen>\*
+</screen>
+<para>A multiplication symbol that allows a line break.  If there is a break
+then &latex; puts a <literal>\times</literal> symbol, &#x00D7;, before
+that break.
 </para>
+<para>In <literal>\( A_1\* A_2\* A_3\* A_4 \)</literal>, if there is no line break then
+&latex; outputs it as though it were <literal>\( A_1 A_2 A_3 A_4 \)</literal>.  If
+a line break does happen, for example between the two middle ones, then
+&latex; sets it like <literal>\( A_1 A_2 \times \)</literal>, followed by the
+break, followed by <literal>\( A_3 A_4 \)</literal>.
+</para>
 
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\left <replaceable>delim1</replaceable> ... \right <replaceable>delim2</replaceable></primary></indexterm><literal>\left <replaceable>delim1</replaceable> ... \right <replaceable>delim2</replaceable></literal>
-</term><listitem><indexterm role="fn"><primary>\right</primary></indexterm>
-<indexterm role="cp"><primary>null delimiter</primary></indexterm>
-<para>The two delimiters need not match; ‘<literal>.</literal>’ acts as a <firstterm>null delimiter</firstterm>,
-producing no output.  The delimiters are sized according to the math
-in between.  Example: <literal>\left( \sum_{i=1}^{10} a_i \right]</literal>.
+</sect2>
+<sect2 label="16.7.3" id="_005cfrac">
+<title><literal>\frac</literal></title>
+
+<indexterm role="cp"><primary>fraction</primary></indexterm>
+<indexterm role="fn"><primary>\frac</primary></indexterm>
+
+<para>Synopsis:
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\mathdollar</primary></indexterm><literal>\mathdollar</literal>
-</term><listitem><para>Dollar sign in math mode: $.
+<screen>\frac{<replaceable>numerator</replaceable>}{<replaceable>denominator</replaceable>}
+</screen>
+<para>Produces the fraction.  Used as: <literal>\begin{displaymath}
+\frac{1}{\sqrt{2\pi\sigma}} \end{displaymath}</literal>.  In inline math
+mode it comes out small; see the discussion of <literal>\displaystyle</literal>
+(see <link linkend="Math-formulas">Math formulas</link>).
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\mathellipsis</primary></indexterm><literal>\mathellipsis</literal>
-</term><listitem><para>Ellipsis (spaced for text) in math mode: ….
+
+</sect2>
+<sect2 label="16.7.4" id="_005cleft-_0026-_005cright">
+<title><literal>\left</literal> & <literal>\right</literal></title>
+
+<indexterm role="cp"><primary>delimiters, paired</primary></indexterm>
+<indexterm role="cp"><primary>paired delimiters</primary></indexterm>
+<indexterm role="cp"><primary>matching parentheses</primary></indexterm>
+<indexterm role="cp"><primary>matching brackets</primary></indexterm>
+<indexterm role="cp"><primary>null delimiter</primary></indexterm>
+<indexterm role="fn"><primary>\left</primary></indexterm>
+<indexterm role="fn"><primary>\right</primary></indexterm>
+
+<para>Synopsis:
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\mathparagraph</primary></indexterm><literal>\mathparagraph</literal>
-</term><listitem><para>Paragraph sign (pilcrow) in math mode: &#x00B6;.
+<screen>\left <replaceable>delimiter1</replaceable> ... \right <replaceable>delimiter2</replaceable>
+</screen>
+<para>Make matching parentheses, braces, or other delimiters.  The delimiters
+are sized according to the math they enclose.  This makes a unit vector
+surrounded by appropriate-height parentheses.
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\mathsection</primary></indexterm><literal>\mathsection</literal>
-</term><listitem><para>Section sign in math mode.
+<screen>\begin{equation}
+  \left(\begin{array}{c}
+    1   \\
+    0   \\
+  \end{array}\right)
+</screen>
+<para>Every <literal>\left</literal> must have a matching <literal>\right</literal>.  Leaving out the
+<literal>\left(</literal> in the above gets ‘<literal>Extra \right</literal>’.  Leaving off the
+<literal>\right)</literal> gets ‘<literal>You can't use `\eqno' in math mode</literal>’.
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\mathsterling</primary></indexterm><literal>\mathsterling</literal>
-</term><listitem><para>Sterling sign in math mode: £.
+<para>However, the two delimiters <replaceable>delimiter1</replaceable> and <replaceable>delimiter2</replaceable> need
+not match.  A common case is that you want an unmatched brace, as
+below. Use a period, ‘<literal>.</literal>’, as a null delimiter.
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\mathunderscore</primary></indexterm><literal>\mathunderscore</literal>
-</term><listitem><para>Underscore in math mode: _.
+<screen>\begin{equation}
+  f(n)=\left\{\begin{array}{ll}
+                1             &\mbox{--if \(n=0\)} \\
+                f(n-1)+3n^2   &\mbox{--else}       
+       \end{array}\right.
+\end{equation}
+</screen>
+<para>Note that to get a curly brace as a delimiter you must prefix it with a
+backslash, <literal>\{</literal>.
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\overbrace{<replaceable>math</replaceable>}</primary></indexterm><literal>\overbrace{<replaceable>math</replaceable>}</literal>
-</term><listitem><para>Generates a brace over <replaceable>math</replaceable>.
-For example, <literal>\overbrace{x+\cdots+x}^{k \;\textrm{times}}</literal>.
-</para>        
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\overline{<replaceable>text</replaceable>}</primary></indexterm><literal>\overline{<replaceable>text</replaceable>}</literal>
-</term><listitem><para>Generates a horizontal line over <replaceable>tex</replaceable>.
-For example, <literal>\overline{x+y}</literal>.
+
+</sect2>
+<sect2 label="16.7.5" id="_005csqrt">
+<title><literal>\sqrt</literal></title>
+
+<indexterm role="cp"><primary>square root</primary></indexterm>
+<indexterm role="cp"><primary>roots</primary></indexterm>
+<indexterm role="cp"><primary>radical</primary></indexterm>
+<indexterm role="fn"><primary>\sqrt</primary></indexterm>
+
+<para>Synopsis, one of:
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\sqrt[<replaceable>root</replaceable>]{<replaceable>arg</replaceable>}</primary></indexterm><literal>\sqrt[<replaceable>root</replaceable>]{<replaceable>arg</replaceable>}</literal>
-</term><listitem><para>Produces the representation of the square root of <replaceable>arg</replaceable>.  The
-optional argument <replaceable>root</replaceable> determines what root to produce.  For
-example, the cube root of <literal>x+y</literal> would be typed as
-<literal>\sqrt[3]{x+y}</literal>.
+<screen>\sqrt{<replaceable>arg</replaceable>}
+\sqrt[<replaceable>root-number</replaceable>]{<replaceable>arg</replaceable>}
+</screen>
+<para>The square root, or optionally other roots, of <replaceable>arg</replaceable>.  The optional
+argument <replaceable>root-number</replaceable> gives the root, i.e., enter the cube root of
+<literal>x+y</literal> as <literal>\sqrt[3]{x+y}</literal>.
+The radical grows with the size of <replaceable>arg</replaceable> (as the height of the
+radical grows, the angle on the leftmost part gets steeper, until for
+a large enough <literal>arg</literal>, it is vertical).
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\stackrel{<replaceable>text</replaceable>}{<replaceable>relation</replaceable>}</primary></indexterm><literal>\stackrel{<replaceable>text</replaceable>}{<replaceable>relation</replaceable>}</literal>
-</term><listitem><para>Puts <replaceable>text</replaceable> above <replaceable>relation</replaceable>.  For example,
-<literal>\stackrel{f}{\longrightarrow}</literal>.
+<para>&latex; has a separate <literal>\surd</literal> character (see <link linkend="Math-symbols">Math symbols</link>).
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\underbrace{<replaceable>math</replaceable>}</primary></indexterm><literal>\underbrace{<replaceable>math</replaceable>}</literal>
-</term><listitem><para>Generates <replaceable>math</replaceable> with a brace underneath. For example, <literal>\underbrace{x+y+z}_{>\,0}</literal>
+
+</sect2>
+<sect2 label="16.7.6" id="_005cstackrel">
+<title><literal>\stackrel</literal></title>
+
+<indexterm role="cp"><primary>stack math</primary></indexterm>
+<indexterm role="cp"><primary>relation, text above</primary></indexterm>
+<indexterm role="fn"><primary>\stackrel</primary></indexterm>
+
+<para>Synopsis, one of:
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\underline{<replaceable>text</replaceable>}</primary></indexterm><literal>\underline{<replaceable>text</replaceable>}</literal>
-</term><listitem><para>Causes <replaceable>text</replaceable>, which may be either math mode or not, to be
-underlined.  The line is always below the text, taking account of
-descenders.
+<screen>\stackrel{<replaceable>text</replaceable>}{<replaceable>relation</replaceable>}
+</screen>
+<para>Put <replaceable>text</replaceable> above <replaceable>relation</replaceable>.  To put a function name above an
+arrow enter <literal>\stackrel{f}{\longrightarrow}</literal>.
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\vdots</primary></indexterm><literal>\vdots</literal>
-</term><listitem><para>Produces a vertical ellipsis.
-</para>
-</listitem></varlistentry></variablelist>
 
+</sect2>
 </sect1>
 </chapter>
 <chapter label="17" id="Modes">
 <title>Modes</title>
 
 <indexterm role="cp"><primary>modes</primary></indexterm>
-<indexterm role="cp"><primary>paragraph mode</primary></indexterm>
-<indexterm role="cp"><primary>math mode</primary></indexterm>
+
+<para>As &latex; processes your document, at any point it is in one of six
+modes.  They fall into three categories of two each, the horizontal
+modes, the math modes, and the vertical modes. Some commands only work
+in one mode or another (in particular, many commands only work in one of
+the math modes), and error messages will refer to these.
+</para>
+<itemizedlist><listitem><anchor id="modes-paragraph-mode"/><indexterm role="cp"><primary>paragraph mode</primary></indexterm>
+<para><firstterm>Paragraph mode</firstterm> is what &latex; is in when processing ordinary
+text.  It breaks the input text into lines and breaks the lines into
+pages.  This is the mode &latex; is in most of the time.
+</para>
 <indexterm role="cp"><primary>left-to-right mode</primary></indexterm>
 <indexterm role="cp"><primary>LR mode</primary></indexterm>
-
-<para>When &latex; is processing your input text, it is always in one of three
-modes:
+<anchor id="modes-lr-mode"/><para><firstterm>LR mode</firstterm> (for left-to-right mode; in plain &tex; this is called
+<firstterm>restricted horizontal mode</firstterm>) is in effect when &latex; starts
+making a box with an <literal>\mbox</literal> command.  As in paragraph mode,
+&latex;’s output is a string of words with spaces between them.  Unlike
+in paragraph mode, in LR mode &latex; never starts a new line, it just
+keeps going from left to right.  (Although &latex; will not complain
+that the LR box is too long, when it is finished and next tries to put
+that box into a line, it could very well complain that the finished LR
+box won’t fit there.)
 </para>
-<itemizedlist><listitem><para>Paragraph mode
-</para></listitem><listitem><para>Math mode
-</para></listitem><listitem><para>Left-to-right mode, called LR mode for short
-</para></listitem></itemizedlist>
-<para>Mode changes occur only when entering or leaving an environment, or when
-&latex; is processing the argument of certain text-producing commands.
+</listitem><listitem><indexterm role="cp"><primary>math mode</primary></indexterm>
+<anchor id="modes-math-mode"/><para><firstterm>Math mode</firstterm> is when &latex; is generating
+an inline mathematical formula.
 </para>
-<para><firstterm>Paragraph mode</firstterm> is the most common; it’s the one &latex; is in
-when processing ordinary text.  In this mode, &latex; breaks the
-input text into lines and breaks the lines into pages.
+<indexterm role="cp"><primary>display math mode</primary></indexterm>
+<para><firstterm>Display math mode</firstterm> is when &latex; is generating a displayed
+mathematical formula.  (Displayed formulas differ somewhat from inline
+ones.  One example is that the placement of the subscript on <literal>\int</literal>
+differs in the two situations.)
 </para>
-<para>&latex; is in <firstterm>math mode</firstterm> when it’s generating a mathematical
-formula, either displayed math or within a line.
+</listitem><listitem><indexterm role="cp"><primary>vertical mode</primary></indexterm>
+<anchor id="modes-vertical-mode"/><para><firstterm>Vertical mode</firstterm> is when &latex; is building the list of lines and
+other material making the output page.  This is the mode &latex; is in
+when it starts a document.
 </para>
-<indexterm role="fn"><primary>\mbox, and LR mode</primary></indexterm>
-<para>In <firstterm>LR mode</firstterm>, as in paragraph mode, &latex; considers the output
-that it produces to be a string of words with spaces between them.
-However, unlike paragraph mode, &latex; keeps going from left to
-right; it never starts a new line in LR mode.  Even if you put a
-hundred words into an <literal>\mbox</literal>, &latex; would keep typesetting
-them from left to right inside a single box (and then most likely
-complain because the resulting box was too wide to fit on the line).
-&latex; is in LR mode when it starts making a box with an
-<literal>\mbox</literal> command.  You can get it to enter a different mode inside
-the box—for example, you can make it enter math mode to put a
-formula in the box.
+<indexterm role="cp"><primary>internal vertical mode</primary></indexterm>
+<anchor id="modes-internal-vertical-mode"/><para><firstterm>Internal vertical mode</firstterm> is in effect when &latex; starts making a
+<literal>\vbox</literal>.  This is the vertical analogue of LR mode.
 </para>
-<para>There are also several text-producing commands and environments for
-making a box that put &latex; into paragraph mode.  The box made by
-one of these commands or environments will be called a <literal>parbox</literal>.
-When &latex; is in paragraph mode while making a box, it is said to
-be in “inner paragraph mode” (no page breaks).  Its normal paragraph
-mode, which it starts out in, is called “outer paragraph mode”.
+</listitem></itemizedlist>
+<para>For instance, if you begin a &latex; article with ‘<literal>Let \( x \) be
+...</literal>’ then these are the modes: first &latex; starts every document in
+vertical mode, then it reads the ‘<literal>L</literal>’ and switches to paragraph
+mode, then the next switch happens at the ‘<literal>\(</literal>’ where &latex;
+changes to math mode, and then when it leaves the formula it pops
+back to paragraph mode.
 </para>
+<indexterm role="cp"><primary>inner paragraph mode</primary></indexterm>
+<indexterm role="cp"><primary>outer paragraph mode</primary></indexterm>
+<anchor id="modes-inner-paragraph-mode"/><anchor id="modes-outer-paragraph-mode"/><para>Paragraph mode has two subcases.  If you use a <literal>\parbox</literal> command or
+or a <literal>minipage</literal> then &latex; is put into paragraph mode.  But it
+will not put a page break here.  Inside one of these boxes, called a
+<firstterm>parbox</firstterm>, &latex; is in <firstterm>inner paragraph mode</firstterm>.  Its more usual
+situation, where it can put page breaks, is <firstterm>outer paragraph mode</firstterm>
+(see <link linkend="Page-breaking">Page breaking</link>).
+</para>
 
 <sect1 label="17.1" id="_005censuremath">
 <title><literal>\ensuremath</literal></title>
@@ -8668,33 +11312,22 @@
 </para>
 <screen>\ensuremath{<replaceable>formula</replaceable>}
 </screen>
-<para>The <literal>\ensuremath</literal> command ensures that <replaceable>formula</replaceable> is typeset in
-math mode whatever the current mode in which the command is used.
+<para>Ensure that <replaceable>formula</replaceable> is typeset in math mode.
 </para>
-<para>For instance:
+<para>For instance, you can redefine commands that ordinarily can be used only
+in math mode, so that they can be used both in math and in plain text.
 </para>
-<screen>\documentclass{report}
-\newcommand{\ab}{\ensuremath{(\delta, \varepsilon)}}
-\begin{document}
-Now, the \ab\ pair is equal to \(\ab = (\frac{1}{\pi}, 0)\), ...
-\end{document}
+<screen>\newcommand{\dx}{\ensuremath{dx}}
+In $\int f(x)\, \dx$, the \dx{} is an infinitesimal.
 </screen>
-<para>One can redefine commands that can be used only in math mode so that
-they ca be used in any mode like in the following example given for
-<literal>\leadsto</literal>:
+<para>Caution: the <literal>\ensuremath</literal> command is useful but not a panacea.
 </para>
-<!-- Vincent 2 Karl : "Tous les chemins mènent à Rome" is a French saying -->
-<!-- meaning that there are many different ways to get the same result. I -->
-<!-- am not sure whether in English the given example is also funny. -->
-<screen>\documentclass{report}
-\usepackage{amssymb}
-\newcommand{\originalMeaningOfLeadsTo}{}
-\let\originalMeaningOfLeadsTo\leadsto
-\renewcommand\leadsto{\ensuremath{\originalMeaningOfLeadsTo}}
-\begin{document}
-All roads \leadsto\ Rome.
-\end{document}
+<screen>\newcommand{\alf}{\ensuremath{\alpha}}
+You get an alpha in text mode: \alf.
+But compare the correct spacing in $\alf+\alf$ with that in \alf+\alf.
 </screen>
+<para>Best is to typeset math things in a math mode.
+</para>
 
 </sect1>
 </chapter>
@@ -8704,50 +11337,103 @@
 <indexterm role="cp"><primary>styles, page</primary></indexterm>
 <indexterm role="cp"><primary>page styles</primary></indexterm>
 
-<para>The <literal>\documentclass</literal> command determines the size and position of
-the page’s head and foot.  The page style determines what goes in them.
+<para>The style of a page determines where &latex; places the components of
+that page, such as headers and footers, and the text body.  This
+includes pages in the main part of the document but also includes
+special pages such as the title page of a book, a page from an index, or
+the first page of an article.
 </para>
+<indexterm role="cp"><primary>package, <literal>fancyhdr</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>fancyhdr</literal> package</primary></indexterm>
 
+<para>The package <filename>fancyhdr</filename> is very helpful for constructing page
+styles.  See its documentation on CTAN.
+</para>
 
+
 <sect1 label="18.1" id="_005cmaketitle">
 <title><literal>\maketitle</literal></title>
 
 <indexterm role="cp"><primary>titles, making</primary></indexterm>
 <indexterm role="fn"><primary>\maketitle</primary></indexterm>
 
-<para>The <literal>\maketitle</literal> command generates a title on a separate title
-page—except in the <literal>article</literal> class, where the title is placed
-at the top of the first page.  Information used to produce the title
-is obtained from the following declarations:
+<para>Synopsis:
 </para>
-<variablelist><varlistentry><term><indexterm role="fn"><primary>\author{<replaceable>name</replaceable> \and <replaceable>name2</replaceable>}</primary></indexterm><literal>\author{<replaceable>name</replaceable> \and <replaceable>name2</replaceable>}</literal>
+<screen>\maketitle
+</screen>
+<para>Generate a title.  In the standard classes the title appears on a
+separate page, except in the <literal>article</literal> class where it is at the top
+of the first page.  (See <link linkend="Document-class-options">Document class options</link> for information about
+the <literal>titlepage</literal> document class option.)
+</para>
+<para>This example shows <literal>\maketitle</literal> appearing in its usual place,
+immediately after <literal>\begin{document}</literal>.
+</para>
+<screen>\documentclass{article}
+\title{Constructing a Nuclear Reactor Using Only Coconuts}
+\author{Jonas Grumby\thanks{%
+    With the support of a Ginger Grant from the Roy Hinkley Society.} \\
+  Skipper, \textit{Minnow}
+  \and
+  Willy Gilligan\thanks{%
+    Thanks to the Mary Ann Summers foundation
+    and to Thurston and Lovey Howell.}           \\
+  Mate, \textit{Minnow}
+  }
+\date{1964-Sep-26}
+\begin{document}
+\maketitle
+Just sit right back and you'll hear a tale, a tale of a fateful trip.
+That started from this tropic port, aboard this tiny ship. The mate was
+a mighty sailin' man, the Skipper brave and sure. Five passengers set
+sail that day for a three hour tour. A three hour tour.
+  ...
+</screen>
+<para>You tell &latex; the information used to produce the title by making
+the following declarations.  These must come before the
+<literal>\maketitle</literal>, either in the preamble or in the document body.
+</para>
+<variablelist><varlistentry><term><indexterm role="fn"><primary>\author{<replaceable>name1</replaceable> \and <replaceable>name2</replaceable> \and ...}</primary></indexterm><literal>\author{<replaceable>name1</replaceable> \and <replaceable>name2</replaceable> \and ...}</literal>
 </term><listitem><indexterm role="cp"><primary>author, for titlepage</primary></indexterm>
 <indexterm role="fn"><primary>\\ for <literal>\author</literal></primary></indexterm>
 <indexterm role="fn"><primary>\and for <literal>\author</literal></primary></indexterm>
-<para>The <literal>\author</literal> command declares the document author(s), where the
-argument is a list of authors separated by <literal>\and</literal> commands.  Use
-<literal>\\</literal> to separate lines within a single author’s entry—for
-example, to give the author’s institution or address.
+<para>Required.  Declare the document author or authors.  The argument is a
+list of authors separated by <literal>\and</literal> commands.  To separate lines
+within a single author’s entry, for instance to give the author’s
+institution or address, use a double backslash, <literal>\\</literal>.  If you omit
+the <literal>\author</literal> declaration then you get ‘<literal>LaTeX Warning: No
+\author given</literal>’.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\date{<replaceable>text</replaceable>}</primary></indexterm><literal>\date{<replaceable>text</replaceable>}</literal>
 </term><listitem><indexterm role="cp"><primary>date, for titlepage</primary></indexterm>
-<para>The <literal>\date</literal> command declares <replaceable>text</replaceable> to be the document’s
-date.  With no <literal>\date</literal> command, the current date (see <link linkend="_005ctoday">\today</link>)
-is used.
+<para>Optional.  Declare <replaceable>text</replaceable> to be the document’s date.  The <replaceable>text</replaceable>
+doesn’t need to be in a date format; it can be any text at all.  If you
+omit <literal>\date</literal> then &latex; uses the current date (see <link linkend="_005ctoday">\today</link>).
+To have no date, instead use <literal>\date{}</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\thanks{<replaceable>text</replaceable>}</primary></indexterm><literal>\thanks{<replaceable>text</replaceable>}</literal>
 </term><listitem><indexterm role="cp"><primary>thanks, for titlepage</primary></indexterm>
 <indexterm role="cp"><primary>credit footnote</primary></indexterm>
-<para>The <literal>\thanks</literal> command produces a <literal>\footnote</literal> to the title,
-usually used for credit acknowledgements.
+<para>Optional.  Produce a footnote.  You can use it in the author information
+for acknowledgements, as illustrated below, but you can also use it in
+the title, or any place a footnote makes sense.  It can be any text so
+you can use it to print an email address, or for any purpose.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\title{<replaceable>text</replaceable>}</primary></indexterm><literal>\title{<replaceable>text</replaceable>}</literal>
 </term><listitem><indexterm role="cp"><primary>title, for titlepage</primary></indexterm>
 <indexterm role="fn"><primary>\\ for <literal>\title</literal></primary></indexterm>
-<para>The <literal>\title</literal> command declares <replaceable>text</replaceable> to be the title of the
-document.  Use <literal>\\</literal> to force a line break, as usual.
+<para>Required.  Declare <replaceable>text</replaceable> to be the title of the document.  Get line
+breaks inside <replaceable>text</replaceable> with a double backslash, <literal>\\</literal>.  If you
+omit the <literal>\title</literal> declaration then you get ‘<literal>LaTeX Error: No
+\title given</literal>’.
 </para>
 </listitem></varlistentry></variablelist>
+<para>Many publishers will provide a class to use in place of <literal>article</literal>
+in that example, that formats the title according to their house
+requirements.  To make your own, see <link linkend="titlepage">titlepage</link>. You can
+either create this as a one-off or you can include it as part of a
+renewed <literal>\maketitle</literal> command.
+</para>
 
 </sect1>
 <sect1 label="18.2" id="_005cpagenumbering">
@@ -8758,27 +11444,62 @@
 
 <para>Synopsis:
 </para>
-<screen>\pagenumbering{<replaceable>style</replaceable>}
+<screen>\pagenumbering{<replaceable>number-style</replaceable>}
 </screen>
-<para>Specifies the style of page numbers, according to <replaceable>style</replaceable>; also
-resets the page number to 1.  The <replaceable>style</replaceable> argument is one of
-the following:
+<para>Specifies the style of page numbers, and resets the page number.  The
+numbering style is reflected on the page, and also in the table of
+contents and other page references.  This declaration has global scope
+so its effect is not delimited by braces or environments.
 </para>
+<para>In this example, before the Main section the pages are numbered
+‘<literal>a</literal>’, etc.  Starting on the page containing that section, the pages
+are numbered ‘<literal>1</literal>’, etc.
+</para>
+<screen>\begin{document}\pagenumbering{alph}
+  ...
+\section{Main}\pagenumbering{arabic}
+  ...
+</screen>
+<para>The argument <replaceable>number-style</replaceable> is one of the following (see
+also <link linkend="_005calph-_005cAlph-_005carabic-_005croman-_005cRoman-_005cfnsymbol">\alph \Alph \arabic \roman \Roman \fnsymbol</link>).
+</para>
 <variablelist><varlistentry><term><literal>arabic</literal>
-</term><listitem><para>arabic numerals
+</term><listitem><para>arabic numerals: 1, 2, … 
 </para>
 </listitem></varlistentry><varlistentry><term><literal>roman</literal>
-</term><listitem><para>lowercase Roman numerals
+</term><listitem><para>lowercase Roman numerals: i, ii, …
 </para>
 </listitem></varlistentry><varlistentry><term><literal>Roman</literal>
-</term><listitem><para>uppercase Roman numerals
+</term><listitem><para>uppercase Roman numerals: I, II, …
 </para>
 </listitem></varlistentry><varlistentry><term><literal>alph</literal>
-</term><listitem><para>lowercase letters
+</term><listitem><para>lowercase letters: a, b, … If you have more than 26 pages then you
+get ‘<literal>LaTeX Error: Counter too large</literal>’.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>Alph</literal>
-</term><listitem><para>uppercase letters
-</para></listitem></varlistentry></variablelist>
+</term><listitem><para>uppercase letters: A, B, … If you have more than 26 pages then you
+get ‘<literal>LaTeX Error: Counter too large</literal>’.
+</para>
+</listitem></varlistentry><varlistentry><term><literal>gobble</literal>
+</term><listitem><indexterm role="cp"><primary>package, <literal>hyperref</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>hyperref</literal> package</primary></indexterm>
+<para>&latex; does not output a page number, although it
+does get reset.  References to that page also are blank.  (This does not
+work with the popular package <filename>hyperref</filename> so to have the page number
+not appear you may want to instead use <literal>\pagestyle{empty}</literal> or
+<literal>\thispagestyle{empty}</literal>.)
+</para>
+</listitem></varlistentry></variablelist>
+<para>Traditionally, if a document has front matter—preface, table of
+contents, etc.—then it is numbered with lowercase Roman numerals. The
+main matter of a document uses arabic.  See <link linkend="_005cfrontmatter-_0026-_005cmainmatter-_0026-_005cbackmatter">\frontmatter & \mainmatter
+& \backmatter</link>.
+</para>
+<para>If you want to address where the page number appears on the page,
+see <link linkend="_005cpagestyle">\pagestyle</link>.  If you want to change the value of page
+number then you will manipulate the <literal>page</literal> counter
+(see <link linkend="Counters">Counters</link>).
+</para>
 
 </sect1>
 <sect1 label="18.3" id="_005cpagestyle">
@@ -8793,49 +11514,125 @@
 </para>
 <screen>\pagestyle{<replaceable>style</replaceable>}
 </screen>
-<para>The <literal>\pagestyle</literal> command specifies how the headers and footers
-are typeset from the current page onwards.  Values for <replaceable>style</replaceable>:
+<para>Declaration that specifies how the page headers and footers are typeset,
+from the current page onwards.
 </para>
+<indexterm role="cp"><primary>package, <literal>fancyhdr</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>fancyhdr</literal> package</primary></indexterm>
+
+<para>A discussion with an example is below.  Note first that the package
+<filename>fancyhdr</filename> is now the standard way to manipulate headers and
+footers.  New documents that need to do anything other than one of the
+standard options below should use this package.  See its documentation
+on CTAN.
+</para>
+<para>Values for <replaceable>style</replaceable>:
+</para>
 <variablelist><varlistentry><term><literal>plain</literal>
-</term><listitem><para>Just a plain page number.
+</term><listitem><para>The header is empty.  The footer contains only a page number, centered.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>empty</literal>
-</term><listitem><para>Empty headers and footers, e.g., no page numbers.
+</term><listitem><para>The header and footer is empty.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>headings</literal>
-</term><listitem><para>Put running headers on each page.  The document style specifies what
-goes in the headers.
+</term><listitem><para>Put running headers and footers on each page.  The document style
+specifies what goes in there; see the discussion below.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>myheadings</literal>
 </term><listitem><para>Custom headers, specified via the <literal>\markboth</literal> or the
 <literal>\markright</literal> commands.
 </para>
 </listitem></varlistentry></variablelist>
+<para>Some discussion of the motivation for &latex;’s mechanism will help you
+work with the options <literal>headings</literal> or <literal>myheadings</literal>.  The
+document source below produces an article, two-sided, with the pagestyle
+<literal>headings</literal>.  On this document’s left hand pages, &latex; wants (in
+addition to the page number) the title of the current section.  On its
+right hand pages &latex; wants the title of the current subsection.
+When it makes up a page, &latex; gets this information from the
+commands <literal>\leftmark</literal> and <literal>\rightmark</literal>.  So it is up to
+<literal>\section</literal> and <literal>\subsection</literal> to store that information there.
+</para>
+<screen>\documentclass[twoside]{article}
+\pagestyle{headings}
+\begin{document}
+  ... \section{Section 1} ... \subsection{Subsection 1.1} ...
+\section{Section 2}
+  ...
+\subsection{Subsection 2.1}
+  ...
+\subsection{Subsection 2.2}
+  ...
+</screen>
+<para>Suppose that the second section falls on a left page.  Although when the
+page starts it is in the first section, &latex; will put
+‘<literal>Section 2</literal>’ in the left page header.  As to the right header,
+if no subsection starts before the end of the right page then &latex;
+blanks the right hand header.  If a subsection does appear before the
+right page finishes then there are two cases.  If at least one
+subsection starts on the right hand page then &latex; will put in the
+right header the title of the first subsection starting on that right
+page.  If at least one of 2.1, 2.2, …, starts on the left page but
+none starts on the right then &latex; puts in the right hand header the
+title of the last subsection to start, that is, the one in effect during
+the right hand page.
+</para>
+<para>To accomplish this, in a two-sided article, &latex; has <literal>\section</literal>
+issue a command <literal>\markboth</literal>, setting <literal>\leftmark</literal>
+to ‘<literal>Section 2</literal>’ and setting <literal>\rightmark</literal> to blank.
+And, &latex; has <literal>\subsection</literal> issue a command <literal>\markright</literal>,
+setting <literal>\rightmark</literal> to ‘<literal>Subsection 2.1</literal>’, etc.
+</para>
 <para>Here are the descriptions of <literal>\markboth</literal> and <literal>\markright</literal>:
 </para>
-<variablelist><varlistentry><term><indexterm role="fn"><primary>\markboth{<replaceable>left</replaceable>}{<replaceable>right</replaceable>}</primary></indexterm><literal>\markboth{<replaceable>left</replaceable>}{<replaceable>right</replaceable>}</literal>
-</term><listitem><para>Sets both the left and the right heading.  A “left-hand heading”
-(<replaceable>left</replaceable>) is generated by the last <literal>\markboth</literal> command before
-the end of the page, while a “right-hand heading” (<replaceable>right</replaceable>) is
-generated by the first <literal>\markboth</literal> or <literal>\markright</literal> that
-comes on the page if there is one, otherwise by the last one before
-the page.
+<variablelist><varlistentry><term><indexterm role="fn"><primary>\markboth{<replaceable>left-head</replaceable>}{<replaceable>right-head</replaceable>}</primary></indexterm><literal>\markboth{<replaceable>left-head</replaceable>}{<replaceable>right-head</replaceable>}</literal>
+</term><listitem><para>Sets both the right hand and left hand heading information for either a
+page style of <literal>headings</literal> or <literal>myheadings</literal>.  A left hand page
+heading <replaceable>left-head</replaceable> is generated by the last <literal>\markboth</literal>
+command before the end of the page.  A right hand page heading
+<replaceable>right-head</replaceable> is generated by the first <literal>\markboth</literal> or
+<literal>\markright</literal> that comes on the page if there is one, otherwise by
+the last one that came before that page.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\markright{<replaceable>right</replaceable>}</primary></indexterm><literal>\markright{<replaceable>right</replaceable>}</literal>
-</term><listitem><para>Sets the right heading, leaving the left heading unchanged.
+</term><listitem><para>Sets the right hand page heading, leaving the left unchanged.
 </para>
 </listitem></varlistentry></variablelist>
 
 </sect1>
 <sect1 label="18.4" id="_005cthispagestyle">
-<title><literal>\thispagestyle{<replaceable>style</replaceable>}</literal></title>
+<title><literal>\thispagestyle</literal></title>
 
 <indexterm role="fn"><primary>\thispagestyle</primary></indexterm>
+<indexterm role="cp"><primary>page style, this page</primary></indexterm>
 
-<para>The <literal>\thispagestyle</literal> command works in the same manner as the
-<literal>\pagestyle</literal> command (see previous section) except that it
-changes to <replaceable>style</replaceable> for the current page only.
+<para>Synopsis:
 </para>
+<screen>\thispagestyle{<replaceable>style</replaceable>}
+</screen>
+<para>Works in the same way as the <literal>\pagestyle</literal> (see <link linkend="_005cpagestyle">\pagestyle</link>),
+except that it changes to <replaceable>style</replaceable> for the current page only.  This
+declaration has global scope, so its effect is not delimited by braces
+or environments.
+</para>
+<para>Often the first page of a chapter or section has a different style.  For
+example, this &latex; book document has the first page of the first
+chapter in in <literal>plain</literal> style, as is the default (see <link linkend="Page-styles">Page
+styles</link>).
+</para>
+<screen>\documentclass{book}
+\pagestyle{headings}
+\begin{document}
+\chapter{First chapter}
+  ...
+\chapter{Second chapter}\thispagestyle{empty}
+  ...
+</screen>
+<para>The <literal>plain</literal> style has a page number on it, centered in the footer.
+To make the page entirely empty, the command
+<literal>\thispagestyle{empty}</literal> immediately follows the second
+<literal>\chapter</literal>.
+</para>
 
 </sect1>
 </chapter>
@@ -8845,60 +11642,169 @@
 <indexterm role="cp"><primary>spaces</primary></indexterm>
 <indexterm role="cp"><primary>white space</primary></indexterm>
 
-<para>&latex; has many ways to produce white (or filled) space.
+<para>&latex; has many ways to produce white (or filled) space.  Some of
+these are best suited to mathematical text; see <link linkend="Spacing-in-math-mode">Spacing in
+math mode</link>.  Some spacing commands are suitable for both regular text
+and mathematical text; versions of some of these commands are in this
+chapter.
 </para>
 
 
-<sect1 label="19.1" id="_005chspace">
+<sect1 label="19.1" id="_005censpace-_0026-_005cquad-_0026-_005cqquad">
+<title><literal>\enspace</literal> & <literal>\quad</literal> & <literal>\qquad</literal></title>
+
+<indexterm role="fn"><primary>\enspace</primary></indexterm>
+<indexterm role="fn"><primary>\quad</primary></indexterm>
+<indexterm role="fn"><primary>\qquad</primary></indexterm>
+
+<para>Synopsis, one of:
+</para>
+<screen>\enspace
+\quad
+\qquad
+</screen>
+<para>Insert a horizontal space of 1/2em, 1em, or 2em. The
+em is a length defined by a font designer, often thought of as being the
+width of a capital M.  One advantage of describing space in ems is
+that it can be more portable across documents than an absolute
+measurement such as points (see <link linkend="Lengths_002fem">Lengths/em</link>).
+</para>
+<para>This puts a suitable gap between two graphics.
+</para>
+<screen>\begin{center}
+  \includegraphics{womensmile.png}%
+  \qquad\includegraphics{mensmile.png}
+\end{center}
+</screen>
+<para>See <link linkend="Spacing-in-math-mode">Spacing in math mode</link> for <literal>\quad</literal> and <literal>\qquad</literal>.  These
+are lengths from centuries of typesetting and so may be a better choice
+in many circumstances than arbitrary lengths, such as you get with
+<literal>\hspace</literal>.
+</para>
+
+</sect1>
+<sect1 label="19.2" id="_005chspace">
 <title><literal>\hspace</literal></title>
 
 <indexterm role="fn"><primary>\hspace</primary></indexterm>
 
-<para>Synopsis:
+<para>Synopsis, one of:
 </para>
 <screen>\hspace{<replaceable>length</replaceable>}
 \hspace*{<replaceable>length</replaceable>}
 </screen>
-<para>Add the horizontal space given by <replaceable>length</replaceable>.  The <replaceable>length</replaceable> is a
-rubber length, that is, it may contain a <literal>plus</literal> or <literal>minus</literal>
-component, in any unit that &latex; understands (see <link linkend="Lengths">Lengths</link>).
+<para>Insert the horizontal space <replaceable>length</replaceable>.  The <replaceable>length</replaceable> can be
+positive, negative, or zero; adding negative space is like backspacing.
+It is a rubber length, that is, it may contain a <literal>plus</literal> or
+<literal>minus</literal> component, or both (see <link linkend="Lengths">Lengths</link>).  Because the space is
+stretchable and shrinkable, it is sometimes called <firstterm>glue</firstterm>.
 </para>
-<para>This command can add both positive and negative space; adding negative
-space is like backspacing.
+<para>This makes a line with ‘<literal>Name:</literal>’ an inch from the right margin.
 </para>
-<para>Normally when &tex; breaks a paragraph into lines it discards white
-space (glues and kerns) that would come at the start of a line, so you
-get an inter-word space or a line break between words but not both. This
-command’s starred version <literal>\hspace*{...}</literal> puts a non-discardable
-invisible item in front of the space, so the space appears in the
-output.
+<screen>\noindent\makebox[\linewidth][r]{Name:\hspace{1in}}
+</screen>
+<para>The <literal>*</literal>-version inserts horizontal space that non-discardable.
+More precisely, when &tex; breaks a paragraph into lines any white
+space—glues and kerns—that come at a line break are discarded.  The
+<literal>*</literal>-version avoids that (technically, it adds a non-discardable
+invisible item in front of the space).
 </para>
-<para>This example make a one-line paragraph that puts ‘<literal>Name:</literal>’ an inch
-from the right margin.
+<para>In this example
 </para>
-<screen>\noindent\makebox[\linewidth]{\hspace{\fill}Name:\hspace{1in}}
+<screen>\parbox{0.8\linewidth}{%
+  Fill in each blank: Four \hspace*{1in} and seven years ago our
+  fathers brought forth on this continent, a new \hspace*{1in},
+  conceived in \hspace*{1in}, and dedicated to the proposition
+  that all men are created \hspace*{1in}.}
 </screen>
+<para>the 1 inch blank following ‘<literal>conceived in</literal>’ falls at the start
+of a line.  If you erase the <literal>*</literal> then &latex; discards the blank.
+</para>
+<para>Here, the <literal>\hspace</literal> separates the three graphics.
+</para>
+<screen>\begin{center}
+  \includegraphics{lion.png}%   comment keeps out extra space
+  \hspace{1cm minus 0.25cm}\includegraphics{tiger.png}%
+  \hspace{1cm minus 0.25cm}\includegraphics{bear.png}
+\end{center}
+</screen>
+<para>Because the argument to each <literal>\hspace</literal> has <literal>minus 0.25cm</literal>,
+each can shrink a little if the three figures are too wide.  But each
+space won’t shrink more than 0.25cm (see <link linkend="Lengths">Lengths</link>).
+</para>
 
 </sect1>
-<sect1 label="19.2" id="_005chfill">
+<sect1 label="19.3" id="_005chfill">
 <title><literal>\hfill</literal></title>
 
 <indexterm role="fn"><primary>\hfill</primary></indexterm>
 
 <indexterm role="cp"><primary>stretch, infinite horizontal</primary></indexterm>
 <indexterm role="cp"><primary>infinite horizontal stretch</primary></indexterm>
-<para>Produce a rubber length which has
-no natural space but can stretch horizontally as far as
-needed (see <link linkend="Lengths">Lengths</link>).
+
+<para>Synopsis:
 </para>
+<screen>\hfill
+</screen>
+<para>Produce a rubber length which has no natural space but that can stretch
+horizontally as far as needed (see <link linkend="Lengths">Lengths</link>).
+</para>
+<para>This creates a one-line paragraph with ‘<literal>Name:</literal>’ on the left side
+of the page and ‘<literal>Quiz One</literal>’ on the right.
+</para>
+<screen>\noindent Name:\hfill Quiz One
+</screen>
 <indexterm role="fn"><primary>\fill</primary></indexterm>
-<para>The command <literal>\hfill</literal> is equivalent to <literal>\hspace{\fill}</literal>.  For
-space that does not disappear at line breaks use
-<literal>\hspace*{\fill}</literal> instead (see <link linkend="_005chspace">\hspace</link>).
+<para>The <literal>\hfill</literal> command is equivalent to <literal>\hspace{\fill}</literal> and
+so the space can be discarded at line breaks.  To avoid that instead use
+<literal>\hspace*{\fill}</literal> (see <link linkend="_005chspace">\hspace</link>).
 </para>
+<para>Here the graphs are evenly spaced in the middle of the figure.
+</para>
+<screen>\newcommand*{\vcenteredhbox}[1]{\begin{tabular}{@{}c@{}}#1\end{tabular}}
+  ...
+\begin{figure}
+  \hspace*{\fill}%
+  \vcenteredhbox{\includegraphics{graph0.png}}%
+    \hfill\vcenteredhbox{\includegraphics{graph1.png}}%
+  \hspace*{\fill}%
+  \caption{Comparison of two graphs} \label{fig:twographs}
+\end{figure}
+</screen>
+<para>Note the <literal>\hspace*</literal>’s where the space could otherwise be dropped.
+</para>
 
 </sect1>
-<sect1 label="19.3" id="_005cspacefactor">
+<sect1 label="19.4" id="_005chss">
+<title><literal>\hss</literal></title>
+
+<indexterm role="fn"><primary>\hss</primary></indexterm>
+<indexterm role="cp"><primary>horizontal space</primary></indexterm>
+<indexterm role="cp"><primary>horizontal space, stretchable</primary></indexterm>
+<indexterm role="cp"><primary>space, inserting horizontal</primary></indexterm>
+
+<para>Synopsis:
+</para>
+<screen>\hss
+</screen>
+<para>Produce a horizontal space that is infinitely shrinkable as well as
+infinitely stretchable (this command is a &tex; primitive).  &latex;
+authors should reach first for the <literal>\makebox</literal> command to get the
+effects of <literal>\hss</literal> (see <link linkend="_005cmbox-_0026-_005cmakebox">\mbox & \makebox</link>).
+</para>
+<para>Here, the first line’s <literal>\hss</literal> makes the Z stick out to the right,
+overwriting the Y.  In the second line the Z sticks out to the left,
+overwriting the X.
+</para>
+<screen>X\hbox to 0pt{Z\hss}Y
+X\hbox to 0pt{\hss Z}Y
+</screen>
+<para>Without the <literal>\hss</literal> you get something like ‘<literal>Overfull \hbox
+(6.11111pt too wide) detected at line 20</literal>’.
+</para>
+
+</sect1>
+<sect1 label="19.5" id="_005cspacefactor">
 <title><literal>\spacefactor</literal></title>
 
 <para>Synopsis:
@@ -8906,25 +11812,27 @@
 <screen>\spacefactor=<replaceable>integer</replaceable>
 </screen>
 <indexterm role="fn"><primary>\spacefactor</primary></indexterm>
-<para>While &latex; is making the page, to give the lines the best appearance
-it may stretch or shrink the gaps between words.  The
-<literal>\spacefactor</literal> command (from Plain &tex;) allows you to
-change the &latex;’s default behavior.
+<para>Influence &latex;’s glue stretch and shrink behavior.  Most user-level
+documents do not use this command.
 </para>
+<para>While &latex; is laying out the material, it may stretch or shrink the
+gaps between words.  (This space is not a character; it is called the
+<firstterm>interword glue</firstterm>; see <link linkend="_005chspace">\hspace</link>).  The <literal>\spacefactor</literal> command
+(from Plain &tex;) allows you to, for instance, have the space
+after a period stretch more than the space after a word-ending letter.
+</para>
 <para>After &latex; places each character, or rule or other box, it sets a
 parameter called the <firstterm>space factor</firstterm>.  If the next thing in the input
-is a space then this parameter affects how much of a horizontal gap
-&latex; will have it span.  (This gap is not a character; it is called
-<firstterm>interword glue</firstterm>.)  A larger space factor means that the glue gap
-can stretch more and shrink less.
+is a space then this parameter affects how much stretching or shrinking
+can happen.  A space factor that is larger than the normal value means
+that the glue can stretch more and shrink less.  Normally, the space
+factor is 1000. This value is in effect following most characters, and
+any non-character box or math formula.  But it is 3000 after a period,
+exclamation mark, or question mark, it is 2000 after a colon, 1500 after
+a semicolon, 1250 after a comma, and 0 after a right parenthesis or
+bracket, or closing double quote or single quote.  Finally, it is 999
+after a capital letter.
 </para>
-<para>Normally, the space factor is 1000; this value is in effect following
-most characters, and any non-character box or math formula.  But it is
-3000 after a period, exclamation mark, or question mark, it is 2000
-after a colon, 1500 after a semicolon, 1250 after a comma, and 0 after a
-right parenthesis or bracket, or closing double quote or single quote.
-Finally, it is 999 after a capital letter.
-</para>
 <para>If the space factor <replaceable>f</replaceable> is 1000 then the glue gap will be the
 font’s normal space value (for Computer Modern Roman 10 point this is
 3.3333 points).  Otherwise, if the space factor <replaceable>f</replaceable> is greater
@@ -8932,304 +11840,606 @@
 Modern Roman 10 point this is 1.11111 points), and then the font’s
 normal stretch value is multiplied by <inlineequation><mathphrase>f /1000</mathphrase></inlineequation> and the normal
 shrink value is multiplied by <inlineequation><mathphrase>1000/f</mathphrase></inlineequation> (for Computer Modern Roman
-10 point these are 1.66666 and 1.11111 points).  In short, compared
-to a normal space, such as the space following a word ending in a
-lowercase letter, inter-sentence spacing has a fixed extra space added
-and then the space can stretch 3 times as much and shrink 1/3 as much.
+10 point these are 1.66666 and 1.11111 points).
 </para>
-<para>The rules for how &tex; uses space factors are even more complex
-because they play two more roles.  In practice, there are two
-consequences.  First, if a period or other punctuation is followed by a
-close parenthesis or close double quote then its effect is still in
-place, that is, the following glue will have increased stretch and
-shrink.  Second, conversely, if punctuation comes after a capital letter
-then its effect is not in place so you get an ordinary space.  For how
-to adjust to this second case, for instance if an abbreviation does not
-end in a capital letter, see <link linkend="_005c_0028SPACE_0029-and-_005c_0040">\(SPACE) and \@</link>.
+<para>For example, consider the period ending <literal>A man's best friend is his
+dog.</literal>  After it, &tex; puts in a fixed extra space, and also allows the
+glue to stretch 3 times as much and shrink 1/3 as much, as the glue
+after <literal>friend</literal>, which does not end in a period.
 </para>
+<para>The rules for space factors are even more complex because they play
+additional roles.  In practice, there are two consequences.  First, if a
+period or other punctuation is followed by a right parenthesis or
+bracket, or right single or double quote then the spacing effect of that
+period carries through those characters (that is, the following glue
+will have increased stretch and shrink).  Second, if
+punctuation comes after a capital letter then its effect is not in place
+so you get an ordinary space.  This second case also affects abbreviations
+that do not end in a capital letter (see <link linkend="_005c_0040">\@</link>).
+</para>
+<para>You can only use <literal>\spacefactor</literal> in paragraph mode or LR mode
+(see <link linkend="Modes">Modes</link>).  You can see the current value with
+<literal>\the\spacefactor</literal> or <literal>\showthe\spacefactor</literal>.
+</para>
+<para>(Comment, not really related to <literal>\spacefactor</literal>: if you get errors
+like ‘<literal>You can't use `\spacefactor' in vertical mode</literal>’, or ‘<literal>You
+can't use `\spacefactor' in math mode.</literal>’, or ‘<literal>Improper \spacefactor</literal>’
+then you have probably tried to redefine an internal command.
+See <link linkend="_005cmakeatletter-_0026-_005cmakeatother">\makeatletter & \makeatother</link>.)
+</para>
 
 
 
-<sect2 label="19.3.1" id="_005c_0028SPACE_0029-and-_005c_0040">
-<title><literal>\(SPACE)</literal> and <literal>\@</literal></title>
+<sect2 label="19.5.1" id="_005c_0040">
+<title><literal>\@</literal></title>
 
-<indexterm role="fn"><primary>\(SPACE)</primary></indexterm>
-<indexterm role="fn"><primary>\TAB</primary></indexterm>
-<indexterm role="fn"><primary>\NEWLINE</primary></indexterm>
 <indexterm role="fn"><primary>\@</primary></indexterm>
+<indexterm role="fn"><primary>at-sign</primary></indexterm>
+<indexterm role="cp"><primary>period, sentence-ending</primary></indexterm>
+<indexterm role="cp"><primary>period, abbreviation-ending</primary></indexterm>
+<indexterm role="cp"><primary>period, spacing after</primary></indexterm>
 <anchor id="_005cAT"/><!-- old name -->
 
-<para>Here, <literal>\(SPACE)</literal> means a backslash followed by a space.  These
-commands mark a punctuation character, typically a period, as either
-ending a sentence or as ending an abbreviation.
+<para>Synopsis:
 </para>
-<para>By default, in justifying a line &latex; adjusts the space after a
-sentence-ending period (or a question mark, exclamation point, comma, or
-colon) more than the space between words.  See <link linkend="_005cspacefactor">\spacefactor</link>. As
-described there, &latex; assumes that the period ends a sentence unless
-it is preceded by a capital letter, in which case it takes that period
-for part of an abbreviation.  Note that if a sentence-ending period is
-immediately followed by a right parenthesis or bracket, or right single
-or double quote, then the space effect of that period follows through
-that parenthesis or quote.
+<screen><replaceable>capital-letter</replaceable>\@.    
+</screen>
+<para>Treat a period as sentence-ending, where &latex; would otherwise think
+it is part of an abbreviation.  &latex; thinks that a period ends an
+abbreviation if the period comes after a capital letter, and otherwise
+thinks the period ends the sentence.  By default, in justifying a line
+&latex; adjusts the space after a sentence-ending period (or a question
+mark, exclamation point, comma, or colon) more than it adjusts the space
+between words (see <link linkend="_005cspacefactor">\spacefactor</link>).
 </para>
-<para>So: if you have a period ending an abbreviation whose last letter is not
-a capital letter, and that abbreviation is not the last word in the
-sentence, then follow that period with a backslash-space (<literal>\ </literal>) or
-a tie (<literal>~</literal>) or a <literal>\@</literal>.  Examples are <literal>Nat.\ Acad.\
-Science</literal>, and <literal>Mr.~Bean</literal>, and <literal>(manure, etc.\@) for sale</literal>
-(note that in the last the <literal>\@</literal> comes before the closing parenthesis).
+<para>This example shows the two cases to remember.
 </para>
-<para>In the opposite situation, if you have a capital letter followed by a
-period that does end the sentence, then put <literal>\@</literal> before the
-period.  For example, <literal>book by the MAA\@.</literal> will have correct
-inter-sentence spacing after the period.
+<screen>The songs \textit{Red Guitar}, etc.\ are by Loudon Wainwright~III\@.
+</screen>
+<para>The second period ends the sentence, despite that it is preceded by a
+capital.  We tell &latex; that it ends the sentence by putting
+<literal>\@</literal> before it.  The first period ends the abbreviation
+‘<literal>etc.</literal>’ but not the sentence.  The backslash-space, <literal>\ </literal>,
+produces a mid-sentence space.
 </para>
-<para>For another use of <literal>\(SPACE)</literal>, see <link linkend="_005c_0028SPACE_0029-after-control-sequence">\(SPACE) after control sequence</link>.
+<para>So: if you have a capital letter followed by a period that ends the
+sentence, then put <literal>\@</literal> before the period.  This holds even if
+there is an intervening right parenthesis or bracket, or right single or
+double quote, because the spacing effect of that period carries through
+those characters.  For example, this
 </para>
+<screen>Use the \textit{Instructional Practices Guide},
+(a book by the MAA)\@.
+</screen>
+<para>will have correct inter-sentence spacing after the period.
+</para>
+<para>The <literal>\@</literal> command is only for a text mode. If you use it outside of
+a text mode then you get ‘<literal>You can't use `\spacefactor' in vertical
+mode</literal>’ (see <link linkend="Modes">Modes</link>).
+</para>
+<para>Comment: the converse case is a period ending an abbreviation whose last
+letter is not a capital letter, and that abbreviation is not the last
+word in the sentence.  For that case follow the period with a
+backslash-space, (<literal>\ </literal>), or a tie, (<literal>~</literal>), or <literal>\@</literal>.
+Examples are <literal>Nat.\ Acad.\ Science</literal>, and <literal>Mr.~Bean</literal>, and
+<literal>(manure, etc.\@) for sale</literal> (note in the last one that the
+<literal>\@</literal> comes before the closing parenthesis).
+</para>
 
 </sect2>
-<sect2 label="19.3.2" id="_005cfrenchspacing">
+<sect2 label="19.5.2" id="_005cfrenchspacing">
 <title><literal>\frenchspacing</literal></title>
 
 <indexterm role="fn"><primary>\frenchspacing</primary></indexterm>
 <indexterm role="fn"><primary>\nonfrenchspacing</primary></indexterm>
 <indexterm role="cp"><primary>spacing, inter-sentence</primary></indexterm>
 
-<para>This declaration (from Plain &tex;) causes &latex; to treat
-inter-sentence spacing in the same way as interword spacing.
+<para>Synopsis, one of:
 </para>
-<para>In justifying the text in a line, some typographic traditions, including
-English, prefer to adjust the space between sentences (or after other
-punctuation marks) more than the space between words.  Following this
-declaration, all spaces are instead treated equally.
+<screen>\frenchspacing
+\nonfrenchspacing
+</screen>
+<para>The first declaration causes &latex; to treat spacing between sentences
+in the same way as spacing between words in the middle of a sentence.
+The second causes spacing between sentences to stretch or shrink more
+(see <link linkend="_005cspacefactor">\spacefactor</link>); this is the default.
 </para>
-<para>Revert to the default behavior by declaring <literal>\nonfrenchspacing</literal>.
+<para>Some typographic traditions, including English, prefer to adjust the
+space between sentences (or spaces following a question mark,
+exclamation point, comma, or colon) more than the space between words
+that are in the middle of a sentence.  Declaring <literal>\frenchspacing</literal>
+(the command is from Plain &tex;) switches to the tradition that all
+spaces are treated equally.
 </para>
 
 </sect2>
-<sect2 label="19.3.3" id="_005cnormalsfcodes">
+<sect2 label="19.5.3" id="_005cnormalsfcodes">
 <title><literal>\normalsfcodes</literal></title>
 
 <indexterm role="fn"><primary>\normalsfcodes</primary></indexterm>
 <indexterm role="cp"><primary>spacing, inter-sentence</primary></indexterm>
 
-<para>Reset the &latex; space factor values to the default.
+<para>Synopsis:
 </para>
+<screen>\normalsfcodes
+</screen>
+<para>Reset the &latex; space factor values to the default
+(see <link linkend="_005cspacefactor">\spacefactor</link>).
+</para>
 
 </sect2>
 </sect1>
-<sect1 label="19.4" id="_005c_0028SPACE_0029-after-control-sequence">
-<title><literal>\ </literal> after control sequence</title>
+<sect1 label="19.6" id="_005c_0028SPACE_0029">
+<title>Backslash-space, <literal>\ </literal></title>
 
-<para>The <literal>\ </literal> command is often used after control sequences to keep
-them from gobbling the space that follows, as in ‘<literal>\TeX\ is nice</literal>’.
-And, under normal circumstances, <literal>\</literal><keycap>tab</keycap> and
-<literal>\</literal><keycap>newline</keycap> are equivalent to <literal>\ </literal>. For another use of
-<literal>\ </literal>, see also <link linkend="_005c_0028SPACE_0029-and-_005c_0040">\(SPACE) and \@</link>.
+<indexterm role="cp"><primary>\NEWLINE</primary></indexterm>
+<indexterm role="cp"><primary>\SPACE</primary></indexterm>
+<indexterm role="cp"><primary>\TAB</primary></indexterm>
+
+<para>This section refers to the command consisting of two characters, a
+backslash followed by a space. Synopsis:
 </para>
-<para>Some people prefer to use <literal>{}</literal> for the same purpose, as in
-<literal>\TeX{} is nice</literal>. This has the advantage that you can always
-write it the same way, namely <literal>\TeX{}</literal>, whether it is followed
-by a space or by a punctuation mark. Compare:
+<screen>\    
+</screen>
+<para>Produce a space. By default it produces white space of length
+3.33333pt plus 1.66666pt minus 1.11111pt.
 </para>
-<screen>\TeX\ is a nice system. \TeX, a nice system.
+<para>A blank is not a space.  When you type a blank between words, &latex;
+produces white space.  That’s different from an explicit space.  This
+illustrates.
+</para>
+<screen>\begin{tabular}{l}
+Three blanks:   in a row \\
+Three spaces:\ \ \ in a row \\
+\end{tabular}
+</screen>
+<para>On the first line &latex; collapses the three blanks to output one
+whitespace (it would be the same with a single blank or, for instance,
+with a blank and an tab and a blank, or a blank and a newline and a
+blank). But the second line asks for three spaces so the white area is
+wider.  Thus, the backslash-space command will create some horizontal
+space.  (But the best way to create horizontal space is with
+<literal>\hspace</literal>; See <link linkend="_005chspace">\hspace</link>.)
+</para>
+<para>The backslash-space command has two main uses.  First, it is often used
+after control sequences to keep them from gobbling the space that
+follows, as in <literal>\TeX\ is nice</literal>.  (But the approach of using curly
+parentheses, as in <literal>\TeX{} is nice</literal>, has the advantage of still
+working if the next character is a period.)
+</para>
+<para>The second common use is that
+it mark  a period as ending an abbreviation instead of ending
+a sentence, as in <literal>So says Prof.\ Smith</literal> (see <link linkend="_005c_0040">\@</link>).
+</para>
+<para>Under normal circumstances, <literal>\</literal><keycap>tab</keycap> and <literal>\</literal><keycap>newline</keycap>
+are equivalent to backslash-space, <literal>\ </literal>.
+</para>
+<!-- @PkgIndex{xspace} -->
+<!-- Some individual commands, notably those defined with the @code{xspace}, -->
+<!-- package do not follow the standard behavior. -->
 
-\TeX{} is a nice system. \TeX{}, a nice system.
+
+</sect1>
+<sect1 label="19.7" id="_007e">
+<title><literal>~</literal></title>
+
+<indexterm role="fn"><primary>~</primary></indexterm>
+<indexterm role="cp"><primary>tie</primary></indexterm>
+<indexterm role="cp"><primary>space, hard</primary></indexterm>
+<indexterm role="cp"><primary>space, unbreakable</primary></indexterm>
+<indexterm role="cp"><primary>NBSP</primary></indexterm>
+
+<para>Synopsis:
+</para>
+<screen><replaceable>before</replaceable>~<replaceable>after</replaceable>
 </screen>
-<indexterm role="cp"><primary>package, <literal>xspace</literal></primary></indexterm>
-<indexterm role="cp"><primary><literal>xspace</literal> package</primary></indexterm>
+<para>The tie character, <literal>~</literal>, produces a space between <replaceable>before</replaceable> and
+<replaceable>after</replaceable> at which the line will not be broken. By default the white
+space has length 3.33333pt plus 1.66666pt minus
+1.11111pt (see <link linkend="Lengths">Lengths</link>).
+</para>
+<para>Here &latex; will not break the line between the final two words.
+</para>
+<screen>Thanks to Prof.~Lerman.
+</screen>
+<para>In addition, despite the period, &latex; does not use the
+end-of-sentence spacing (see <link linkend="_005c_0040">\@</link>).
+</para>
+<para>Ties prevent the end of line separation of things where that could cause
+confusion. But they also reduce &latex;’s options when it breaks lines
+into paragraphs, so you can use too many. They are also matters of
+taste, sometimes alarmingly dogmatic taste, among readers. Nevertheless,
+here are some usage models, many of them from the &tex;book.
+</para>
+<itemizedlist><listitem><para>Between an enumerator and its item, such as in references:
+<literal>Chapter~12</literal>, or <literal>Theorem~\ref{th:Wilsons}</literal>, or
+<literal>Figure~\ref{fig:KGraph}</literal>. When cases are enumerated inline:
+<literal>(b)~Show that $f(x)$ is (1)~continuous, and (2)~bounded</literal>.
+</para>
+<indexterm role="cp"><primary>package, <literal>siunitx</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>siunitx</literal> package</primary></indexterm>
 
-<para>Some individual commands, notably those defined with the <literal>xspace</literal>,
-package do not follow the standard behavior.
+</listitem><listitem><para>Between a number and its unit: <literal>$745.7.8$~watts</literal> (the
+<filename>siunitx</filename> package has a special facility for this) or
+<literal>144~eggs</literal>. This includes between a month and a date:
+<literal>October~12</literal> or <literal>12~Oct</literal>. In general, in any expressions where
+numbers and abbreviations or symbols are separated by a space:
+<literal>AD~565</literal>, or <literal>2:50~pm</literal>, or <literal>Boeing~747</literal>, or
+<literal>268~Plains Road</literal>, or <literal>\$$1.4$~billion</literal>.
 </para>
+</listitem><listitem><para>When mathematical phrases are rendered in words: <literal>equals~$n$</literal>, or
+<literal>less than~$\epsilon$</literal>, or <literal>given~$X$</literal>, or <literal>modulo~$p^e$
+for all large~$n$</literal> (but compare <literal>is~$15$</literal> with <literal>is $15$~times
+the height</literal>). Between mathematical symbols in apposition with nouns:
+<literal>dimension~$d$</literal> or <literal>function~$f(x)$</literal> (but compare <literal>with
+length $l$~or more</literal>). When a symbol is a tightly bound object of a
+preposition: <literal>of~$x$</literal>, or <literal>from $0$ to~$1$</literal>, or <literal>in
+common with~$m$</literal>.
+</para>
+</listitem><listitem><para>Between symbols in series: <literal>$1$,~$2$, or~$3$</literal> or <literal>$1$,~$2$,
+\ldots,~$n$</literal>.
+</para>
+</listitem><listitem><para>Between a person’s forenames and between multiple surnames:
+<literal>Donald~E. Knuth</literal>, or <literal>Luis~I. Trabb~Pardo</literal>, or
+<literal>Charles~XII</literal> (but you must give TeX places to break the line so
+you may do <literal>Charles Louis Xavier~Joseph de~la Vall\'ee~Poussin</literal>).
+</para>
+</listitem><listitem><para>Before a dash: <literal>pages 12~--14</literal> or <literal>it is~--- it must be
+said~--- plausible</literal>.
+</para>
+</listitem></itemizedlist>
 
 </sect1>
-<sect1 label="19.5" id="_005cthinspace">
-<title><literal>\thinspace</literal>: Insert 1/6em</title>
+<sect1 label="19.8" id="_005cthinspace-_0026-_005cnegthinspace">
+<title><literal>\thinspace</literal> & <literal>\negthinspace</literal></title>
 
 <indexterm role="fn"><primary>\thinspace</primary></indexterm>
+<indexterm role="fn"><primary>\negthinspace</primary></indexterm>
+<indexterm role="cp"><primary>thin space</primary></indexterm>
+<indexterm role="cp"><primary>space, thin</primary></indexterm>
+<indexterm role="cp"><primary>thin space, negative</primary></indexterm>
+<indexterm role="cp"><primary>space, negative thin</primary></indexterm>
 
-<para><literal>\thinspace</literal> produces an unbreakable and unstretchable space that
-is 1/6 of an em.  This is the proper space to use between nested
-quotes, as in ’”.<!-- Abuse @dmn, which is a thin space in Texinfo. -->
+<para>Synopsis, one of:
 </para>
+<screen>\thinspace
+\negthinspace
+</screen>
+<para>Produce an unbreakable and unstretchable space of 1/6em and
+-1/6em.  These are the text mode equivalents of <literal>\,</literal> and
+<literal>\!</literal> (see <link linkend="Spacing-in-math-mode_002f_005cthinspace">Spacing in math mode/\thinspace</link>).  You can use
+<literal>\,</literal> as a synonym for <literal>\thinspace</literal> in text mode.
+</para>
+<para>The <literal>\negthinspace</literal> command is used in text mode mostly for
+fiddling with spaces.  One common use of <literal>\thinspace</literal> is as the
+space between nested quotes.
+</para>
+<screen>Killick replied, ``I heard the Captain say, `Ahoy there.'\thinspace''
+</screen>
+<para>Another use is that some style guides call for a <literal>\thinspace</literal>
+between an ellipsis and a sentence ending period (other style guides,
+though, think the three dots are quite enough already).  Still another
+use is between initials, as in <literal>D.\thinspace E.\ Knuth</literal>.
+</para>
 
 </sect1>
-<sect1 label="19.6" id="_005c_002f">
-<title><literal>\/</literal>: Insert italic correction</title>
+<sect1 label="19.9" id="_005c_002f">
+<title><literal>\/</literal></title>
 
 <indexterm role="fn"><primary>\/</primary></indexterm>
 <indexterm role="cp"><primary>italic correction</primary></indexterm>
 
-<para>The <literal>\/</literal> command produces an <firstterm>italic correction</firstterm>.  This is a
-small space defined by the font designer for a given character,
-to avoid the character colliding with whatever follows.  The italic
-<emphasis>f</emphasis> character typically has a large italic correction value.
+<para>Synopsis:
 </para>
-<para>If the following character is a period or comma, it’s not necessary to
-insert an italic correction, since those punctuation symbols have a
-very small height.  However, with semicolons or colons, as well as
-normal letters, it can help. Compare
-<emphasis>f: f;</emphasis> (in the &tex; output, the ‘f’s are nicely separated)
-with <emphasis>f: f;</emphasis>.
+<screen><replaceable>before-character</replaceable>\/<replaceable>after-character</replaceable>
+</screen>
+<para>Insert an <firstterm>italic correction</firstterm>, a small space defined by the font
+designer for each character, to avoid the character colliding with
+whatever follows. When you use <literal>\/</literal>, &latex; takes the correction
+from the font metric file, scales it by any scaling that has been
+applied to the font, and then inserts that much horizontal space.
 </para>
-<para>When changing fonts with commands such as <literal>\textit{italic
-text}</literal> or <literal>{\itshape italic text}</literal>, &latex; will
-automatically insert an italic correction if appropriate (see <link linkend="Font-styles">Font
-styles</link>).
+<para>Here, were it not for the <literal>\/</literal>, the <replaceable>before-character</replaceable>
+italic f would hit the <replaceable>after-character</replaceable> roman H
 </para>
-<para>Despite the name, roman characters can also have an italic
-correction.  Compare
-pdf&tex; (in the &tex; output, there is a small space after the ‘f’)
-with pdf&tex;.
+<screen>\newcommand{\companylogo}{{\it f}\/H}
+</screen>
+<para>because the italic letter leans far to the right.
 </para>
+<para>If <replaceable>after-character</replaceable> is a period or comma then don’t insert an
+italic correction since those punctuation symbols have a very small
+height.  However, with semicolons or colons as well as with normal
+letters, the italic correction can help.
+</para>
+<para>When you use commands such as <literal>\textit</literal> or <literal>\itshape</literal> to
+change fonts, &latex; will automatically insert any needed italic
+correction (see <link linkend="Font-styles">Font styles</link>).
+</para>
+<para>Roman characters can also have an italic correction.  An example is in
+the name <literal>pdf\/\TeX</literal>.
+</para>
 <para>There is no concept of italic correction in math mode; spacing is done
 in a different way.
 </para>
 
 </sect1>
-<sect1 label="19.7" id="_005chrulefill-_005cdotfill">
-<title><literal>\hrulefill \dotfill</literal></title>
+<sect1 label="19.10" id="_005chrulefill-_0026-_005cdotfill">
+<title><literal>\hrulefill</literal> & <literal>\dotfill</literal></title>
 
 <indexterm role="fn"><primary>\hrulefill</primary></indexterm>
 <indexterm role="fn"><primary>\dotfill</primary></indexterm>
 
-<para>Produce an infinite rubber length (see <link linkend="Lengths">Lengths</link>) filled with a
-horizontal rule (that is, a line) or with dots, instead of just white
-space.
+<para>Synopsis, one of:
 </para>
-<para>When placed between blank lines this example creates a paragraph that is
-left and right justified, where the space in the middle is filled with
-evenly spaced dots.
+<screen>\hrulefill
+\dotfill
+</screen>
+<para>Produce an infinite horizontal rubber length (see <link linkend="Lengths">Lengths</link>) that
+&latex; fills with a rule (that is, a line) or with dots, instead of
+white space.
 </para>
-<screen>\noindent Jack Aubrey\dotfill Melbury Lodge
+<para>This outputs a line 2 inches long.
+</para>
+<screen>Name:~\makebox[2in]{\hrulefill}
 </screen>
+<para>This example, when placed between blank lines, creates a paragraph that
+is left and right justified and where the middle is filled with evenly
+spaced dots.
+</para>
+<screen>\noindent John Aubrey, RN \dotfill{} Melbury Lodge
+</screen>
 <para>To make the rule or dots go to the line’s end use <literal>\null</literal> at the
 start or end.  
 </para>
 <para>To change the rule’s thickness, copy the definition and adjust it, as
-with <literal>\renewcommand{\hrulefill}{\leavevmode\leaders\hrule height
-1pt\hfill\kern\z@}</literal>, which changes the default thickness of
-0.4pt to 1pt.  Similarly, adjust the dot spacing as with
-<literal>\renewcommand{\dotfill}{\leavevmode\cleaders\hb at xt@
-1.00em{\hss .\hss }\hfill\kern\z@}</literal>, which changes the default
-length of 0.33em to 1.00em.
+here
 </para>
-
-</sect1>
-<sect1 label="19.8" id="_005caddvspace">
-<title><literal>\addvspace</literal></title>
-
-<indexterm role="fn"><primary>\addvspace</primary></indexterm>
-<indexterm role="cp"><primary>vertical space</primary></indexterm>
-<indexterm role="cp"><primary>space, inserting vertical</primary></indexterm>
-
-<para><literal>\addvspace{<replaceable>length</replaceable>}</literal>
+<screen>\renewcommand{\hrulefill}{%
+  \leavevmode\leaders\hrule height 1pt\hfill\kern\z@}
+</screen>
+<para>which changes the default thickness of 0.4pt to 1pt.
+Similarly, adjust the dot spacing as with
 </para>
-<para>Add a vertical space of height <replaceable>length</replaceable>, which is a rubber length
-(see <link linkend="Lengths">Lengths</link>).  However, if vertical space has already been added to
-the same point in the output by a previous <literal>\addvspace</literal> command
-then this command will not add more space than what is needed to make
-the natural length of the total vertical space equal to <replaceable>length</replaceable>.
+<screen>\renewcommand{\dotfill}{%
+  \leavevmode\cleaders\hb at xt@1.00em{\hss .\hss }\hfill\kern\z@}
+</screen>
+<para>which changes the default length of 0.33em to 1.00em.
 </para>
-<para>Use this command to adjust the vertical space above or below an
-environment that starts a new paragraph.  For instance, a Theorem
-environment is defined to begin and end with <literal>\addvspace{...}</literal>
-so that two consecutive Theorem’s are separated by one vertical space,
-not two.
+<para>This example produces a line for a signature.
 </para>
-<para>This command is fragile (see <link linkend="_005cprotect">\protect</link>).
+<screen>\begin{minipage}{4cm}
+  \centering
+  \hrulefill\\
+  Signed
+\end{minipage}
+</screen>
+<para>The line is 4cm long.
 </para>
-<para>The error ‘<literal>Something's wrong--perhaps a missing \item</literal>’ means that
-you were not in vertical mode when you invoked this command; one way to
-change that is to precede this command with a <literal>\par</literal> command.
-</para>
 
 </sect1>
-<sect1 label="19.9" id="_005cbigskip-_005cmedskip-_005csmallskip">
-<title><literal>\bigskip \medskip \smallskip</literal></title>
+<sect1 label="19.11" id="_005cbigskip-_0026-_005cmedskip-_0026-_005csmallskip">
+<title><literal>\bigskip</literal> & <literal>\medskip</literal> & <literal>\smallskip</literal></title>
 
-<para>These commands produce a given amount of space, specified by the
-document class.
+<para>Synopsis, one of:
 </para>
-<variablelist><varlistentry><term><indexterm role="fn"><primary>\bigskip</primary></indexterm><literal>\bigskip</literal>
+<screen>\bigskip
+\medskip
+\smallskip
+</screen>
+<para>Produce an amount of vertical space, large or medium-sized or
+small. These commands are fragile (see <link linkend="_005cprotect">\protect</link>).
+</para>
+<para>Here the skip suggests the passage of time (from <emphasis>The Golden Ocean</emphasis> by
+O’Brian).
+</para>
+<screen>Mr Saumarez would have something rude to say to him, no doubt: he
+was at home again, and it was delightful.
+
+\bigskip
+``A hundred and fifty-seven miles and one third, in twenty-four hours,''
+said Peter.
+</screen>
+<para>Each command is associated with a length defined in the document class
+file.
+</para>
+<variablelist><anchor id="bigskip"/><varlistentry><term><indexterm role="fn"><primary>\bigskip</primary></indexterm><literal>\bigskip</literal>
 </term><listitem><indexterm role="fn"><primary>\bigskipamount</primary></indexterm>
 <para>The same as <literal>\vspace{\bigskipamount}</literal>, ordinarily about one line
-space, with stretch and shrink (the default for the <literal>book</literal> and
-<literal>article</literal> classes is <literal>12pt plus 4pt minus 4pt</literal>).
+space, with stretch and shrink.  The default for the <literal>book</literal> and
+<literal>article</literal> classes is <literal>12pt plus 4pt minus 4pt</literal>.
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\medskip</primary></indexterm><literal>\medskip</literal>
+<anchor id="medskip"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\medskip</primary></indexterm><literal>\medskip</literal>
 </term><listitem><indexterm role="fn"><primary>\medskipamount</primary></indexterm>
-<para>The same as <literal>\vspace{\medskipamount}</literal>, ordinarily about half of
-a line space, with stretch and shrink (the default for the <literal>book</literal>
-and <literal>article</literal> classes is <literal>6pt plus 2pt minus 2pt</literal>).
+<para>The same as <literal>\vspace{\medskipamount}</literal>, ordinarily about half of a
+line space, with stretch and shrink.  The default for the <literal>book</literal>
+and <literal>article</literal> classes is <literal>6pt plus 2pt minus 2pt</literal>.
 </para>
-</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\smallskip</primary></indexterm><literal>\smallskip</literal>
+<anchor id="smallskip"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\smallskip</primary></indexterm><literal>\smallskip</literal>
 </term><listitem><indexterm role="fn"><primary>\smallskipamount</primary></indexterm>
 <para>The same as <literal>\vspace{\smallskipamount}</literal>, ordinarily about a
-quarter of a line space, with stretch and shrink (the default for the
-<literal>book</literal> and <literal>article</literal> classes is <literal>3pt plus 1pt minus
-1pt</literal>).
+quarter of a line space, with stretch and shrink.  The default for the
+<literal>book</literal> and <literal>article</literal> classes is <literal>3pt plus 1pt minus 1pt</literal>.
 </para>
 </listitem></varlistentry></variablelist>
+<para>Because each command is a <literal>\vspace</literal>, if you use on in mid-paragraph
+then it will insert its vertical space between the line in which you use
+it and the next line, not necessarily at the place that you use it.  So
+these are best between paragraphs.
+</para>
+<para>The commands <literal>\bigbreak</literal>, <literal>\medbreak</literal>, and <literal>\smallbreak</literal>
+are similar but also suggest to &latex; that this is a good place to
+put a page break (see <link linkend="_005cbigbreak-_0026-_005cmedbreak-_0026-_005csmallbreak">\bigbreak & \medbreak & \smallbreak</link>.
+</para>
 
 </sect1>
-<sect1 label="19.10" id="_005cvfill">
-<title><literal>\vfill</literal></title>
+<sect1 label="19.12" id="_005cbigbreak-_0026-_005cmedbreak-_0026-_005csmallbreak">
+<title><literal>\bigbreak</literal> & <literal>\medbreak</literal> & <literal>\smallbreak</literal></title>
 
-<indexterm role="fn"><primary>\vfill</primary></indexterm>
+<para>Synopsis, one of:
+</para>
+<screen>\bigbreak
+\medbreak
+\smallbreak
+</screen>
+<para>Produce a vertical space that is big or medium-sized or small, and
+suggest to &latex; that this is a good place to break the page.  (The
+associated penalties are -200, -100, and -50.)
+</para>
+<para>See <link linkend="_005cbigskip-_0026-_005cmedskip-_0026-_005csmallskip">\bigskip & \medskip & \smallskip</link>, for more.  These commands
+produce the same vertical space but differ in that they also remove a
+preceding vertical space if it is less than what they would insert (as
+with <literal>\addvspace</literal>).  In addition, they terminate a paragraph where
+they are used: this example
+</para>
+<screen>abc\bigbreak def ghi
 
-<indexterm role="cp"><primary>stretch, infinite vertical</primary></indexterm>
-<indexterm role="cp"><primary>infinite vertical stretch</primary></indexterm>
+jkl mno pqr
+</screen>
+<para>will output three paragraphs, the first ending in ‘<literal>abc</literal>’ and the
+second starting, after an extra vertical space and a paragraph indent,
+with ‘<literal>def</literal>’.
+</para>
 
-<para>End the current paragraph and insert a vertical rubber length
-(see <link linkend="Lengths">Lengths</link>) that is infinite, so it can stretch or shrink as far
-as needed.
+</sect1>
+<sect1 label="19.13" id="_005cstrut">
+<title><literal>\strut</literal></title>
+
+<indexterm role="fn"><primary>\strut</primary></indexterm>
+<indexterm role="cp"><primary>strut</primary></indexterm>
+
+<para>Synopsis:
 </para>
-<para>It is often used in the same way as <literal>\vspace{\fill}</literal>, except that
-<literal>\vfill</literal> ends the current paragraph, whereas
-<literal>\vspace{\fill}</literal> adds the infinite vertical space below its line
-irrespective of the paragraph structure.  In both cases that space will
-disappear at a page boundary; to circumvent this see <link linkend="_005cvspace">\vspace</link>.
+<screen>\strut
+</screen>
+<para>Ensure that the current line has height at least <literal>0.7\baselineskip</literal>
+and depth at least <literal>0.3\baselineskip</literal>.  Essentially, &latex;
+inserts into the line a rectangle having zero width,
+<literal>\rule[-0.3\baselineskip]{0pt}{\baselineskip}</literal> (see <link linkend="_005crule">\rule</link>).
+The <literal>\baselineskip</literal> changes with the current font and fontsize.
 </para>
-<para>In this example the page is filled, so the top and bottom lines contain
-the text ‘<literal>Lost Dog!</literal>’ and the third ‘<literal>Lost Dog!</literal>’ is exactly
-halfway between them.
-</para> 
-<screen>\begin{document}
-Lost Dog!
-\vfill
-Lost Dog!
-\vfill
-Lost Dog!
-\end{document}
+<para>In this example the <literal>\strut</literal> keeps the box inside the frame from
+having zero height.
+</para>
+<screen>\setlength{\fboxsep}{0pt}\framebox[2in]{\strut}
 </screen>
+<para>This example has four lists.  In the first there is a much bigger gap
+between items 2 and 3 than there is between items 1 and 2.
+The second list fixes that with a <literal>\strut</literal> at the end of its first
+item’s second line.
+</para>
+<screen>\setlength{\fboxsep}{0pt}
+\noindent\begin{minipage}[t]{0.2\linewidth}
+\begin{enumerate}
+  \item \parbox[t]{15pt}{test \\ test}
+  \item test
+  \item test
+\end{enumerate}
+\end{minipage}%
+\begin{minipage}[t]{0.2\linewidth}
+\begin{enumerate}
+  \item \parbox[t]{15pt}{test \\ test\strut}
+  \item test
+  \item test
+\end{enumerate}
+\end{minipage}%
+\begin{minipage}[t]{0.2\linewidth}
+\begin{enumerate}
+  \item \fbox{\parbox[t]{15pt}{test \\ test}}
+  \item \fbox{test}
+  \item \fbox{test}
+\end{enumerate}
+\end{minipage}%
+\begin{minipage}[t]{0.2\linewidth}
+\begin{enumerate}
+  \item \fbox{\parbox[t]{15pt}{test \\ test\strut}}
+  \item \fbox{test}
+  \item \fbox{test}
+\end{enumerate}
+\end{minipage}%
+</screen>
+<para>The final two lists use <literal>fbox</literal> to show what’s happening.  The third
+list’s <literal>\parbox</literal> goes only to the bottom of its second ‘<literal>test</literal>’,
+which happens not have any characters that descend below the baseline.
+The fourth list adds the strut that gives the needed extra
+below-baseline space.
+</para>
+<indexterm role="cp"><primary>package, <literal>TikZ</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>TikZ</literal> package</primary></indexterm>
+<indexterm role="cp"><primary>package, <literal>Asymptote</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>Asymptote</literal> package</primary></indexterm>
 
+<para>The <literal>\strut</literal> command is often useful in graphics, such as in
+<filename>TikZ</filename> or <filename>Asymptote</filename>.  For instance, you may have a command
+such as <literal>\graphnode{<replaceable>node-name</replaceable>}</literal> that fits a circle around
+<replaceable>node-name</replaceable>.  However, unless you are careful the <replaceable>node-name</replaceable>’s
+‘<literal>x</literal>’ and ‘<literal>y</literal>’ will produce different-diameter circles because
+the characters are different sizes.  A careful <literal>\graphnode</literal> might
+insert a <literal>\strut</literal>, then <replaceable>node-name</replaceable>, and then draw the circle.
+</para>
+<para>The general approach of using a zero width <literal>\rule</literal> is useful in
+many circumstances.  In this table, the zero-width rule keeps the top of
+the first integral from hitting the <literal>\hline</literal>.  Similarly, the
+second rule keeps the second integral from hitting the first.
+</para>
+<screen>\begin{tabular}{rl}
+  \textsc{Integral}   &\textsc{Value}           \\
+  \hline
+  $\int_0^x t\, dt$   &$x^2/2$  \rule{0em}{2.5ex} \\  
+  $\int_0^x t^2\, dt$ &$x^3/3$  \rule{0em}{2.5ex}
+\end{tabular}
+</screen>
+<para>(Although the line-ending double backslash command has an available
+optional argument to put in more vertical room, that won’t work here.
+Changing the first double backslash to something like <literal>\\[2.5ex]</literal>
+will put the room between the header line and the <literal>\hline</literal>, and the
+integral would still hit the line.)
+</para>
+
 </sect1>
-<sect1 label="19.11" id="_005cvspace">
-<title><literal>\vspace{<replaceable>length</replaceable>}</literal></title>
+<sect1 label="19.14" id="_005cvspace">
+<title><literal>\vspace</literal></title>
 
 <indexterm role="fn"><primary>\vspace</primary></indexterm>
 <indexterm role="cp"><primary>vertical space</primary></indexterm>
 <indexterm role="cp"><primary>space, vertical</primary></indexterm>
 
-<para>Synopsis, one of these two:
+<para>Synopsis, one of:
 </para>
 <screen>\vspace{<replaceable>length</replaceable>}
 \vspace*{<replaceable>length</replaceable>}
 </screen>
-<para>Add the vertical space <replaceable>length</replaceable>.  This can be negative or positive,
-and is a rubber length (see <link linkend="Lengths">Lengths</link>).
+<para>Add the vertical space <replaceable>length</replaceable>.  The <replaceable>length</replaceable> can be positive,
+negative, or zero.  It is a rubber length—it may contain a <literal>plus</literal>
+or <literal>minus</literal> component (see <link linkend="Lengths">Lengths</link>).
 </para>
-<para>&latex; removes the vertical space from <literal>\vspace</literal> at a page
-break, that is, at the top or bottom of a page.  The starred version
-<literal>\vspace*{...}</literal> causes the space to stay.
+<para>This puts space between the two paragraphs.
 </para>
-<para>If <literal>\vspace</literal> is used in the middle of a paragraph (i.e., in
-horizontal mode), the space is inserted <emphasis>after</emphasis> the line with
-the <literal>\vspace</literal> command.  A new paragraph is not started.
+<screen>And I slept.
+
+\vspace{1ex plus 0.5ex}
+The new day dawned cold.
+</screen>
+<para>(See <link linkend="_005cbigskip-_0026-_005cmedskip-_0026-_005csmallskip">\bigskip & \medskip & \smallskip</link> for common inter-paragraph
+spaces.)
 </para>
+<para>The <literal>*</literal>-version inserts vertical space that non-discardable.  More
+precisely, &latex; discards vertical space at a page break and the
+<literal>*</literal>-version causes the space to stay.  This example leaves space
+between the two questions.
+</para>
+<screen>Question: Find the integral of \( 5x^4+5 \).
+
+\vspace*{2cm plus 0.5cm}
+Question: Find the derivative of \( x^5+5x+9 \).
+</screen>
+<para>That space will be present even if the page break happens to fall
+between the questions.
+</para>
+<para>If you use <literal>\vspace</literal> in the middle of a paragraph (i.e., in
+horizontal mode) then the space is inserted after the line containing
+the <literal>\vspace</literal> command; it does not start a new paragraph at the
+<literal>\vspace</literal> command.
+</para>
 <para>In this example the two questions will be evenly spaced vertically on
 the page, with at least one inch of space below each.
 </para>
@@ -9243,222 +12453,548 @@
 </screen>
 
 </sect1>
+<sect1 label="19.15" id="_005cvfill">
+<title><literal>\vfill</literal></title>
+
+<indexterm role="fn"><primary>\vfill</primary></indexterm>
+
+<indexterm role="cp"><primary>stretch, infinite vertical</primary></indexterm>
+<indexterm role="cp"><primary>infinite vertical stretch</primary></indexterm>
+
+<para>Synopsis:
+</para>
+<screen>\vfill
+</screen>
+<para>End the current paragraph and insert a vertical rubber length that is
+infinite, so it can stretch or shrink as far as needed
+(see <link linkend="Lengths">Lengths</link>).
+</para>
+<para>It is often used in the same way as <literal>\vspace{\fill}</literal>, except that
+<literal>\vfill</literal> ends the current paragraph whereas <literal>\vspace{\fill}</literal>
+adds the infinite vertical space below its line, irrespective of the
+paragraph structure.  In both cases that space will disappear at a page
+boundary; to circumvent this see the starred option
+in <link linkend="_005cvspace">\vspace</link>.
+</para>
+<para>In this example the page is filled, so the top and bottom lines contain
+the text ‘<literal>Lost Dog!</literal>’ and the second ‘<literal>Lost Dog!</literal>’ is exactly
+halfway between them.
+</para> 
+<screen>\begin{document}
+Lost Dog!
+\vfill
+Lost Dog!  % perfectly in the middle
+\vfill
+Lost Dog!
+\end{document}
+</screen>
+
+</sect1>
+<sect1 label="19.16" id="_005caddvspace">
+<title><literal>\addvspace</literal></title>
+
+<indexterm role="fn"><primary>\addvspace</primary></indexterm>
+<indexterm role="cp"><primary>vertical space</primary></indexterm>
+<indexterm role="cp"><primary>space, inserting vertical</primary></indexterm>
+
+<para>Synopsis:
+</para>
+<screen>\addvspace{<replaceable>vert-length</replaceable>}
+</screen>
+<para>Add a vertical space of <replaceable>vert-length</replaceable>.  However, if there are two or
+more <literal>\addvspace</literal>’s in a sequence then together they only add the
+space needed to make the natural length equal to the maximum of the
+<replaceable>vert-length</replaceable>’s in that sequence. This command is fragile
+(see <link linkend="_005cprotect">\protect</link>).  The <replaceable>vert-length</replaceable> is a rubber length
+(see <link linkend="Lengths">Lengths</link>).
+</para>
+<para>This example illustrates.  The <literal>picture</literal> draws a scale.  In a
+standard &latex; article the length <literal>\baselineskip</literal> is 12pt.
+The two rules here are 22pt apart: the sum of the
+<literal>\baselineskip</literal> and the 10pt from the first <literal>addvspace</literal>.
+</para>
+<screen>\documentclass{article}
+\usepackage{color}
+\begin{document}
+\setlength{\unitlength}{2pt}%
+\noindent\begin{picture}(0,0)%
+  \multiput(0,0)(0,-1){25}{{\color{blue}\line(1,0){1}}}
+  \multiput(0,0)(0,-5){6}{{\color{red}\line(1,0){2}}}
+\end{picture}%
+\rule{0.25\linewidth}{0.1pt}% 
+\par\addvspace{10pt}% \addvspace{20pt}%
+\par\noindent\rule{0.25\linewidth}{0.1pt}%
+\end{document}
+</screen>
+<para>Now uncomment the second <literal>\addvspace</literal>.  It does not make the gap
+20pt longer; instead the gap is the sum of <literal>\baselineskip</literal>
+and 20pt.  So <literal>\addvspace</literal> in a sense does the opposite of
+its name — it makes sure that multiple vertical spaces do not
+accumulate, but instead that only the largest one is used.
+</para>
+<para>&latex; uses this command to adjust the vertical space above or below
+an environment that starts a new paragraph.  For instance, a
+<literal>theorem</literal> environment begins and ends with <literal>\addvspace</literal> so
+that two consecutive <literal>theorem</literal>’s are separated by one vertical
+space, not two.
+</para>
+<para>A error ‘<literal>Something's wrong--perhaps a missing \item</literal>’ pointing to an
+<literal>\addvspace</literal> means that you were not in vertical mode when you hit
+this command. One way to change that is to precede <literal>\addvspace</literal>
+with a <literal>\par</literal> command (see <link linkend="_005cpar">\par</link>), as in the above example.
+</para>
+
+</sect1>
 </chapter>
 <chapter label="20" id="Boxes">
 <title>Boxes</title>
 
 <indexterm role="cp"><primary>boxes</primary></indexterm>
 
-<para>All the predefined length parameters (see <link linkend="Predefined-lengths">Predefined lengths</link>) can be
-used in the arguments of the box-making commands.
+<para>At its core, &latex; puts things in boxes and then puts the boxes on a
+page.  So these commands are central.
 </para>
+<para>There are many packages on CTAN that are useful for manipulating boxes.
+One useful adjunct to the commands here is <filename>adjustbox</filename>.
+</para>
 
 
-<sect1 label="20.1" id="_005cmbox">
-<title><literal>\mbox{<replaceable>text}</replaceable></literal></title>
+<sect1 label="20.1" id="_005cmbox-_0026-_005cmakebox">
+<title><literal>\mbox</literal> & <literal>\makebox</literal></title>
 
 <indexterm role="fn"><primary>\mbox</primary></indexterm>
+<indexterm role="fn"><primary>\makebox</primary></indexterm>
+<indexterm role="cp"><primary>box</primary></indexterm>
+<indexterm role="cp"><primary>make a box</primary></indexterm>
+<indexterm role="cp"><primary>hyphenation, preventing</primary></indexterm>
 
-<indexterm role="cp"><primary>hyphenation, preventing</primary></indexterm>
-<para>The <literal>\mbox</literal> command creates a box just wide enough to hold the
-text created by its argument.  The <replaceable>text</replaceable> is not broken into
-lines, so it can be used to prevent hyphenation.
+<para>Synopsis, one of:
 </para>
+<screen>\mbox{<replaceable>text</replaceable>}
+\makebox{<replaceable>text</replaceable>}
+\makebox[<replaceable>width</replaceable>]{<replaceable>text</replaceable>}
+\makebox[<replaceable>width</replaceable>][<replaceable>position</replaceable>]{<replaceable>text</replaceable>}
+</screen>
+<para>Create a box, a container for material.  The <replaceable>text</replaceable> is is typeset in
+LR mode (see <link linkend="Modes">Modes</link>) so it is not broken into lines.  The
+<literal>\mbox</literal> command is robust, while <literal>\makebox</literal> is fragile
+(see <link linkend="_005cprotect">\protect</link>).
+</para>
+<para>Because <literal>text</literal> is not broken into lines, you can use <literal>\mbox</literal>
+to prevent hyphenation.  In this example, &latex; will not hyphenate
+the table name, ‘<literal>T-4</literal>’.
+</para>
+<screen>See Table~\mbox{T-4}
+</screen>
+<para>The first two command versions, <literal>\mbox</literal> and <literal>\makebox</literal>, are
+roughly equivalent.  They create a box just wide enough to contain the
+<replaceable>text</replaceable>.  (They are like plain &tex;’s <literal>\hbox</literal>.)
+</para>
+<para>In the third version the optional argument <replaceable>width</replaceable> specifies the
+width of the box.  Note that the space occupied by the text need not
+equal the width of the box.  For one thing, <replaceable>text</replaceable> can be too small;
+this creates a full-line box
+</para>
+<screen>\makebox[\linewidth]{Chapter Exam}
+</screen>
+<para>with ‘<literal>Chapter Exam</literal>’ centered.  But <replaceable>text</replaceable> can also be too wide
+for <replaceable>width</replaceable>.  See the example below of zero-width boxes.
+</para>
+<anchor id="mbox-makebox-depth"/><anchor id="mbox-makebox-height"/><anchor id="mbox-makebox-width"/><anchor id="mbox-makebox-totalheight"/><para>In the <replaceable>width</replaceable> argument you can use the following lengths that refer
+to the dimension of the box that &latex; gets on typesetting
+<replaceable>text</replaceable>: <literal>\depth</literal>, <literal>\height</literal>, <literal>\width</literal>,
+<literal>\totalheight</literal> (this is the box’s height plus its depth).  For
+example, to make a box with the text stretched to double the natural
+size you can say this.
+</para>
+<screen>\makebox[2\width]{Get a stretcher}
+</screen>
+<para>For the fourth command version the optional argument <replaceable>position</replaceable>
+gives position of the text within the box. It may take the following
+values:
+</para>
+<variablelist><varlistentry><term><literal>c</literal>
+</term><listitem><para>The <replaceable>text</replaceable> is centered (default).
+</para>
+</listitem></varlistentry><varlistentry><term><literal>l</literal>
+</term><listitem><para>The <replaceable>text</replaceable> is flush left.
+</para>
+</listitem></varlistentry><varlistentry><term><literal>r</literal>
+</term><listitem><para>Flush right.
+</para>
+</listitem></varlistentry><varlistentry><term><literal>s</literal>
+</term><listitem><para>Stretch the interword space in <replaceable>text</replaceable> across the entire <replaceable>width</replaceable>.
+The <replaceable>text</replaceable> must contain stretchable space for this to work.  For
+instance, this could head a press release:
+<literal>\noindent\makebox[\textwidth][s]{\large\hfil IMMEDIATE\hfil
+RELEASE\hfil}</literal>
+</para></listitem></varlistentry></variablelist>
+<para>A common use of <literal>\makebox</literal> is to make zero-width text boxes.  This
+puts the value of the quiz questions to the left of those questions.
+</para>
+<screen>\newcommand{\pts}[1]{\makebox[0em][r]{#1 points\hspace*{1em}}}
+\pts{10}What is the air-speed velocity of an unladen swallow?
 
+\pts{90}An African or European swallow?
+</screen>
+<para><indexterm role="cp"><primary>package, <literal>TikZ</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>TikZ</literal> package</primary></indexterm>
+</para>
+<indexterm role="cp"><primary>package, <literal>Asymptote</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>Asymptote</literal> package</primary></indexterm>
+
+<para>The right edge of the output ‘<literal>10 points </literal>’ (note the ending space)
+will be just before the ‘<literal>What</literal>’ (note the space after
+‘<literal>points</literal>’).  You can use <literal>\makebox</literal> similarly when making
+graphics, such as in <filename>TikZ</filename> or <filename>Asymptote</filename>, where you put the
+edge of the text at a known location, regardless of the length of that
+text.
+</para>
+<para>For boxes with frames see <link linkend="_005cfbox-_0026-_005cframebox">\fbox & \framebox</link>. For colors
+see <link linkend="Colored-boxes">Colored boxes</link>.
+</para>
+<para>There is a related version of <literal>\makebox</literal> that is used within the
+<literal>picture</literal> environment, where the length is given in terms of
+<literal>\unitlength</literal> (see <link linkend="_005cmakebox-_0028picture_0029">\makebox (picture)</link>).
+</para>
+<para>If you put a double-backslash into <replaceable>text</replaceable> then &latex; will not
+give you a new line; for instance <literal>\makebox{abc def \\ ghi}</literal>
+outputs ‘<literal>abc defghi</literal>’ while <literal>\makebox{abc def \par ghi}</literal>
+outputs ‘<literal>abc def ghi</literal>’, but neither go to a second line.  To get
+multiple lines see <link linkend="_005cparbox">\parbox</link> and <link linkend="minipage">minipage</link>.
+</para>
+
 </sect1>
-<sect1 label="20.2" id="_005cfbox-and-_005cframebox">
-<title><literal>\fbox</literal> and <literal>\framebox</literal></title>
+<sect1 label="20.2" id="_005cfbox-_0026-_005cframebox">
+<title><literal>\fbox</literal> & <literal>\framebox</literal></title>
 
 <indexterm role="fn"><primary>\fbox</primary></indexterm>
 <indexterm role="fn"><primary>\framebox</primary></indexterm>
 
-<para>Synopses:
+<para>Synopses, one of:
 </para>
 <screen>\fbox{<replaceable>text</replaceable>}
+\framebox{<replaceable>text</replaceable>}
+\framebox[<replaceable>width</replaceable>]{<replaceable>text</replaceable>}
 \framebox[<replaceable>width</replaceable>][<replaceable>position</replaceable>]{<replaceable>text</replaceable>}
 </screen>
-<para>The <literal>\fbox</literal> and <literal>\framebox</literal> commands are like <literal>\mbox</literal>,
-except that they put a frame around the outside of the box being created.
+<para>Create a box with an enclosing frame, four lines surrounding the space.
+These commands are the same as <literal>\mbox</literal> and <literal>\makebox</literal> except
+for the frame (see <link linkend="_005cmbox-_0026-_005cmakebox">\mbox & \makebox</link>). The <literal>\fbox</literal> command is
+robust, the <literal>\framebox</literal> command is fragile (see <link linkend="_005cprotect">\protect</link>).
 </para>
-<para>In addition, the <literal>\framebox</literal> command allows for explicit
-specification of the box width with the optional <replaceable>width</replaceable> argument
-(a dimension), and positioning with the optional <replaceable>position</replaceable>
-argument. <!-- xxref -->
+<screen>\fbox{Warning! No work shown, no credit given.}
+</screen>
+<para>&latex; puts the text into a box that cannot be split or hyphenated.
+Around that box, separated from it by a small gap, are four lines making
+a frame.
 </para>
-<indexterm role="fn"><primary>\fboxrule</primary></indexterm>
-<indexterm role="fn"><primary>\fboxsep</primary></indexterm>
-<para>Both commands produce a rule of thickness <literal>\fboxrule</literal> (default
-<literal>0.4pt</literal>), and leave a space of <literal>\fboxsep</literal> (default <literal>3pt</literal>)
-between the rule and the contents of the box.
+<para>The first two command invocations, <literal>\fbox{...}</literal> and
+<literal>\framebox{...}</literal>, are roughly the same.  As to the third and
+fourth invocations, the optional arguments allow you to specify the box
+width as <replaceable>width</replaceable> and the position of the text inside that box as
+<replaceable>position</replaceable>.  See <link linkend="_005cmbox-_0026-_005cmakebox">\mbox & \makebox</link> for the full description but
+here is an example creating an empty box that is 1/4in wide.
 </para>
-<para>See <link linkend="_005cframebox-_0028picture_0029">\framebox (picture)</link>, for the <literal>\framebox</literal> command in the
-<literal>picture</literal> environment.
+<screen>\setlength{\fboxsep}{0pt}\framebox[0.25in]{\strut}}
+</screen>
+<para>The <literal>\strut</literal> inserts a vertical height of <literal>\baselineskip</literal>
+(see <link linkend="_005cstrut">\strut</link>).
 </para>
-
-</sect1>
-<sect1 label="20.3" id="lrbox">
-<title><literal>lrbox</literal></title>
-
-<indexterm role="fn"><primary>lrbox</primary></indexterm>
-
-<para>Synopsis:
+<para>These parameters determine the frame layout.
 </para>
-<screen>\begin{lrbox}{\<replaceable>cmd</replaceable>} 
-  <replaceable>text </replaceable>
-\end{lrbox}
+<variablelist><anchor id="fbox-framebox-fboxrule"/><varlistentry><term><indexterm role="fn"><primary>\fboxrule</primary></indexterm><literal>\fboxrule</literal>
+</term><listitem><indexterm role="fn"><primary>frame, line width</primary></indexterm>
+<indexterm role="fn"><primary>frame rule width</primary></indexterm>
+<indexterm role="cp"><primary>\fboxrule</primary></indexterm>
+<para>The thickness of the lines around the enclosed box.  The default is
+0.2pt.  Change it with a command such as
+<literal>\setlength{\fboxrule}{0.8pt}</literal> (see <link linkend="_005csetlength">\setlength</link>).
+</para>
+<anchor id="fbox-framebox-fboxsep"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\fboxsep</primary></indexterm><literal>\fboxsep</literal>
+</term><listitem><indexterm role="fn"><primary>frame, separation from contents</primary></indexterm>
+<indexterm role="cp"><primary>\fboxsep</primary></indexterm>
+<para>The distance from the frame to the enclosed box. The default is 3pt.
+Change it with a command such as <literal>\setlength{\fboxsep}{0pt}</literal>
+(see <link linkend="_005csetlength">\setlength</link>).  Setting it to 0pt is useful sometimes:
+this will put a frame around the picture with no white border.
+</para>
+<screen>{\setlength{\fboxsep}{0pt}
+ \framebox{%
+   \includegraphics[width=0.5\textwidth]{prudence.jpg}}}
 </screen>
-<para>This is the environment form of <link linkend="_005csbox"><literal>\sbox</literal></link>.
+<para>The extra curly braces keep the effect of the <literal>\setlength</literal> local.
 </para>
-<para>The <replaceable>text</replaceable> inside the environment is saved in the box <literal>\<replaceable>cmd</replaceable></literal>,
-which must have been declared with <literal>\newsavebox</literal>.
+</listitem></varlistentry></variablelist>
+<para>As with <literal>\mbox</literal> and <literal>\makebox</literal>, &latex; will not break lines
+in <replaceable>text</replaceable>.  But this example has &latex; break lines to make a
+paragraph, and then frame the result.
 </para>
-
-</sect1>
-<sect1 label="20.4" id="_005cmakebox">
-<title><literal>\makebox</literal></title>
-
-<indexterm role="fn"><primary>\makebox</primary></indexterm>
-
-<para>Synopsis:
-</para>
-<screen>\makebox[<replaceable>width</replaceable>][<replaceable>position</replaceable>]{<replaceable>text</replaceable>}
+<screen>\framebox{%
+  \begin{minipage}{0.6\linewidth}
+    My dear, here we must run as fast as we can, just to stay in place.
+    And if you wish to go anywhere you must run twice as fast as that.
+  \end{minipage}}
 </screen>
-<para>The <literal>\makebox</literal> command creates a box just wide enough to contain
-the <replaceable>text</replaceable> specified.  The width of the box can be overridden by the
-optional <replaceable>width</replaceable> argument.  The position of the text within the box
-is determined by the optional <replaceable>position</replaceable> argument, which may take
-the following values:
+<para>See <link linkend="Colored-boxes">Colored boxes</link> for colors other than black and white.
 </para>
-<variablelist><varlistentry><term><literal>c</literal>
-</term><listitem><para>Centered (default).
-</para></listitem></varlistentry><varlistentry><term><literal>l</literal>
-</term><listitem><para>Flush left.
-</para></listitem></varlistentry><varlistentry><term><literal>r</literal>
-</term><listitem><para>Flush right.
-</para></listitem></varlistentry><varlistentry><term><literal>s</literal>
-</term><listitem><para>Stretch (justify) across entire <replaceable>width</replaceable>; <replaceable>text</replaceable> must contain
-stretchable space for this to work.
-</para></listitem></varlistentry></variablelist>
-<para><literal>\makebox</literal> is also used within the <literal>picture</literal> environment
-see <link linkend="_005cmakebox-_0028picture_0029">\makebox (picture)</link>.
+<para>The <literal>picture</literal> environment has a version of this command where the
+units depend on <literal>picture</literal>’s <literal>\unitlength</literal> (see <link linkend="_005cframebox-_0028picture_0029">\framebox
+(picture)</link>).
 </para>
 
 </sect1>
-<sect1 label="20.5" id="_005cparbox">
+<sect1 label="20.3" id="_005cparbox">
 <title><literal>\parbox</literal></title>
 
 <indexterm role="fn"><primary>\parbox</primary></indexterm>
+<indexterm role="cp"><primary>paragraph mode</primary></indexterm>
+<indexterm role="cp"><primary>paragraph, in a box</primary></indexterm>
 
-<para>Synopsis:
+<para>Synopses, one of:
 </para>
-<screen>\parbox[<replaceable>position</replaceable>][<replaceable>height</replaceable>][<replaceable>inner-pos</replaceable>]{<replaceable>width</replaceable>}{<replaceable>text</replaceable>}
+<screen>\parbox{<replaceable>width</replaceable>}{<replaceable>contents</replaceable>}
+\parbox[<replaceable>position</replaceable>]{<replaceable>width</replaceable>}{<replaceable>contents</replaceable>}
+\parbox[<replaceable>position</replaceable>][<replaceable>height</replaceable>]{<replaceable>width</replaceable>}{<replaceable>contents</replaceable>}
+\parbox[<replaceable>position</replaceable>][<replaceable>height</replaceable>][<replaceable>inner-pos</replaceable>]{<replaceable>width</replaceable>}{<replaceable>contents</replaceable>}
 </screen>
-<indexterm role="cp"><primary>paragraph mode</primary></indexterm>
-<para>The <literal>\parbox</literal> command produces a box whose contents are created
-in <firstterm>paragraph mode</firstterm>.  It should be used to make a box small
-pieces of text, with nothing fancy inside.  In particular, you
-shouldn’t use any paragraph-making environments inside a
-<literal>\parbox</literal> argument.  For larger pieces of text, including ones
-containing a paragraph-making environment, you should use a
-<literal>minipage</literal> environment (see <link linkend="minipage">minipage</link>).
+<para>Produce a box of text that is <replaceable>width</replaceable> wide. Use this command to make
+a box of small pieces of text, of a single paragraph.  This command is
+fragile (see <link linkend="_005cprotect">\protect</link>).
 </para>
-<para><literal>\parbox</literal> has two mandatory arguments:
+<screen>\begin{picture}(0,0)
+  ...
+  \put(1,2){\parbox{1.75in}{\raggedright Because the graph is a line on
+                         this semilog paper, the relationship is
+                         exponential.}}
+\end{picture}
+</screen>
+<para>The <replaceable>contents</replaceable> are processed in a text mode (see <link linkend="Modes">Modes</link>) so
+&latex; will break lines to make a paragraph.  But it won’t make
+multiple paragraphs; for that, use a <literal>minipage</literal> environment
+(see <link linkend="minipage">minipage</link>).
 </para>
-<variablelist><varlistentry><term><replaceable>width</replaceable>
-</term><listitem><para>the width of the parbox;
-</para></listitem></varlistentry><varlistentry><term><replaceable>text</replaceable>
-</term><listitem><para>the text that goes inside the parbox.
-</para></listitem></varlistentry></variablelist>
-<para>By default &latex; will position vertically a parbox so its center
-lines up with the center of the surrounding text line.  When the
-optional <replaceable>position</replaceable> argument is present and equal either to ‘<literal>t</literal>’
-or ‘<literal>b</literal>’, this allows you respectively to align either the top or
-bottom line in the parbox with the baseline of the surrounding text. You
-may also specify ‘<literal>m</literal>’ for <replaceable>position</replaceable> to get the default
-behaviour.
+<para>The options for <literal>\parbox</literal> (except for <replaceable>contents</replaceable>) are the same
+as those for <literal>minipage</literal>.  For convenience a summary of the options
+is here but see <link linkend="minipage">minipage</link> for a complete description.
 </para>
-<para>The optional <replaceable>height</replaceable> argument overrides the natural height of the box.
+<para>There are two required arguments.  The <replaceable>width</replaceable> is a rigid length
+(see <link linkend="Lengths">Lengths</link>).  It sets the width of the box into which &latex;
+typesets <replaceable>contents</replaceable>.  The <replaceable>contents</replaceable> is the text that is placed
+in that box.  It should not have any paragraph-making components.
 </para>
-<para>The <replaceable>inner-pos</replaceable> argument controls the placement of the text inside
-the box, as follows; if it is not specified, <replaceable>position</replaceable> is used.
+<para>There are three optional arguments, <replaceable>position</replaceable>, <replaceable>height</replaceable>, and
+<replaceable>inner-pos</replaceable>.  The <replaceable>position</replaceable> gives the vertical alignment of the
+<literal>parbox</literal> with respect to the surrounding material.  The possible
+values are <literal>c</literal> or <literal>m</literal> to make the vertical center of the
+<literal>parbox</literal> lines up with the center of the adjacent line (this is the
+default), or <literal>t</literal> to match the top line of the <literal>parbox</literal> with
+the baseline of the surrounding material, or <literal>b</literal> to match the
+bottom line.
 </para>
-<variablelist><varlistentry><term><literal>t</literal>
-</term><listitem><para>text is placed at the top of the box.
-</para></listitem></varlistentry><varlistentry><term><literal>c</literal>
-</term><listitem><para>text is centered in the box.
-</para></listitem></varlistentry><varlistentry><term><literal>b</literal>
-</term><listitem><para>text is placed at the bottom of the box.
-</para></listitem></varlistentry><varlistentry><term><literal>s</literal>
-</term><listitem><para>stretch vertically; the text must contain vertically stretchable space
-for this to work.
-</para></listitem></varlistentry></variablelist>
-
+<para>The optional argument <replaceable>height</replaceable> overrides the natural height of the
+box.
+</para>
+<para>The optional argument <replaceable>inner-pos</replaceable> controls the placement of
+<replaceable>content</replaceable> inside the <literal>parbox</literal>. Its default is the value of
+<replaceable>position</replaceable>.  Its possible values are: <literal>t</literal> to put the
+<replaceable>content</replaceable> at the top of the box, <literal>c</literal> to put it in the vertical
+center, <literal>b</literal> to put it at the bottom of the box, and <literal>s</literal> to
+stretch it out vertically (for this, the text must contain vertically
+stretchable space).
+</para>
 </sect1>
-<sect1 label="20.6" id="_005craisebox">
+<sect1 label="20.4" id="_005craisebox">
 <title><literal>\raisebox</literal></title>
 
 <indexterm role="fn"><primary>\raisebox</primary></indexterm>
 
-<para>Synopsis:
+<para>Synopsis, one of:
 </para>
-<screen>\raisebox{<replaceable>distance</replaceable>}[<replaceable>height</replaceable>][<replaceable>depth</replaceable>]{<replaceable>text</replaceable>}
+<screen>\raisebox{<replaceable>distance</replaceable>}{<replaceable>text</replaceable>}
+\raisebox{<replaceable>distance</replaceable>}[<replaceable>height</replaceable>]{<replaceable>text</replaceable>}
+\raisebox{<replaceable>distance</replaceable>}[<replaceable>height</replaceable>][<replaceable>depth</replaceable>]{<replaceable>text</replaceable>}
 </screen>
-<para>The <literal>\raisebox</literal> command raises or lowers <replaceable>text</replaceable>.  The first
-mandatory argument specifies how high <replaceable>text</replaceable> is to be raised (or
-lowered if it is a negative amount).  <replaceable>text</replaceable> itself is processed
-in LR mode.
+<para>Raise or lower <replaceable>text</replaceable>. This command is fragile (see <link linkend="_005cprotect">\protect</link>).
 </para>
+<para>This example makes a command for the restriction of a function by
+lowering the vertical bar symbol.
+</para>
+<!-- credit: egreg https://tex.stackexchange.com/a/278631/121234 -->
+<screen>\newcommand\restricted[1]{\raisebox{-.5ex}{$|$}_{#1}}
+$f\restricted{A}$
+</screen>
+<para>The first mandatory argument <replaceable>distance</replaceable> specifies how far to raise
+the second mandatory argument <replaceable>text</replaceable>. This is a rigid length
+(see <link linkend="Lengths">Lengths</link>).  If it is negative then it lowers <replaceable>text</replaceable>.  The
+<replaceable>text</replaceable> is processed in LR mode so it cannot contain line breaks
+(see <link linkend="Modes">Modes</link>).
+</para>
 <para>The optional arguments <replaceable>height</replaceable> and <replaceable>depth</replaceable> are dimensions.  If
-they are specified, &latex; treats <replaceable>text</replaceable> as extending a certain
-distance above the baseline (<replaceable>height</replaceable>) or below (<replaceable>depth</replaceable>),
-ignoring its natural height and depth.
+they are specified, they override the natural height and depth of the
+box &latex; gets by typesetting <replaceable>text</replaceable>.
 </para>
+<anchor id="raisebox-depth"/><anchor id="raisebox-height"/><anchor id="raisebox-width"/><anchor id="raisebox-totalheight"/><para>In the arguments <replaceable>distance</replaceable>, <replaceable>height</replaceable>, and <replaceable>depth</replaceable> you can
+use the following lengths that refer to the dimension of the box that
+&latex; gets on typesetting <replaceable>text</replaceable>: <literal>\depth</literal>, <literal>\height</literal>,
+<literal>\width</literal>, <literal>\totalheight</literal> (this is the box’s height plus its
+depth).
+</para>
+<para>This will align two graphics on their top (see <link linkend="Graphics">Graphics</link>).
+</para>
+<!-- credit: FAQ https://texfaq.org/FAQ-topgraph -->
+<screen>\usepackage{graphicx} \usepackage{calc}  % in preamble
+   ...
+\begin{center}
+  \raisebox{1ex-\height}{%
+    \includegraphics[width=0.4\linewidth]{lion.png}}
+  \qquad
+  \raisebox{1ex-\height}{%
+    \includegraphics[width=0.4\linewidth]{meta.png}}
+\end{center}
+</screen>
+<para>The first <literal>\height</literal> is the height of <filename>lion.png</filename> while the
+second is the height of <filename>meta.png</filename>.
+</para>
 
 </sect1>
-<sect1 label="20.7" id="_005csavebox">
-<title><literal>\savebox</literal></title>
+<sect1 label="20.5" id="_005csbox-_0026-_005csavebox">
+<title><literal>\sbox</literal> & <literal>\savebox</literal></title>
 
+<indexterm role="fn"><primary>\sbox</primary></indexterm>
 <indexterm role="fn"><primary>\savebox</primary></indexterm>
+<indexterm role="cp"><primary>box, save</primary></indexterm>
 
-<para>Synopsis:
+<para>Synopsis, one of:
 </para>
-<screen>\savebox{<replaceable>\boxcmd</replaceable>}[<replaceable>width</replaceable>][<replaceable>pos</replaceable>]{<replaceable>text</replaceable>}
+<screen>\sbox{<replaceable>box-cmd</replaceable>}{<replaceable>text</replaceable>}
+\savebox{<replaceable>box-cmd</replaceable>}{<replaceable>text</replaceable>}
+\savebox{<replaceable>box-cmd</replaceable>}[<replaceable>width</replaceable>]{<replaceable>text</replaceable>}
+\savebox{<replaceable>box-cmd</replaceable>}[<replaceable>width</replaceable>][<replaceable>pos</replaceable>]{<replaceable>text</replaceable>}
 </screen>
-<para>This command typeset <replaceable>text</replaceable> in a box just as with <literal>\makebox</literal>
-(see <link linkend="_005cmakebox">\makebox</link>), except that instead of printing the resulting box,
-it saves it in the box labeled <replaceable>\boxcmd</replaceable>, which must have been
-declared with <literal>\newsavebox</literal> (see <link linkend="_005cnewsavebox">\newsavebox</link>).
+<para>Typeset <replaceable>text</replaceable> just as with <literal>\makebox</literal> (see <link linkend="_005cmbox-_0026-_005cmakebox">\mbox &
+\makebox</link>) except that &latex; does not output it but instead saves it
+in a storage bin named <replaceable>box-cmd</replaceable>.  The bin name <replaceable>box-cmd</replaceable> begins
+with a backslash, <literal>\</literal>.  You must have previously allocated the bin
+<replaceable>box-cmd</replaceable> with <literal>\newsavebox</literal> (see <link linkend="_005cnewsavebox">\newsavebox</link>).The
+<literal>\sbox</literal> command is robust while <literal>\savebox</literal> is fragile
+(see <link linkend="_005cprotect">\protect</link>).
 </para>
+<para>This creates and uses a bin.
+</para>
+<screen>\newsavebox{\fullname}
+\sbox{\fullname}{John Jacob Jingleheimer Schmidt}
+  ...
+\usebox{\fullname}! His name is my name, too!
+Whenever we go out, the people always shout!
+There goes \\usebox{\fullname}!  Ya da da da da da da.
+</screen>
+<para>One advantage of using and reusing a bin over a <literal>\newcommand</literal> is
+efficiency, that &latex; need not repeatedly retypeset the contents.
+See the example below.
+</para>
+<para>The first two command invocations,
+<literal>\sbox{<replaceable>box-cmd</replaceable>}{<replaceable>text</replaceable>}</literal> and
+<literal>\savebox{<replaceable>box-cmd</replaceable>}{<replaceable>text</replaceable>}</literal>, are roughly equivalent.
+As to the third and fourth, the optional arguments allow you to specify
+the box width as <replaceable>width</replaceable>, and the position of the text inside that
+box as <replaceable>position</replaceable>.  See <link linkend="_005cmbox-_0026-_005cmakebox">\mbox & \makebox</link> for the full
+description.
+</para>
+<para>In the <literal>\sbox</literal> and <literal>\savebox</literal> commands the <replaceable>text</replaceable> is
+typeset in LR mode so it does not have line breaks (see <link linkend="Modes">Modes</link>).  If
+you use these then &latex; doesn’t give you an error but it ignores
+what you want: if you enter <literal>\sbox{\newbin}{test \\ test}</literal> and
+<literal>\usebox{\newbin}</literal> then you get ‘<literal>testtest</literal>’, while if you
+enter <literal>\sbox{\newbin}{test \par test}</literal> and
+<literal>\usebox{\newbin}</literal> then you get ‘<literal>test test</literal>’, but no error or
+warning.  To fix this use a <literal>\parbox</literal> or <literal>minipage</literal> as here.
+</para>
+<!-- credit: egreg https://tex.stackexchange.com/a/41668/121234 -->
+<screen>\savebox{\abin}{%
+  \begin{minipage}{\linewidth}
+    \begin{enumerate}
+      \item First item
+      \item Second item
+    \end{enumerate}
+  \end{minipage}}
+  ...
+\usebox{\abin}
+</screen>
+<para>As an example of the efficiency of reusing a bin’s contents, this puts
+the same picture on each page of the document by putting it in the
+header.  &latex; only typesets it once.
+</para>
+<screen>\usepackage{graphicx}  % all this in the preamble
+\newsavebox{\sealbin}
+\savebox{\sealbin}{%
+  \setlength{\unitlength}{1in}%
+  \begin{picture}(0,0)%
+     \put(1.5,-2.5){%
+       \begin{tabular}{c}
+          \includegraphics[height=2in]{companylogo.png} \\
+          Office of the President
+       \end{tabular}}
+  \end{picture}%
+}
+\markright{\usebox{\sealbin}}
+\pagestyle{headings}
+</screen>
+<para>The <literal>picture</literal> environment is good for fine-tuning the placement.
+</para>
+<para>If the bin has not already been defined then you get something like
+‘<literal>Undefined control sequence. <argument> \nobin</literal>’.
+</para>
 
 </sect1>
-<sect1 label="20.8" id="_005csbox">
-<title><literal>\sbox{<replaceable>\boxcmd</replaceable>}{<replaceable>text</replaceable>}</literal></title>
+<sect1 label="20.6" id="lrbox">
+<title><literal>lrbox</literal></title>
 
-<indexterm role="fn"><primary>\sbox</primary></indexterm>
+<indexterm role="fn"><primary>lrbox</primary></indexterm>
 
 <para>Synopsis:
 </para>
-<screen>\sbox{<replaceable>\boxcmd</replaceable>}{<replaceable>text</replaceable>}
+<screen>\begin{lrbox}{<replaceable>box-cmd</replaceable>} 
+  <replaceable>text</replaceable>
+\end{lrbox}
 </screen>
-<para><literal>\sbox</literal> types <replaceable>text</replaceable> in a box just as with <literal>\mbox</literal>
-(see <link linkend="_005cmbox">\mbox</link>) except that instead of the resulting box being
-included in the normal output, it is saved in the box labeled
-<replaceable>\boxcmd</replaceable>.  <replaceable>\boxcmd</replaceable> must have been previously declared with
-<literal>\newsavebox</literal> (see <link linkend="_005cnewsavebox">\newsavebox</link>).
+<para>The <replaceable>text</replaceable> inside the environment is saved in the bin
+<literal><replaceable>box-cmd</replaceable></literal>.  The <replaceable>box-cmd</replaceable> must begin with a
+backslash. You must create this bin in advance with <literal>\newsavebox</literal>
+(see <link linkend="_005cnewsavebox">\newsavebox</link>).  This is the environment form of the <literal>\sbox</literal>
+and <literal>\savebox</literal> commands, and is equivalent to them. See <link linkend="_005csbox-_0026-_005csavebox">\sbox &
+\savebox</link> for the full information.
 </para>
+<para>In this example the environment is convenient for entering the
+<literal>tabular</literal>.
+</para>
+<screen>\newsavebox{\jhbin}
+\begin{lrbox}{\jhbin}
+  \begin{tabular}{c}
+    \includegraphics[height=1in]{jh.png} \\
+    Jim Hef{}feron
+  \end{tabular}
+\end{lrbox}    
+  ...
+\usebox{\jhbin}
+</screen>
 
 </sect1>
-<sect1 label="20.9" id="_005cusebox">
-<title><literal>\usebox{<replaceable>\boxcmd</replaceable>}</literal></title>
+<sect1 label="20.7" id="_005cusebox">
+<title><literal>\usebox</literal></title>
 
 <indexterm role="fn"><primary>\usebox</primary></indexterm>
+<indexterm role="cp"><primary>box, use saved box</primary></indexterm>
 
 <para>Synopsis:
 </para>
-<screen>\usebox{<replaceable>\boxcmd</replaceable>}
+<screen>\usebox{<replaceable>box-cmd</replaceable>}
 </screen>
-<para><literal>\usebox</literal> produces the box most recently saved in the bin
-<replaceable>\boxcmd</replaceable> by a <literal>\savebox</literal> command (see <link linkend="_005csavebox">\savebox</link>).
+<para>Produce the box most recently saved in the bin <replaceable>box-cmd</replaceable> by the
+commands <literal>\sbox</literal> or <literal>\savebox</literal>, or the <literal>lrbox</literal>
+environment. See <link linkend="_005csbox-_0026-_005csavebox">\sbox & \savebox</link> for more information and examples.
+(Note that <replaceable>box-cmd</replaceable> starts with a backslash.)  This command is
+robust (see <link linkend="_005cprotect">\protect</link>).
 </para>
 
 </sect1>
@@ -9483,7 +13019,7 @@
 
 
 <sect1 label="21.1" id="Color-package-options">
-<title>Color package options</title>
+<title><literal>color</literal> package options</title>
 
 <indexterm role="cp"><primary>color package options</primary></indexterm>
 <indexterm role="cp"><primary>options, color package</primary></indexterm>
@@ -9547,25 +13083,25 @@
 such as with inks, so that combining full intensity of cyan, magenta,
 and yellow makes black.
 </para>
-<variablelist><varlistentry><term><literal>cmyk</literal>
+<variablelist><anchor id="color-models-cmyk"/><varlistentry><term><literal>cmyk</literal>
 </term><listitem><para>A comma-separated list with four real numbers between 0 and 1,
 inclusive.  The first number is the intensity of cyan, the second is
 magenta, and the others are yellow and black.  A number value of 0 means
 minimal intensity, while a 1 is for full intensity.  This model is often
 used in color printing.  It is a subtractive model.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>gray</literal>
+<anchor id="color-models-gray"/></listitem></varlistentry><varlistentry><term><literal>gray</literal>
 </term><listitem><para>A single real number between 0 and 1, inclusive.  The colors are shades
 of grey.  The number 0 produces black while 1 gives white.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>rgb</literal>
+<anchor id="color-models-rgb"/></listitem></varlistentry><varlistentry><term><literal>rgb</literal>
 </term><listitem><para>A comma-separated list with three real numbers between 0 and 1,
 inclusive.  The first number is the intensity of the red component, the
 second is green, and the third the blue.  A number value of 0 means that
 none of that component is added in, while a 1 means full intensity.
 This is an additive model.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>RGB</literal>
+<anchor id="color-models-RGB"/></listitem></varlistentry><varlistentry><term><literal>RGB</literal>
 </term><listitem><para>(<filename>pdftex</filename>, <filename>xetex</filename>, <filename>luatex</filename> drivers) A comma-separated
 list with three integers between 0 and 255, inclusive.  This model is a
 convenience for using <literal>rgb</literal> since outside of &latex; colors are
@@ -9573,7 +13109,7 @@
 The values entered here are converted to the <literal>rgb</literal> model by
 dividing by 255.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>named</literal>
+<anchor id="color-models-named"/></listitem></varlistentry><varlistentry><term><literal>named</literal>
 </term><listitem><para>Colors are accessed by name, such as ‘<literal>PrussianBlue</literal>’.  The list of
 names depends on the driver, but all support the names ‘<literal>black</literal>’,
 ‘<literal>blue</literal>’, ‘<literal>cyan</literal>’, ‘<literal>green</literal>’, ‘<literal>magenta</literal>’, ‘<literal>red</literal>’,
@@ -9603,10 +13139,13 @@
 </para>
 <screen>\definecolor{<replaceable>name</replaceable>}{<replaceable>model</replaceable>}{<replaceable>specification</replaceable>}
 </screen>
-<para>Give the name <replaceable>name</replaceable> to the color.  For example, after
-<literal>\definecolor{silver}{rgb}{0.75,0.75,0.74}</literal> you can use that
-color name with <literal>Hi ho, \textcolor{silver}{Silver}!</literal>.
+<para>Give the name <replaceable>name</replaceable> to the color.  For example, after this
 </para>
+<screen>\definecolor{silver}{rgb}{0.75,0.75,0.74}
+</screen>
+<para>you can use that color name with <literal>Hi ho,
+\textcolor{silver}{Silver}!</literal>.
+</para>
 <para>This example gives the color a more abstract name, so it could change and
 not be misleading.
 </para>
@@ -9636,7 +13175,8 @@
 </screen>
 <para>The affected text gets the color.  This line
 </para>
-<screen>\textcolor{magenta}{My name is Ozymandias, king of kings:} Look on my works, ye Mighty, and despair!
+<screen>\textcolor{magenta}{My name is Ozymandias, king of kings:}
+Look on my works, ye Mighty, and despair!
 </screen>
 <para>causes the first half to be in magenta while the rest is in black.  You
 can use a color declared with <literal>\definecolor</literal> in exactly the same
@@ -9661,10 +13201,13 @@
   \end{tabular}
 \end{center}
 </screen>
-<para>You can use color in equations.  A document might have
-<literal>\definecolor{highlightcolor}{RGB}{225,15,0}</literal> in the
-preamble, and then contain this equation.
+<para>You can use color in equations.  A document might have this definition
+in the preamble
 </para>
+<screen>\definecolor{highlightcolor}{RGB}{225,15,0}
+</screen>
+<para>and then contain this equation.
+</para>
 <screen>\begin{equation}
   \int_a^b \textcolor{highlightcolor}{f'(x)}\,dx=f(b)-f(a)
 \end{equation}
@@ -9673,7 +13216,8 @@
 but sometimes you want a one-off.  Those are the second forms in the
 synopses.
 </para>
-<screen>Colors of \textcolor[rgb]{0.33,0.14,0.47}{Purple} and {\color[rgb]{0.72,0.60,0.37} Gold} for the team
+<screen>Colors of \textcolor[rgb]{0.33,0.14,0.47}{Purple} and
+{\color[rgb]{0.72,0.60,0.37} Gold} for the team.
 </screen>
 <para>The format of <replaceable>color specification </replaceable> depends on the color model
 (see <link linkend="Color-models">Color models</link>).  For instance, while <literal>rgb</literal> takes three
@@ -9701,12 +13245,12 @@
 <para>Synopses:
 </para>
 <screen>\colorbox{<replaceable>name</replaceable>}{...}
-\colorbox[<replaceable>model name</replaceable>]{<replaceable>box background color specification</replaceable>}{...}
+\colorbox[<replaceable>model name</replaceable>]{<replaceable>box background color</replaceable>}{...}
 </screen>
 <para>or
 </para>
 <screen>\fcolorbox{<replaceable>frame color</replaceable>}{<replaceable>box background color</replaceable>}{...}
-\fcolorbox[<replaceable>model name</replaceable>]{<replaceable>frame color specification</replaceable>}{<replaceable>box background color specification</replaceable>}{...}
+\fcolorbox[<replaceable>model name</replaceable>]{<replaceable>frame color</replaceable>}{<replaceable>box background color</replaceable>}{...}
 </screen>
 <para>Make a box with the stated background color.  The <literal>\fcolorbox</literal>
 command puts a frame around the box.  For instance this
@@ -9721,7 +13265,7 @@
 <screen>\colorbox{blue}{\textcolor{white}{Welcome to the machine.}}
 </screen>
 <para>The <literal>\fcolorbox</literal> commands use the same parameters as <literal>\fbox</literal>
-(see <link linkend="_005cfbox-and-_005cframebox">\fbox and \framebox</link>), <literal>\fboxrule</literal> and <literal>\fboxsep</literal>, to
+(see <link linkend="_005cfbox-_0026-_005cframebox">\fbox & \framebox</link>), <literal>\fboxrule</literal> and <literal>\fboxsep</literal>, to
 set the thickness of the rule and the boundary between the box interior
 and the surrounding rule.  &latex;’s defaults are <literal>0.4pt</literal> and
 <literal>3pt</literal>, respectively.
@@ -9804,12 +13348,12 @@
 commands of this chapter.  Two that use a programming language are
 Asymptote and MetaPost.  One that uses a graphical interface is Xfig.
 Full description of these systems is outside the scope of this document;
-see their documentation.
+see their documentation on CTAN.
 </para>
 
 
 <sect1 label="22.1" id="Graphics-package-options">
-<title>Graphics package options</title>
+<title><literal>graphics</literal> package options</title>
 
 <indexterm role="cp"><primary>graphics package options</primary></indexterm>
 <indexterm role="cp"><primary>options, graphics package</primary></indexterm>
@@ -9883,7 +13427,7 @@
 
 </sect1>
 <sect1 label="22.2" id="Graphics-package-configuration">
-<title>Graphics package configuration</title>
+<title><literal>graphics</literal> package configuration</title>
 
 <indexterm role="cp"><primary>graphics</primary></indexterm>
 <indexterm role="cp"><primary>graphics package</primary></indexterm>
@@ -9898,7 +13442,7 @@
 the graphic.
 </para>
 <para>The behavior of file system search code is necessarily platform
-dependent.  In this document we cover Linux, Macintosh, and Windows, as
+dependent.  In this document we cover GNU/Linux, Macintosh, and Windows, as
 those systems are typically configured.  For other situations consult
 the documentation in <filename>grfguide.pdf</filename>, or the &latex; source, or your
 &tex; distribution’s documentation.
@@ -9962,9 +13506,9 @@
 portability by adjusting your &tex; system settings configuration file
 parameter <literal>TEXINPUTS</literal>; see the documentation of your system.)
 </para>
-<para>You can use <literal>\graphicspath</literal> in the preamble or in the document
-body.  You can use it more than once.  For debugging, show its value
-with <literal>\makeatletter\typeout{\Ginput at path}\makeatother</literal>.
+<para>You can use <literal>\graphicspath</literal> anywhere in the document.  You can use
+it more than once.  Show its value with
+<literal>\makeatletter\typeout{\Ginput at path}\makeatother</literal>.
 </para>
 <para>The directories are taken with respect to the base file.  That is,
 suppose that you are working on a document based on <filename>book/book.tex</filename>
@@ -10004,17 +13548,18 @@
 not found</literal>’.  Note that you must include the periods at the start of the
 extensions.
 </para>
-<para>Because Linux and Macintosh filenames are case sensitive, the list of
+<para>Because GNU/Linux and Macintosh filenames are case sensitive, the list of
 file extensions is case sensitive on those platforms.  The Windows
 platform is not case sensitive.
 </para>
 <para>You are not required to include <literal>\DeclareGraphicsExtensions</literal> in
 your document; the printer driver has a sensible default.  For example,
-the most recent <filename>pdftex.def</filename> has the extension list
-‘<literal><literal>.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPEG,.JBIG2,.JB2</literal></literal>’.
+the most recent <filename>pdftex.def</filename> has this extension list.
 </para>
-<para>You can use this command in the preamble or in the document body.  You
-can use it more than once.  For debugging, show its value with
+<screen>.png,.pdf,.jpg,.mps,.jpeg,.jbig2,.jb2,.PNG,.PDF,.JPG,.JPEG,.JBIG2,.JB2
+</screen>
+<para>You can use this command anywhere in the document.  You can use it more
+than once.  Show its value with
 <literal>\makeatletter\typeout{\Gin at extensions}\makeatother</literal>.
 </para>
 
@@ -10155,8 +13700,8 @@
 as with <literal>\includegraphics{graphics/plot.pdf}</literal>.  To specify a list
 of locations to search for the file, see <link linkend="_005cgraphicspath">\graphicspath</link>.
 </para>
-<para>If your filename includes spaces then put it in double quotes, as with
-<literal>\includegraphics{"sister picture.jpg"}</literal>.
+<para>If your filename includes spaces then put it in double quotes. An example
+is <literal>\includegraphics{"sister picture.jpg"}</literal>.
 </para>
 <para>The <literal>\includegraphics{<replaceable>filename</replaceable>}</literal> command decides on the
 type of graphic by splitting <replaceable>filename</replaceable> on the first dot.  You can
@@ -10191,14 +13736,13 @@
   ...
 \begin{center}
   \includegraphics{pix/nix.png}
-  \captionof{figure}{The spirit of the night} \label{pix:nix}  % if you want a caption  
+  \captionof{figure}{The spirit of the night} \label{pix:nix} % optional
 \end{center}
 </screen>
 <para>This example puts a box with a graphic side by side with one having
 text, with the two vertically centered.
 </para>
-<screen>\newcommand*{\vcenteredhbox}[1]{\begingroup
-                                \setbox0=\hbox{#1}\parbox{\wd0}{\box0}\endgroup}
+<screen>\newcommand*{\vcenteredhbox}[1]{\begin{tabular}{@{}c@{}}#1\end{tabular}}
   ...
 \begin{center}
   \vcenteredhbox{\includegraphics[width=0.4\textwidth]{plot}}
@@ -10246,7 +13790,7 @@
 page it puts together boxes and this is the box allocated for the
 graphic.
 </para>
-<variablelist><varlistentry><term><literal>width</literal>
+<variablelist><anchor id="includegraphics-width"/><varlistentry><term><literal>width</literal>
 </term><listitem><para>The graphic will be shown so its bounding box is this width.  An example
 is <literal>\includegraphics[width=1in]{plot}</literal>.  You can use the standard
 &tex; dimensions (see <link linkend="Units-of-length">Units of length</link>) and also convenient is
@@ -10257,37 +13801,38 @@
 <literal>\includegraphics[width=\linewidth-1.0cm]{hefferon.jpg}</literal>.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>height</literal>
-</term><listitem><para>The graphic will be shown so its bounding box is this height.  You can
+</term><listitem><anchor id="includegraphics-height"/><para>The graphic will be shown so its bounding box is this height.  You can
 use the standard &tex; dimensions (see <link linkend="Units-of-length">Units of length</link>), and also
 convenient are <literal>\pageheight</literal> and <literal>\textheight</literal> (see <link linkend="Page-layout-parameters">Page
-layout parameters</link>).  For instance,
+layout parameters</link>).  For instance, the command
 <literal>\includegraphics[height=0.25\textheight]{godel}</literal> will make the
-graphic be a quarter of the height of the text area.
+graphic a quarter of the height of the text area.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>totalheight</literal>
-</term><listitem><para>The graphic will be shown so its bounding box has this height plus
+</term><listitem><anchor id="includegraphics-totalheght"/><para>The graphic will be shown so its bounding box has this height plus
 depth.  This differs from the height if the graphic was rotated. For
 instance, if it has been rotated by -90 then it will have zero height
 but a large depth.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>keepaspectratio</literal>
-</term><listitem><para>If set to <literal>true</literal>, or just specified as with
-<literal>\includegraphics[...,keepaspectratio,...]{...}</literal> and you give as
-options both <literal>width</literal> and <literal>height</literal> (or <literal>totalheight</literal>),
-then &latex; will make the graphic is as large as possible without
-distortion. That is, &latex; will ensure that neither is the graphic
-wider than <literal>width</literal> nor taller than <literal>height</literal> (or
+</term><listitem><anchor id="includegraphics-keepaspectratio"/><para>If set to <literal>true</literal>, or just specified as here
+</para>
+<screen><literal>\includegraphics[...,keepaspectratio,...]{...}</literal>
+</screen>
+<para>and you give as options both <literal>width</literal> and <literal>height</literal> (or
+<literal>totalheight</literal>), then &latex; will make the graphic is as large as
+possible without distortion. That is, &latex; will ensure that neither
+is the graphic wider than <literal>width</literal> nor taller than <literal>height</literal> (or
 <literal>totalheight</literal>).
 </para>
 </listitem></varlistentry><varlistentry><term><literal>scale</literal>
-</term><listitem><para>Factor by which to scale the graphic.  Specifying
-<literal>\includegraphics[scale=2.0]{...}</literal> makes the graphic twice its
-nominal size.  This number may be any value; a number between 1
-and 0 will shrink the graphic and a negative number will reflect
-it.
+</term><listitem><para>Factor by which to scale the graphic.  To make a graphic twice its
+nominal size, enter <literal>\includegraphics[scale=2.0]{...}</literal>.  This
+number may be any value; a number between 1 and 0 will shrink the
+graphic and a negative number will reflect it.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>angle</literal>
-</term><listitem><para>Rotate the picture.  The angle is taken in degrees and counterclockwise.
+</term><listitem><para>Rotate the graphic.  The angle is taken in degrees and counterclockwise.
 The graphic is rotated about its <literal>origin</literal>; see that option.  For a
 complete description of how rotated material is typeset,
 see <link linkend="_005crotatebox">\rotatebox</link>.
@@ -10296,9 +13841,9 @@
 </term><listitem><para>The point of the graphic about which the rotation happens.  Possible
 values are any string containing one or two of: <literal>l</literal> for left,
 <literal>r</literal> for right, <literal>b</literal> for bottom, <literal>c</literal> for center, <literal>t</literal>
-for top, and <literal>B</literal> for baseline.  Thus,
+for top, and <literal>B</literal> for baseline.  Thus, entering the command
 <literal>\includegraphics[angle=180,origin=c]{moon}</literal> will turn the
-picture upside down from the center, while
+picture upside down about that picture’s center, while the command
 <literal>\includegraphics[angle=180,origin=lB]{LeBateau}</literal> will turn its
 picture upside down about its left baseline.  (The character <literal>c</literal>
 gives the horizontal center in <literal>bc</literal> or <literal>tc</literal>, but gives the
@@ -10309,7 +13854,7 @@
 </listitem></varlistentry></variablelist>
 <para>These are lesser-used options.
 </para>
-<variablelist><varlistentry><term><literal>viewport</literal>
+<variablelist><anchor id="includegraphics-viewport"/><varlistentry><term><literal>viewport</literal>
 </term><listitem><para>Pick out a subregion of the graphic to show.  Takes four arguments,
 separated by spaces and given in &tex; dimensions, as with
 <literal>\includegraphics[.., viewport=0in 0in 1in 0.618in]{...}</literal>.  The
@@ -10317,7 +13862,7 @@
 relative to the origin specified by the bounding box.  See also the
 <literal>trim</literal> option.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>trim</literal>
+<anchor id="includegraphics-trim"/></listitem></varlistentry><varlistentry><term><literal>trim</literal>
 </term><listitem><para>Gives parts of the graphic to not show.  Takes four arguments, separated
 by spaces, that are given in &tex; dimensions, as with
 <literal>\includegraphics[.., trim= 0in 0.1in 0.2in 0.3in, ...]{...}</literal>.
@@ -10326,18 +13871,20 @@
 the bottom, 0.2 inches on the right, and 0.3 inches on the
 top.  See also the <literal>viewport</literal> option.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>clip</literal>
-</term><listitem><para>If set to <literal>true</literal>, or just specified as with
-<literal>\includegraphics[...,clip,...]{...}</literal>, then the graphic is
-cropped to the bounding box.  You can get this effect by instead using
-the starred form of the command, as
+<anchor id="includegraphics-clip"/></listitem></varlistentry><varlistentry><term><literal>clip</literal>
+</term><listitem><para>If set to <literal>true</literal>, or just specified as here
+</para>
+<screen>\includegraphics[...,clip,...]{...}
+</screen>
+<para>then the graphic is cropped to the bounding box.  This is the same as
+using the starred form of the command,
 <literal>\includegraphics*[...]{...}</literal>.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>page</literal>
+<anchor id="includegraphics-page"/></listitem></varlistentry><varlistentry><term><literal>page</literal>
 </term><listitem><para>Give the page number of a multi-page PDF file.  The default is
 <literal>page=1</literal>.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>pagebox</literal>
+<anchor id="includegraphics-pagebox"/></listitem></varlistentry><varlistentry><term><literal>pagebox</literal>
 </term><listitem><para>Specifies which bounding box to use for PDF files from among
 <literal>mediabox</literal>, <literal>cropbox</literal>, <literal>bleedbox</literal>, <literal>trimbox</literal>, or
 <literal>artbox</literal>.  PDF files do not have the BoundingBox that PostScript
@@ -10351,23 +13898,26 @@
 present, otherwise it will not use one of the others, with a
 driver-defined order of preference.  MediaBox is always present.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>interpolate</literal>
+<anchor id="includegraphics-interpolate"/></listitem></varlistentry><varlistentry><term><literal>interpolate</literal>
 </term><listitem><para>Enable or disable interpolation of raster images by the viewer.  Can be
-set with <literal>interpolate=true</literal> or just specified as with
-<literal>\includegraphics[...,interpolate,...]{...}</literal>.
+set with <literal>interpolate=true</literal> or just specified as here.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>quiet</literal>
+<screen>\includegraphics[...,interpolate,...]{...}
+</screen>
+<anchor id="includegraphics-quiet"/></listitem></varlistentry><varlistentry><term><literal>quiet</literal>
 </term><listitem><para>Do not write information to the log.  You can set it with
 <literal>quiet=true</literal> or just specified it with
 <literal>\includegraphics[...,quite,...]{...}</literal>,
 </para>
-</listitem></varlistentry><varlistentry><term><literal>draft</literal>
-</term><listitem><para>If you set it with <literal>draft=true</literal> or just specified it with
-<literal>\includegraphics[...,draft,...]{...}</literal>, then the graphic will not
-appear in the document, possibly saving color printer ink.  Instead,
-&latex; will put an empty box of the correct size with the filename
-printed in it.
+<anchor id="includegraphics-draft"/></listitem></varlistentry><varlistentry><term><literal>draft</literal>
+</term><listitem><para>If you set it with <literal>draft=true</literal> or just specify it with
 </para>
+<screen>\includegraphics[...,draft,...]{...}
+</screen>
+<para>then the graphic will not appear in the document, possibly saving color
+printer ink.  Instead, &latex; will put an empty box of the correct
+size with the filename printed in it.
+</para>
 </listitem></varlistentry></variablelist>
 <para>These options address the bounding box for Encapsulated PostScript
 graphic files, which have a size specified with a line
@@ -10379,7 +13929,7 @@
 20 40 80</literal> then its natural size is 30/72 inch wide by
 60/72 inch tall.
 </para>
-<variablelist><varlistentry><term><literal>bb</literal>
+<variablelist><anchor id="includegraphics-bb"/><varlistentry><term><literal>bb</literal>
 </term><listitem><para>Specify the bounding box of the displayed region.  The argument is four
 dimensions separated by spaces, as with <literal>\includegraphics[.., bb=
 0in 0in 1in 0.618in]{...}</literal>.  Usually <literal>\includegraphics</literal> reads the
@@ -10387,24 +13937,28 @@
 only useful if the bounding box is missing from that file or if you want
 to change it.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>bbllx, bblly, bburx, bbury</literal>
+<anchor id="includegraphics-bbllx"/><anchor id="includegraphics-bblly"/><anchor id="includegraphics-bburx"/><anchor id="includegraphics-bbury"/></listitem></varlistentry><varlistentry><term><literal>bbllx, bblly, bburx, bbury</literal>
 </term><listitem><para>Set the bounding box.  These four are obsolete, but are retained for
 compatibility with old packages.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>natwidth, natheight</literal>
+<anchor id="includegraphics-natwidth"/><anchor id="includegraphics-natheight"/></listitem></varlistentry><varlistentry><term><literal>natwidth, natheight</literal>
 </term><listitem><para>An alternative for <literal>bb</literal>.  Setting
-<literal>\includegraphics[...,natwidth=1in,natheight=0.618in,...]{...}</literal>
-is the same as setting <literal>bb=0 0 1in 0.618in</literal>.
+</para>
+<screen>\includegraphics[...,natwidth=1in,natheight=0.618in,...]{...}
+</screen>
+<para>is the same as setting <literal>bb=0 0 1in 0.618in</literal>.
 </para> 
-</listitem></varlistentry><varlistentry><term><literal>hiresbb</literal>
+<anchor id="includegraphics-hiresbb"/></listitem></varlistentry><varlistentry><term><literal>hiresbb</literal>
 </term><listitem><para>If set to <literal>true</literal>, or just specified as with
-<literal>\includegraphics[...,hiresbb,...]{...}</literal>, then &latex; will look
-for <literal>%%HiResBoundingBox</literal> lines instead of <literal>%%BoundingBox</literal>
-lines.  (The <literal>BoundingBox</literal> lines use only natural numbers while the
-<literal>HiResBoundingBox</literal> lines use decimals; both use units equivalent to
-&tex;’s big points, 1/72 inch.) To override a prior setting of
-<literal>true</literal>, you can set it to <literal>false</literal>.
 </para>
+<screen>\includegraphics[...,hiresbb,...]{...}
+</screen>
+<para>then &latex; will look for <literal>%%HiResBoundingBox</literal> lines instead of
+<literal>%%BoundingBox</literal> lines.  (The <literal>BoundingBox</literal> lines use only
+natural numbers while the <literal>HiResBoundingBox</literal> lines use decimals;
+both use units equivalent to &tex;’s big points, 1/72 inch.) To
+override a prior setting of <literal>true</literal>, you can set it to <literal>false</literal>.
+</para>
 </listitem></varlistentry></variablelist>
 <para>These following options allow a user to override &latex;’s method of
 choosing the graphic type based on the filename extension.  An example
@@ -10412,21 +13966,22 @@
 will read the file <filename>lion.xxx</filename> as though it were
 <filename>lion.png</filename>. For more on these, see <link linkend="_005cDeclareGraphicsRule">\DeclareGraphicsRule</link>.
 </para>
-<variablelist><varlistentry><term><literal>type</literal>
+<variablelist><anchor id="includegraphics-type"/><varlistentry><term><literal>type</literal>
 </term><listitem><para>Specify the graphics type.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>ext</literal>
+<anchor id="includegraphics-ext"/></listitem></varlistentry><varlistentry><term><literal>ext</literal>
 </term><listitem><para>Specify the graphics extension.
 Only use this in conjunction with the option <literal>type</literal>.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>read</literal>
+<anchor id="includegraphics-read"/></listitem></varlistentry><varlistentry><term><literal>read</literal>
 </term><listitem><para>Specify the file extension of the read file.
 Only use this in conjunction with the option <literal>type</literal>.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>command</literal>
-</term><listitem><para>Specify a command to be applied to this file.
-Only use this in conjunction with the option <literal>type</literal>.
-<!-- write18 and restricted execution. -->
+<anchor id="includegraphics-command"/></listitem></varlistentry><varlistentry><term><literal>command</literal>
+</term><listitem><para>Specify a command to be applied to this file.  Only use this in
+conjunction with the option <literal>type</literal>.  See <link linkend="Command-line-options">Command line options</link>
+for a discussion of enabling the <literal>\write18</literal> functionality to run
+external commands.
 </para>
 </listitem></varlistentry></variablelist>
 
@@ -10448,7 +14003,8 @@
 <screen>\rotatebox{<replaceable>angle</replaceable>}{<replaceable>material</replaceable>}
 \rotatebox[<replaceable>key-value list</replaceable>]{<replaceable>angle</replaceable>}{<replaceable>material</replaceable>}
 </screen>
-<para>Put <replaceable>material</replaceable> in a box and rotate it <replaceable>angle</replaceable> degrees counterclockwise. 
+<para>Put <replaceable>material</replaceable> in a box and rotate it <replaceable>angle</replaceable> degrees
+counterclockwise.
 </para>
 <para>This example rotates the table column heads forty five degrees.
 </para>
@@ -10480,16 +14036,19 @@
 </para>
 <variablelist><varlistentry><term><literal>origin</literal>
 </term><listitem><para>The point of the <replaceable>material</replaceable>’s box about which the rotation happens.
-Possible values are any string containing one or two of: <literal>l</literal> for
+Possible value is any string containing one or two of: <literal>l</literal> for
 left, <literal>r</literal> for right, <literal>b</literal> for bottom, <literal>c</literal> for center,
-<literal>t</literal> for top, and <literal>B</literal> for baseline.  Thus,
-<literal>\includegraphics[angle=180,origin=c]{moon}</literal> will turn the
-picture upside down from the center, while
-<literal>\includegraphics[angle=180,origin=lB]{LeBateau}</literal> will turn its
-picture upside down about its left baseline.  (The character <literal>c</literal>
-gives the horizontal center in <literal>bc</literal> or <literal>tc</literal> but gives the
-vertical center in <literal>lc</literal> or <literal>rc</literal>.)  The default is <literal>lB</literal>.
+<literal>t</literal> for top, and <literal>B</literal> for baseline.  Thus, the first line here
 </para>
+<screen>\includegraphics[angle=180,origin=c]{moon}
+\includegraphics[angle=180,origin=lB]{LeBateau}
+</screen>
+<para>will turn the picture upside down from the center while the second will
+turn its picture upside down about its left baseline.  (The character
+<literal>c</literal> gives the horizontal center in <literal>bc</literal> or <literal>tc</literal> but gives
+the vertical center in <literal>lc</literal> or <literal>rc</literal>.)  The default is
+<literal>lB</literal>.
+</para>
 </listitem></varlistentry><varlistentry><term><literal>x, y</literal>
 </term><listitem><para>Specify an arbitrary point of rotation with
 <literal>\rotatebox[x=<replaceable>&tex; dimension</replaceable>,y=<replaceable>&tex;
@@ -10532,10 +14091,12 @@
 <para>If you do not specify the optional <replaceable>vertical factor</replaceable> then it
 defaults to the same value as the <replaceable>horizontal factor</replaceable>.
 </para>
-<para>You can use this command to resize a graphic, as with
-<literal>\scalebox{0.5}{\includegraphics{lion}}</literal>.  If you use the
-<filename>graphicx</filename> package then you can accomplish the same thing with
-optional arguments to <literal>\includegraphics</literal>
+<para>You can use this command to resize a graphic, as here.
+</para>
+<screen>\scalebox{0.5}{\includegraphics{lion}}
+</screen>
+<para>If you use the <filename>graphicx</filename> package then you can accomplish the same
+thing with optional arguments to <literal>\includegraphics</literal>
 (see <link linkend="_005cincludegraphics">\includegraphics</link>).
 </para>
 <para>The <literal>\reflectbox</literal> command abbreviates
@@ -10604,8 +14165,8 @@
 <indexterm role="cp"><primary>characters, reserved</primary></indexterm>
 <indexterm role="cp"><primary>special characters</primary></indexterm>
 <indexterm role="cp"><primary>characters, special</primary></indexterm>
-<para>&latex; sets aside the following characters for special purposes (for
-example, the percent sign <literal>%</literal> is for comments) so they are
+<para>&latex; sets aside the following characters for special purposes. For
+example, the percent sign <literal>%</literal> is for comments.  They are
 called <firstterm>reserved characters</firstterm> or <firstterm>special characters</firstterm>.
 </para>
 <screen># $ % & { } _ ~ ^ \ 
@@ -10620,7 +14181,7 @@
 <para>If you want a reserved character to be printed as itself, in the text
 body font, for all but the final three characters in that list simply
 put a backslash <literal>\</literal> in front of the character.  Thus,
-<literal>\$1.23</literal> will produce <literal>$1.23</literal> in your output.
+typing <literal>\$1.23</literal> will produce <literal>$1.23</literal> in your output.
 </para>
 <indexterm role="fn"><primary>\~</primary></indexterm>
 <indexterm role="fn"><primary>\^</primary></indexterm>
@@ -10628,28 +14189,26 @@
 <para>As to the last three characters, to get a tilde in the text body font
 use <literal>\~{}</literal> (omitting the curly braces would result in the next
 character receiving a tilde accent).  Similarly, to get a get a text
-body font circumflex use <literal>\^{}</literal>.  A text body font backslash
-results from <literal>\textbackslash{}</literal>.
+body font circumflex use <literal>\^{}</literal>.  To get a backslash in the font
+of the text body, enter <literal>\textbackslash{}</literal>.
 </para>
 <para>To produce the reserved characters in a typewriter font use
-<literal>\verb!!</literal>, as below.
+<literal>\verb!!</literal> as below (the double backslash <literal>\\</literal> is only
+there to split the lines).
 </para>
 <screen>\begin{center}
   \# \$ \% \& \{ \} \_ \~{} \^{} \textbackslash \\
   \verb!# $ % & { } _ ~ ^ \!
 \end{center}
 </screen>
-<para>In that example the double backslash <literal>\\</literal> is only there to
-split the lines.
-</para>
 
 </sect1>
 <sect1 label="23.2" id="Upper-and-lower-case">
 <title>Upper and lower case</title>
 
-<indexterm role="cp"><primary>Upper case</primary></indexterm>
-<indexterm role="cp"><primary>Lower case</primary></indexterm>
-<indexterm role="cp"><primary>characters, case</primary></indexterm>
+<indexterm role="cp"><primary>uppercase</primary></indexterm>
+<indexterm role="cp"><primary>lowercase</primary></indexterm>
+<indexterm role="cp"><primary>characters, case of</primary></indexterm>
 
 <para>Synopsis:
 </para>
@@ -10729,22 +14288,23 @@
 <indexterm role="cp"><primary>symbols, text</primary></indexterm>
 
 <indexterm role="fn"><primary>textcomp package</primary></indexterm>
-<para>&latex; provides commands to generate a number of non-letter symbols
-in running text.  Some of these, especially the more obscure ones, are
-not available in OT1; you may need to load the <literal>textcomp</literal> package.
+<para>&latex; provides commands to generate a number of non-letter symbols in
+running text.  Some of these, especially the more obscure ones, are not
+available in OT1. Unless you are using Xe&latex; or Lua&latex; then
+you may need to load the <literal>textcomp</literal> package.
 </para>
 <variablelist><varlistentry><term><indexterm role="fn"><primary>\copyright</primary></indexterm><literal>\copyright</literal>
 </term><term><indexterm role="fn"><primary>\textcopyright</primary></indexterm><literal>\textcopyright</literal>
 </term><listitem><indexterm role="cp"><primary>copyright symbol</primary></indexterm>
-<para>The copyright symbol, ©.
+<para>© The copyright symbol.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\dag</primary></indexterm><literal>\dag</literal>
 </term><listitem><indexterm role="cp"><primary>dagger, in text</primary></indexterm>
-<para>The dagger symbol (in text).
+<para>&#x2020; The dagger symbol (in text).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\ddag</primary></indexterm><literal>\ddag</literal>
 </term><listitem><indexterm role="cp"><primary>double dagger, in text</primary></indexterm>
-<para>The double dagger symbol (in text).
+<para>&#x2021; The double dagger symbol (in text).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\LaTeX</primary></indexterm><literal>\LaTeX</literal>
 </term><listitem><indexterm role="cp"><primary>&latex; logo</primary></indexterm>
@@ -10768,50 +14328,50 @@
 <indexterm role="cp"><primary>single angle quotation marks</primary></indexterm>
 <indexterm role="cp"><primary>French quotation marks</primary></indexterm>
 <indexterm role="cp"><primary>quotation marks, French</primary></indexterm>
-<para>Double and single angle quotation marks, commonly used in French:
-«, », ‹, ›.
+<para>«, », ‹, ›
+Double and single angle quotation marks, commonly used in French.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\ldots</primary></indexterm><literal>\ldots</literal>
 </term><term><indexterm role="fn"><primary>\dots</primary></indexterm><literal>\dots</literal>
 </term><term><indexterm role="fn"><primary>\textellipsis</primary></indexterm><literal>\textellipsis</literal>
 </term><listitem><indexterm role="cp"><primary>ellipsis</primary></indexterm>
-<para>An ellipsis (three dots at the baseline): ‘…’.  <literal>\ldots</literal>
+<para>…  An ellipsis (three dots at the baseline):  <literal>\ldots</literal>
 and <literal>\dots</literal> also work in math mode.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\lq</primary></indexterm><literal>\lq</literal>
 </term><listitem><indexterm role="cp"><primary>left quote</primary></indexterm>
 <indexterm role="cp"><primary>opening quote</primary></indexterm>
-<para>Left (opening) quote: ‘.
+<para>‘ Left (opening) quote.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\P</primary></indexterm><literal>\P</literal>
 </term><term><indexterm role="fn"><primary>\textparagraph</primary></indexterm><literal>\textparagraph</literal>
 </term><listitem><indexterm role="cp"><primary>paragraph symbol</primary></indexterm>
 <indexterm role="cp"><primary>pilcrow</primary></indexterm>
-<para>Paragraph sign (pilcrow): &#x00B6;.
+<para>&#x00B6; Paragraph sign (pilcrow).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\pounds</primary></indexterm><literal>\pounds</literal>
 </term><term><indexterm role="fn"><primary>\textsterling</primary></indexterm><literal>\textsterling</literal>
 </term><listitem><indexterm role="cp"><primary>pounds symbol</primary></indexterm>
 <indexterm role="cp"><primary>sterling symbol</primary></indexterm>
-<para>English pounds sterling: £.
+<para>£ English pounds sterling.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\quotedblbase („)</primary></indexterm><literal>\quotedblbase („)</literal>
 </term><term><indexterm role="fn"><primary>\quotesinglbase (‚)</primary></indexterm><literal>\quotesinglbase (‚)</literal>
 </term><listitem><indexterm role="cp"><primary>double low-9 quotation mark</primary></indexterm>
 <indexterm role="cp"><primary>single low-9 quotation mark</primary></indexterm>
 <indexterm role="cp"><primary>low-9 quotation marks, single and double</primary></indexterm>
-<para>Double and single quotation marks on the baseline:
-„ and ‚.
+<para>„ and ‚
+Double and single quotation marks on the baseline.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\rq</primary></indexterm><literal>\rq</literal>
 </term><listitem><indexterm role="cp"><primary>right quote</primary></indexterm>
 <indexterm role="cp"><primary>closing quote</primary></indexterm>
-<para>Right (closing) quote: ’.
+<para>’ Right (closing) quote.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\S</primary></indexterm><literal>\S</literal>
-</term><listitem><para>\itemx \textsection
-<indexterm role="cp"><primary>section symbol</primary></indexterm>
-Section sign: &#x00A7;.
+</term><term><indexterm role="fn"><primary>\textsection</primary></indexterm><literal>\textsection</literal>
+</term><listitem><indexterm role="cp"><primary>section symbol</primary></indexterm>
+<para>&#x00A7; Section sign.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\TeX</primary></indexterm><literal>\TeX</literal>
 </term><listitem><indexterm role="cp"><primary>&tex; logo</primary></indexterm>
@@ -10821,55 +14381,55 @@
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textasciicircum</primary></indexterm><literal>\textasciicircum</literal>
 </term><listitem><indexterm role="cp"><primary>circumflex, ASCII, in text</primary></indexterm>
 <indexterm role="cp"><primary>ASCII circumflex, in text</primary></indexterm>
-<para>ASCII circumflex: ^.
+<para>^ ASCII circumflex.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textasciitilde</primary></indexterm><literal>\textasciitilde</literal>
 </term><listitem><indexterm role="cp"><primary>tilde, ASCII, in text</primary></indexterm>
 <indexterm role="cp"><primary>ASCII tilde, in text</primary></indexterm>
-<para>ASCII tilde: ~.
+<para>~ ASCII tilde.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textasteriskcentered</primary></indexterm><literal>\textasteriskcentered</literal>
 </term><listitem><indexterm role="cp"><primary>asterisk, centered, in text</primary></indexterm>
 <indexterm role="cp"><primary>centered asterisk, in text</primary></indexterm>
-<para>Centered asterisk: *.
+<para>* Centered asterisk.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textbackslash</primary></indexterm><literal>\textbackslash</literal>
 </term><listitem><indexterm role="cp"><primary>backslash, in text</primary></indexterm>
-<para>Backslash: \.
+<para>\ Backslash.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textbar</primary></indexterm><literal>\textbar</literal>
 </term><listitem><indexterm role="cp"><primary>vertical bar, in text</primary></indexterm>
 <indexterm role="cp"><primary>bar, vertical, in text</primary></indexterm>
-<para>Vertical bar: |.
+<para>| Vertical bar.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textbardbl</primary></indexterm><literal>\textbardbl</literal>
 </term><listitem><indexterm role="cp"><primary>vertical bar, double, in text</primary></indexterm>
 <indexterm role="cp"><primary>bar, double vertical, in text</primary></indexterm>
 <indexterm role="cp"><primary>double vertical bar, in text</primary></indexterm>
-<para>Double vertical bar.
+<para>&#x23F8; Double vertical bar.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textbigcircle</primary></indexterm><literal>\textbigcircle</literal>
 </term><listitem><indexterm role="cp"><primary>big circle symbols, in text</primary></indexterm>
 <indexterm role="cp"><primary>circle symbol, big, in text</primary></indexterm>
-<para>Big circle symbol.
+<para>&#x25EF; Big circle symbol.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textbraceleft</primary></indexterm><literal>\textbraceleft</literal>
 </term><listitem><indexterm role="cp"><primary>left brace, in text</primary></indexterm>
 <indexterm role="cp"><primary>brace, left, in text</primary></indexterm>
-<para>Left brace: {.
+<para>{ Left brace.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textbraceright</primary></indexterm><literal>\textbraceright</literal>
 </term><listitem><indexterm role="cp"><primary>right brace, in text</primary></indexterm>
 <indexterm role="cp"><primary>brace, right, in text</primary></indexterm>
-<para>Right brace: }.
+<para>} Right brace.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textbullet</primary></indexterm><literal>\textbullet</literal>
 </term><listitem><indexterm role="cp"><primary>bullet, in text</primary></indexterm>
-<para>Bullet: •.
+<para>• Bullet.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textcircled{<replaceable>letter</replaceable>}</primary></indexterm><literal>\textcircled{<replaceable>letter</replaceable>}</literal>
 </term><listitem><indexterm role="cp"><primary>circled letter, in text</primary></indexterm>
-<para><replaceable>letter</replaceable> in a circle, as in ®.
+<para>&#x24B6; Circle around <replaceable>letter</replaceable>.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textcompwordmark</primary></indexterm><literal>\textcompwordmark</literal>
 </term><term><indexterm role="fn"><primary>\textcapitalcompwordmark</primary></indexterm><literal>\textcapitalcompwordmark</literal>
@@ -10877,53 +14437,62 @@
 </term><listitem><indexterm role="cp"><primary>composite word mark, in text</primary></indexterm>
 <indexterm role="cp"><primary>cap height</primary></indexterm>
 <indexterm role="cp"><primary>ascender height</primary></indexterm>
-<para>Composite word mark (invisible).  The <literal>\textcapital...</literal> form
-has the cap height of the font, while the <literal>\textascender...</literal> form
-has the ascender height.
+<para>Used to separate letters that would normally ligature. For example,
+<literal>f\textcompwordmark i</literal> produces ‘<literal>fi</literal>’ without a ligature. This
+is most useful in non-English languages.  The
+<literal>\textcapitalcompwordmark</literal> form has the cap height of the font
+while the <literal>\textascendercompwordmark</literal> form has the ascender height.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textdagger</primary></indexterm><literal>\textdagger</literal>
 </term><listitem><indexterm role="cp"><primary>dagger, in text</primary></indexterm>
-<para>Dagger: <inlineequation><mathphrase>\dag</mathphrase></inlineequation>.
+<para>&#x2020; Dagger.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textdaggerdbl</primary></indexterm><literal>\textdaggerdbl</literal>
 </term><listitem><indexterm role="cp"><primary>dagger, double, in text</primary></indexterm>
 <indexterm role="cp"><primary>double dagger, in text</primary></indexterm>
-<para>Double dagger: <inlineequation><mathphrase>\ddag</mathphrase></inlineequation>.
+<para>&#x2021; Double dagger.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textdollar (or <literal>\$</literal>)</primary></indexterm><literal>\textdollar (or <literal>\$</literal>)</literal>
 </term><listitem><indexterm role="cp"><primary>dollar sign</primary></indexterm>
 <indexterm role="cp"><primary>currency, dollar</primary></indexterm>
-<para>Dollar sign: $.
+<para>$ Dollar sign.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textemdash (or <literal>---</literal>)</primary></indexterm><literal>\textemdash (or <literal>---</literal>)</literal>
 </term><listitem><indexterm role="cp"><primary>em-dash</primary></indexterm>
-<para>Em-dash: — (for punctuation).
+<para>— Em-dash (used for punctuation, as in
+<literal>The playoffs --- if you are fortunate enough to make the playoffs ---
+is more like a sprint.</literal>).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textendash (or <literal>--</literal>)</primary></indexterm><literal>\textendash (or <literal>--</literal>)</literal>
 </term><listitem><indexterm role="cp"><primary>e-dash</primary></indexterm>
-<para>En-dash: – (for ranges).
+<para>– En-dash (used for ranges, as in <literal>See pages 12--14</literal>).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\texteuro</primary></indexterm><literal>\texteuro</literal>
 </term><listitem><indexterm role="cp"><primary>euro symbol</primary></indexterm>
 <indexterm role="cp"><primary>currency, euro</primary></indexterm>
-<para>The Euro symbol: €.
+<indexterm role="cp"><primary>package, <literal>eurosym</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>eurosym</literal> package</primary></indexterm>
+
+<para>The Euro symbol: €. For an alternative glyph design, try the
+<filename>eurosym</filename> package; also, most fonts nowadays come with their own
+Euro symbol (Unicode U+20AC).
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textexclamdown (or <literal>!`</literal>)</primary></indexterm><literal>\textexclamdown (or <literal>!`</literal>)</literal>
 </term><listitem><indexterm role="cp"><primary>exclamation point, upside-down</primary></indexterm>
-<para>Upside down exclamation point: ¡.
+<para>¡ Upside down exclamation point.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textgreater</primary></indexterm><literal>\textgreater</literal>
 </term><listitem><indexterm role="cp"><primary>greater than symbol, in text</primary></indexterm>
-<para>Greater than: >.
+<para>> Greater than symbol.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textless</primary></indexterm><literal>\textless</literal>
 </term><listitem><indexterm role="cp"><primary>less than symbol, in text</primary></indexterm>
-<para>Less than: <.
+<para>< Less than symbol.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textleftarrow</primary></indexterm><literal>\textleftarrow</literal>
 </term><listitem><indexterm role="cp"><primary>arrow, left, in text</primary></indexterm>
 <indexterm role="cp"><primary>left arrow, in text</primary></indexterm>
-<para>Left arrow.
+<para>&#x2190; Left arrow.   
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textordfeminine</primary></indexterm><literal>\textordfeminine</literal>
 </term><term><indexterm role="fn"><primary>\textordmasculine</primary></indexterm><literal>\textordmasculine</literal>
@@ -10931,42 +14500,42 @@
 <indexterm role="cp"><primary>masculine ordinal symbol</primary></indexterm>
 <indexterm role="cp"><primary>ordinals, feminine and masculine</primary></indexterm>
 <indexterm role="cp"><primary>Spanish ordinals, feminine and masculine</primary></indexterm>
-<para>Feminine and masculine ordinal symbols: ª, º.
+<para>ª, º Feminine and masculine ordinal symbols.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textperiodcentered</primary></indexterm><literal>\textperiodcentered</literal>
 </term><listitem><indexterm role="cp"><primary>period, centered, in text</primary></indexterm>
 <indexterm role="cp"><primary>centered period, in text</primary></indexterm>
-<para>Centered period: &#x00B7;.
+<para>&#x00B7; Centered period.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textquestiondown (or <literal>?`</literal>)</primary></indexterm><literal>\textquestiondown (or <literal>?`</literal>)</literal>
 </term><listitem><indexterm role="cp"><primary>question mark, upside-down</primary></indexterm>
-<para>Upside down question mark: ¿.
+<para>¿ Upside down question mark.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textquotedblleft (or <literal>``</literal>)</primary></indexterm><literal>\textquotedblleft (or <literal>``</literal>)</literal>
 </term><listitem><indexterm role="cp"><primary>left quote, double</primary></indexterm>
 <indexterm role="cp"><primary>double left quote</primary></indexterm>
-<para>Double left quote: “.
+<para>“ Double left quote.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textquotedblright (or <literal>''</literal>)</primary></indexterm><literal>\textquotedblright (or <literal>''</literal>)</literal>
 </term><listitem><indexterm role="cp"><primary>right quote, double</primary></indexterm>
 <indexterm role="cp"><primary>double right quote</primary></indexterm>
-<para>Double right quote: ”.
+<para>” Double right quote.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textquoteleft (or <literal>`</literal>)</primary></indexterm><literal>\textquoteleft (or <literal>`</literal>)</literal>
 </term><listitem><indexterm role="cp"><primary>left quote, single</primary></indexterm>
 <indexterm role="cp"><primary>single left quote</primary></indexterm>
-<para>Single left quote: ‘.
+<para>‘ Single left quote.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textquoteright (or <literal>'</literal>)</primary></indexterm><literal>\textquoteright (or <literal>'</literal>)</literal>
 </term><listitem><indexterm role="cp"><primary>right quote, single</primary></indexterm>
 <indexterm role="cp"><primary>single right quote</primary></indexterm>
-<para>Single right quote: ’.
+<para>’ Single right quote.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textquotesingle</primary></indexterm><literal>\textquotesingle</literal>
 </term><listitem><indexterm role="cp"><primary>quote, single straight</primary></indexterm>
 <indexterm role="cp"><primary>straight single quote</primary></indexterm>
 <indexterm role="cp"><primary>single quote, straight</primary></indexterm>
-<para>Straight single quote.  (From TS1 encoding.)
+<para>&#x0027; Straight single quote.  (From TS1 encoding.)  
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textquotestraightbase</primary></indexterm><literal>\textquotestraightbase</literal>
 </term><term><indexterm role="fn"><primary>\textquotestraightdblbase</primary></indexterm><literal>\textquotestraightdblbase</literal>
@@ -10974,38 +14543,40 @@
 <indexterm role="cp"><primary>straight quote, base</primary></indexterm>
 <indexterm role="cp"><primary>double quote, straight base</primary></indexterm>
 <indexterm role="cp"><primary>straight double quote, base</primary></indexterm>
+<!-- Unicode doesn't have these https://en.wikipedia.org/wiki/Quotation_mark -->
 <para>Single and double straight quotes on the baseline.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textregistered</primary></indexterm><literal>\textregistered</literal>
 </term><listitem><indexterm role="cp"><primary>registered symbol</primary></indexterm>
-<para>Registered symbol: ®.
+<para>® Registered symbol.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textrightarrow</primary></indexterm><literal>\textrightarrow</literal>
 </term><listitem><indexterm role="cp"><primary>arrow, right, in text</primary></indexterm>
 <indexterm role="cp"><primary>right arrow, in text</primary></indexterm>
-<para>Right arrow.
+<para>&#x2192; Right arrow.  
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textthreequartersemdash</primary></indexterm><literal>\textthreequartersemdash</literal>
 </term><listitem><indexterm role="cp"><primary>three-quarters em-dash</primary></indexterm>
 <indexterm role="cp"><primary>em-dash, three-quarters</primary></indexterm>
-<para>“Three-quarters” em-dash, between en-dash and em-dash.
+<para>&#xFE58; “Three-quarters” em-dash, between en-dash and em-dash.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\texttrademark</primary></indexterm><literal>\texttrademark</literal>
 </term><listitem><indexterm role="cp"><primary>trademark symbol</primary></indexterm>
-<para>Trademark symbol: &#x2122;.
+<para>&#x2122; Trademark symbol.
 </para>
+<!-- ?? Diff from \textthreequartersemdash?  In Unicode? -->
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\texttwelveudash</primary></indexterm><literal>\texttwelveudash</literal>
 </term><listitem><indexterm role="cp"><primary>two-thirds em-dash</primary></indexterm>
 <indexterm role="cp"><primary>em-dash, two-thirds</primary></indexterm>
-<para>“Two-thirds” em-dash, between en-dash and em-dash.
+<para>&#xFE58; “Two-thirds” em-dash, between en-dash and em-dash.   
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textunderscore</primary></indexterm><literal>\textunderscore</literal>
 </term><listitem><indexterm role="cp"><primary>underscore, in text</primary></indexterm>
-<para>Underscore: _.
+<para>_ Underscore.
 </para>
 </listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>\textvisiblespace</primary></indexterm><literal>\textvisiblespace</literal>
 </term><listitem><indexterm role="cp"><primary>visible space symbol, in text</primary></indexterm>
-<para>Visible space symbol.
+<para>&#x2423; Visible space symbol.  
 </para>
 </listitem></varlistentry></variablelist>
 
@@ -11020,37 +14591,52 @@
 <indexterm role="cp"><primary>package, <literal>babel</literal></primary></indexterm>
 <indexterm role="cp"><primary><literal>babel</literal> package</primary></indexterm>
 
+<indexterm role="cp"><primary>package, <literal>polyglossia</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>polyglossia</literal> package</primary></indexterm>
+
 <indexterm role="cp"><primary>multilingual support</primary></indexterm>
-<para>&latex; has wide support for many of the world’s scripts and
-languages, through the <literal>babel</literal> package and related support.  This
-section does not attempt to cover all that support.  It merely lists
-the core &latex; commands for creating accented characters.
+<para>&latex; has wide support for many of the world’s scripts and languages,
+through the <literal>babel</literal> package and related support if you are using
+pdf&latex;, or <filename>polyglossia</filename> if you are using Xe&latex; or
+Lua&latex;.  This section does not cover that support. It only lists
+the core &latex; commands for creating accented characters.  The
+<literal>\capital...</literal> commands shown here produce alternative forms for use
+with capital letters.  These are not available with OT1.
 </para>
-<para>The <literal>\capital...</literal> commands produce alternative forms for use with
-capital letters.  These are not available with OT1.
+<para>Below, to make them easier to find, the accents are all illustrated with
+lowercase ‘<literal>o</literal>’.
 </para>
+<indexterm role="fn"><primary>\i (dotless i)</primary></indexterm>
+<indexterm role="cp"><primary>dotless i</primary></indexterm>
+<para>Note that <literal>\i</literal> produces a dotless i,
+<!-- @dotless{i}, -->
+<indexterm role="fn"><primary>\j (dotless j)</primary></indexterm>
+<indexterm role="cp"><primary>dotless j</primary></indexterm>
+and <literal>\j</literal> produces a dotless j.
+<!-- @dotless{j}. -->
+These are often used in place of their dotted counterparts when they are
+accented.
+</para>
 <variablelist><varlistentry><term><literal>\"</literal>
 </term><term><literal>\capitaldieresis</literal>
 </term><listitem><indexterm role="fn"><primary>\" (umlaut accent)</primary></indexterm>
 <indexterm role="fn"><primary>\capitaldieresis</primary></indexterm>
 <indexterm role="cp"><primary>umlaut accent</primary></indexterm>
 <indexterm role="cp"><primary>dieresis accent</primary></indexterm>
-<para>Produces an umlaut (dieresis), as in ö.
+<para>ö Umlaut (dieresis).
 </para>
 </listitem></varlistentry><varlistentry><term><literal>\'</literal>
 </term><term><literal>\capitalacute</literal>
 </term><listitem><indexterm role="fn"><primary>\' (acute accent)</primary></indexterm>
 <indexterm role="fn"><primary>\capitalacute</primary></indexterm>
 <indexterm role="cp"><primary>acute accent</primary></indexterm>
-<para>Produces an acute accent, as in ó.  In the <literal>tabbing</literal>
-environment, pushes current column to the right of the previous column
-(see <link linkend="tabbing">tabbing</link>).
+<para>ó Acute accent.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>\.</literal>
 </term><listitem><indexterm role="fn"><primary>\. (dot-over accent)</primary></indexterm>
 <indexterm role="cp"><primary>dot accent</primary></indexterm>
 <indexterm role="cp"><primary>dot-over accent</primary></indexterm>
-<para>Produces a dot accent over the following, as in ȯ.
+<para>ȯ  Dot accent.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>\=</literal>
 </term><term><literal>\capitalmacron</literal>
@@ -11059,7 +14645,7 @@
 <indexterm role="cp"><primary>macron accent</primary></indexterm>
 <indexterm role="cp"><primary>overbar accent</primary></indexterm>
 <indexterm role="cp"><primary>bar-over accent</primary></indexterm>
-<para>Produces a macron (overbar) accent over the following, as in ō.
+<para>ō Macron (overbar) accent.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>\^</literal>
 </term><term><literal>\capitalcircumflex</literal>
@@ -11067,75 +14653,69 @@
 <indexterm role="fn"><primary>\capitalcircumflex</primary></indexterm>
 <indexterm role="cp"><primary>circumflex accent</primary></indexterm>
 <indexterm role="cp"><primary>hat accent</primary></indexterm>
-<para>Produces a circumflex (hat) accent over the following, as in ô.
+<para>ô Circumflex (hat) accent.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>\`</literal>
 </term><term><literal>\capitalgrave</literal>
 </term><listitem><indexterm role="fn"><primary>\` (grave accent)</primary></indexterm>
 <indexterm role="fn"><primary>\capitalgrave</primary></indexterm>
 <indexterm role="cp"><primary>grave accent</primary></indexterm>
-<para>Produces a grave accent over the following, as in ò.  In the
-<literal>tabbing</literal> environment, move following text to the right margin
-(see <link linkend="tabbing">tabbing</link>).
+<para>ò Grave accent.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>\~</literal>
 </term><term><literal>\capitaltilde</literal>
 </term><listitem><indexterm role="fn"><primary>\~ (tilde accent)</primary></indexterm>
 <indexterm role="fn"><primary>\capitaltilde</primary></indexterm>
 <indexterm role="cp"><primary>tilde accent</primary></indexterm>
-<para>Produces a tilde accent over the following, as in ñ.
+<para>ñ Tilde accent.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>\b</literal>
 </term><listitem><indexterm role="fn"><primary>\b (bar-under accent)</primary></indexterm>
 <indexterm role="cp"><primary>bar-under accent</primary></indexterm>
-<para>Produces a bar accent under the following, as in o_. See
-also <literal>\underbar</literal> hereinafter.
+<para>o_ Bar accent underneath.
 </para>
+<indexterm role="fn"><primary>\underbar</primary></indexterm>
+<indexterm role="cp"><primary>underbar</primary></indexterm>
+<para>Related to this, <literal>\underbar{<replaceable>text</replaceable>}</literal> produces a bar under
+<replaceable>text</replaceable>.  The argument is always processed in LR mode
+(see <link linkend="Modes">Modes</link>).  The bar is always a fixed position under the baseline,
+thus crossing through descenders.  See also <literal>\underline</literal> in
+<link linkend="Math-miscellany">Math miscellany</link>.
+</para>
 </listitem></varlistentry><varlistentry><term><literal>\c</literal>
 </term><term><literal>\capitalcedilla</literal>
 </term><listitem><indexterm role="fn"><primary>\c (cedilla accent)</primary></indexterm>
 <indexterm role="fn"><primary>\capitalcedilla</primary></indexterm>
 <indexterm role="cp"><primary>cedilla accent</primary></indexterm>
-<para>Produces a cedilla accent under the following, as in ç.
+<para>ç Cedilla accent underneath.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>\d</literal>
 </term><term><literal>\capitaldotaccent</literal>
 </term><listitem><indexterm role="fn"><primary>\d (dot-under accent)</primary></indexterm>
 <indexterm role="fn"><primary>\capitaldotaccent</primary></indexterm>
 <indexterm role="cp"><primary>dot-under accent</primary></indexterm>
-<para>Produces a dot accent under the following, as in ọ.
+<para>ọ Dot accent underneath.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>\H</literal>
 </term><term><literal>\capitalhungarumlaut</literal>
 </term><listitem><indexterm role="fn"><primary>\H (Hungarian umlaut accent)</primary></indexterm>
 <indexterm role="fn"><primary>\capitalhungarumlaut</primary></indexterm>
 <indexterm role="cp"><primary>hungarian umlaut accent</primary></indexterm>
-<para>Produces a long Hungarian umlaut accent over the following, as in ő.
+<para>ő Long Hungarian umlaut accent.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>\i</literal>
-</term><listitem><indexterm role="fn"><primary>\i (dotless i)</primary></indexterm>
-<indexterm role="cp"><primary>dotless i</primary></indexterm>
-<para>Produces a dotless i, as in ‘i’.
-</para>
-</listitem></varlistentry><varlistentry><term><literal>\j</literal>
-</term><listitem><indexterm role="fn"><primary>\j (dotless j)</primary></indexterm>
-<indexterm role="cp"><primary>dotless j</primary></indexterm>
-<para>Produces a dotless j, as in ‘j’.
-</para>
 </listitem></varlistentry><varlistentry><term><literal>\k</literal>
 </term><term><literal>\capitalogonek</literal>
 </term><listitem><indexterm role="fn"><primary>\k (ogonek)</primary></indexterm>
 <indexterm role="fn"><primary>\capitalogonek</primary></indexterm>
 <indexterm role="cp"><primary>ogonek</primary></indexterm>
-<para>Produces a letter with ogonek, as in ‘ǫ’.  Not available in
-the OT1 encoding.
+<para>ǫ Ogonek.  Not available in the OT1 encoding.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>\r</literal>
 </term><term><literal>\capitalring</literal>
 </term><listitem><indexterm role="fn"><primary>\r (ring accent)</primary></indexterm>
 <indexterm role="fn"><primary>\capitalring</primary></indexterm>
 <indexterm role="cp"><primary>ring accent</primary></indexterm>
-<para>Produces a ring accent, as in ‘o*’.
+<para>o* Ring accent.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>\t</literal>
 </term><term><literal>\capitaltie</literal>
@@ -11146,25 +14726,16 @@
 <indexterm role="fn"><primary>\newtie</primary></indexterm>
 <indexterm role="fn"><primary>\capitalnewtie</primary></indexterm>
 <indexterm role="cp"><primary>tie-after accent</primary></indexterm>
-<para>Produces a tie-after accent, as in ‘oo[’.  The
-<literal>\newtie</literal> form is centered in its box.
+<para>oo[ Tie-after accent.  The <literal>\newtie</literal> form is centered in
+its box.
 </para>
 </listitem></varlistentry><varlistentry><term><literal>\u</literal>
 </term><term><literal>\capitalbreve</literal>
 </term><listitem><indexterm role="fn"><primary>\u (breve accent)</primary></indexterm>
 <indexterm role="fn"><primary>\capitalbreve</primary></indexterm>
 <indexterm role="cp"><primary>breve accent</primary></indexterm>
-<para>Produces a breve accent, as in ‘ŏ’.
+<para>ŏ Breve accent.
 </para>
-</listitem></varlistentry><varlistentry><term><literal>\underbar</literal>
-</term><listitem><indexterm role="fn"><primary>\underbar</primary></indexterm>
-<indexterm role="cp"><primary>underbar</primary></indexterm>
-<para>Not exactly an accent, this produces a bar under the argument text.
-The argument is always processed in horizontal mode.  The bar is
-always a fixed position under the baseline, thus crossing through
-descenders.  See also <literal>\underline</literal> in <link linkend="Math-miscellany">Math miscellany</link>.
-See also <literal>\b</literal> above.
-</para>
 </listitem></varlistentry><varlistentry><term><literal>\v</literal>
 </term><term><literal>\capitalcaron</literal>
 </term><listitem><indexterm role="fn"><primary>\v (breve accent)</primary></indexterm>
@@ -11172,7 +14743,7 @@
 <indexterm role="cp"><primary>hacek accent</primary></indexterm>
 <indexterm role="cp"><primary>check accent</primary></indexterm>
 <indexterm role="cp"><primary>caron accent</primary></indexterm>
-<para>Produces a háček (check, caron) accent, as in ‘ǒ’.
+<para>ǒ  Háček (check, caron) accent.
 </para>
 </listitem></varlistentry></variablelist>
 
@@ -11187,8 +14758,8 @@
 <indexterm role="cp"><primary>non-English characters</primary></indexterm>
 <indexterm role="cp"><primary>characters, non-English</primary></indexterm>
 
-<para>Here are the basic &latex; commands for inserting letters (beyond
-A–Z) extending the Latin alphabet, used primarily in languages other
+<para>Here are the basic &latex; commands for inserting letters beyond
+A–Z that extend the Latin alphabet, used primarily in languages other
 than English.
 </para>
 <variablelist><varlistentry><term><literal>\aa</literal>
@@ -11283,22 +14854,43 @@
 
 <indexterm role="fn"><primary>\rule</primary></indexterm>
 
-<para>Synopsis:
+<para>Synopsis, one of:
 </para>
-<screen>\rule[<replaceable>raise</replaceable>]{<replaceable>width</replaceable>}{<replaceable>thickness</replaceable>}
+<screen>\rule{<replaceable>width</replaceable>}{<replaceable>thickness</replaceable>}
+\rule[<replaceable>raise</replaceable>]{<replaceable>width</replaceable>}{<replaceable>thickness</replaceable>}
 </screen>
-<para>The <literal>\rule</literal> command produces <firstterm>rules</firstterm>, that is, lines or
-rectangles.  The arguments are:
+<para>Produce a <firstterm>rule</firstterm>, a filled-in rectangle.
 </para>
-<variablelist><varlistentry><term><replaceable>raise</replaceable>
-</term><listitem><para>How high to raise the rule (optional).
+<indexterm role="cp"><primary>Halmos symbol</primary></indexterm>
+<indexterm role="cp"><primary>tombstone</primary></indexterm>
+<para>This produces a rectangular blob, sometimes called a Halmos symbol,
+often used to mark the end of a proof.
 </para>
-</listitem></varlistentry><varlistentry><term><replaceable>width</replaceable>
-</term><listitem><para>The length of the rule (mandatory).
+<screen>\newcommand{\qedsymbol}{\rule{0.4em}{2ex}}
+</screen>
+<indexterm role="cp"><primary>package, <literal>amsthm</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>amsthm</literal> package</primary></indexterm>
+
+<para>The <filename>amsthm</filename> package includes this command, with a somewhat
+different-looking symbol.
 </para>
-</listitem></varlistentry><varlistentry><term><replaceable>thickness</replaceable>
-</term><listitem><para>The thickness of the rule (mandatory).
-</para></listitem></varlistentry></variablelist>
+<para>The mandatory arguments give the horizontal <replaceable>width</replaceable> and vertical
+<replaceable>thickness</replaceable> of the rectangle.  They are rigid lengths
+(see <link linkend="Lengths">Lengths</link>).  The optional argument <replaceable>raise</replaceable> is also a rigid
+length, and tells &latex; how much to raise the rule above the
+baseline, or lower it if the length is negative.
+</para>
+<para>This produces a line, a rectangle that is wide but not tall.
+</para>
+<screen>\noindent\rule{\textwidth}{0.4pt}
+</screen>
+<para>The line is the width of the page and 0.4 points tall.  This line
+thickness is common in &latex;.
+</para>
+<para>A rule that has zero width, or zero thickness, will not show up in the
+output, but can cause &latex; to change the output around it.
+See <link linkend="_005cstrut">\strut</link> for examples.
+</para>
 
 </sect1>
 <sect1 label="23.8" id="_005ctoday">
@@ -11306,17 +14898,26 @@
 
 <indexterm role="fn"><primary>\today</primary></indexterm>
 <indexterm role="cp"><primary>date, today’s</primary></indexterm>
+<indexterm role="cp"><primary>today’s date</primary></indexterm>
 
-<para>The <literal>\today</literal> command produces today’s date, in the format
-‘<literal><replaceable>month</replaceable> <replaceable>dd</replaceable>, <replaceable>yyyy</replaceable></literal>’; for example, ‘<literal>July 4, 1976</literal>’.
-It uses the predefined counters <literal>\day</literal>, <literal>\month</literal>, and
-<literal>\year</literal> (see <link linkend="_005cday-_005cmonth-_005cyear">\day \month \year</link>) to do this.  It is not
-updated as the program runs.
+<para>Synopsis:
 </para>
-<para>Multilingual packages like <filename>babel</filename> or classes like <filename>lettre</filename>,
-among others, will localize <literal>\today</literal>. For example, the following
-will output ‘<literal>4 juillet 1976</literal>’:
+<screen>\today
+</screen>
+<para>Produce today’s date in the format ‘<literal><replaceable>month</replaceable> <replaceable>dd</replaceable>,
+<replaceable>yyyy</replaceable></literal>’.  An example of a date in that format is ‘<literal>July 4,
+1976</literal>’.
 </para>
+<indexterm role="cp"><primary>package, <literal>babel</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>babel</literal> package</primary></indexterm>
+
+<indexterm role="cp"><primary>package, <literal>polyglossia</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>polyglossia</literal> package</primary></indexterm>
+
+<para>Multilingual packages such as <filename>babel</filename> or <filename>polyglossia</filename>, or
+classes such as <filename>lettre</filename>, will localize <literal>\today</literal>. For example,
+the following will output ‘<literal>4 juillet 1976</literal>’:
+</para>
 <screen>\year=1976 \month=7 \day=4
 \documentclass{minimal}
 \usepackage[french]{babel}
@@ -11324,12 +14925,18 @@
 \today
 \end{document}
 </screen>
+<para><literal>\today</literal> uses the counters <literal>\day</literal>, <literal>\month</literal>, and
+<literal>\year</literal> (see <link linkend="_005cday-_0026-_005cmonth-_0026-_005cyear">\day & \month & \year</link>).
+</para>
 <indexterm role="cp"><primary>package, <literal>datetime</literal></primary></indexterm>
 <indexterm role="cp"><primary><literal>datetime</literal> package</primary></indexterm>
 
-<para>The <literal>datetime</literal> package, among others, can produce a wide variety
-of other date formats.
+<para>A number of package on CTAN work with dates.  One is <filename>datetime</filename> package
+which can produce a wide variety of date formats, including ISO standards.
 </para>
+<para>The date is not updated as the &latex; process runs, so in principle the
+date could be incorrect by the time the program finishes.
+</para>
 
 </sect1>
 </chapter>
@@ -11339,61 +14946,215 @@
 <indexterm role="cp"><primary>splitting the input file</primary></indexterm>
 <indexterm role="cp"><primary>input file</primary></indexterm>
 
-<para>A large document requires a lot of input.  Rather than putting the whole
-input in a single large file, it’s more efficient to split it into
-several smaller ones.  Regardless of how many separate files you use,
-there is one that is the 
+<para>&latex; lets you split a large document into several smaller ones.
+This can simplify editing or allow multiple authors to work on the
+document.  It can also speed processing.
+</para>
+<para>Regardless of how many separate files you use, there is always one
 <indexterm role="cp"><primary>root file</primary></indexterm>
 <indexterm role="cp"><primary>file, root</primary></indexterm>
-<firstterm>root file</firstterm>; it is the one whose name you type
-when you run &latex;.
+<firstterm>root file</firstterm>, on which &latex; compilation starts.  This shows such
+a file with five included files.
 </para>
-<para>See <link linkend="filecontents">filecontents</link>, for an environment that allows bundling an
-external file to be created with the main document.
+<screen>\documentclass{book}
+\includeonly{  % comment out lines below to omit compiling
+  pref,
+  chap1,
+  chap2,
+  append,
+  bib
+  }
+\begin{document}
+\frontmatter
+\include{pref} 
+\mainmatter
+\include{chap1} 
+\include{chap2}
+\appendix
+\include{append}
+\backmatter
+\include{bib} 
+\end{document}
+</screen>
+<para>This will bring in material from <filename>pref.tex</filename>, <filename>chap1.tex</filename>,
+<filename>chap2.tex</filename>, <filename>append.tex</filename>, and <filename>bib.tex</filename>.  If you compile
+this file, and then comment out all of the lines inside
+<literal>\includeonly{...}</literal> except for <literal>chap1,</literal> and compile again,
+then &latex; will only process the material in the first chapter.
+Thus, your output will appear more quickly and be shorter to print.
+However, the advantage of the <literal>\includeonly</literal> command is that
+&latex; will retain the page numbers and all of the cross reference
+information from the other parts of the document so these will appear in
+your output correctly.
 </para>
+<para>See <link linkend="Larger-book-template">Larger book template</link> for another example of <literal>\includeonly</literal>.
+</para>
 
 
-<sect1 label="24.1" id="_005cinclude">
-<title><literal>\include</literal></title>
 
-<indexterm role="fn"><primary>\include</primary></indexterm>
+<sect1 label="24.1" id="_005cendinput">
+<title><literal>\endinput</literal></title>
 
+<indexterm role="fn"><primary>\endinput</primary></indexterm>
+
 <para>Synopsis:
 </para>
-<screen>\include{<replaceable>file</replaceable>}
+<screen>\endinput
 </screen>
-<para>If no <literal>\includeonly</literal> command is present, the <literal>\include</literal>
-command executes <literal>\clearpage</literal> to start a new page
-(see <link linkend="_005cclearpage">\clearpage</link>), then reads <replaceable>file</replaceable>, then does another
-<literal>\clearpage</literal>.
+<para>When you <literal>\include{filename}</literal>, inside <filename>filename.tex</filename> the
+material after <literal>\endinput</literal> will not be included.  This command is
+optional; if <filename>filename.tex</filename> has no <literal>\endinput</literal> then &latex;
+will read all of the file.
 </para>
-<para>Given an <literal>\includeonly</literal> command, the <literal>\include</literal> actions are
-only run if <replaceable>file</replaceable> is listed as an argument to
-<literal>\includeonly</literal>.  See <link linkend="_005cincludeonly">\includeonly</link>.
+<para>For example, suppose that a document’s root file has
+<literal>\input{chap1}</literal> and this is <filename>chap1.tex</filename>.
 </para>
-<indexterm role="cp"><primary>nested <literal>\include</literal>, not allowed</primary></indexterm>
-<para>The <literal>\include</literal> command may not appear in the preamble or in a file
-read by another <literal>\include</literal> command.
+<screen>\chapter{One}
+This material will appear in the document. 
+\endinput
+This will not appear.
+</screen>
+<para>This can be useful for putting documentation or comments at the end of a
+file, or for avoiding junk characters that can be added during mailing.
+It is also useful for debugging: one strategy to localize errors is to
+put <literal>\endinput</literal> halfway through the included file and see if the
+error disappears.  Now, knowing which half contains the error, moving
+<literal>\endinput</literal> to halfway through that area further narrows down the
+location. This process rapidly finds the offending line.
 </para>
+<para>After reading <literal>\endinput</literal>, &latex; continues to read to the end of
+the line, so something can follow this command and be read nonetheless.
+This allows you, for instance, to close an <literal>\if...</literal> with a
+<literal>\fi</literal>.
+</para>
 
 </sect1>
-<sect1 label="24.2" id="_005cincludeonly">
-<title><literal>\includeonly</literal></title>
+<sect1 label="24.2" id="_005cinclude-_0026-_005cincludeonly">
+<title><literal>\include</literal> & <literal>\includeonly</literal></title>
 
+<indexterm role="fn"><primary>\include</primary></indexterm>
 <indexterm role="fn"><primary>\includeonly</primary></indexterm>
 
 <para>Synopsis:
 </para>
-<screen>\includeonly{<replaceable>file1</replaceable>,<replaceable>file2</replaceable>,...}
+<screen>\includeonly{  % in document preamble
+  ...
+  <replaceable>filename</replaceable>,
+  ...
+  }
+  ...
+\include{<replaceable>filename</replaceable>}  % in document body 
 </screen>
-<para>The <literal>\includeonly</literal> command controls which files will be read by
-subsequent <literal>\include</literal> commands.  The list of filenames is
-comma-separated. Each element <replaceable>file1</replaceable>, <replaceable>file2</replaceable>, … must
-exactly match a filename specified in a <literal>\include</literal> command for the
-selection to be effective.
+<para>Bring material from the external file <filename><replaceable>filename</replaceable>.tex</filename> into a
+&latex; document.
 </para>
-<para>This command can only appear in the preamble.
+<para>The <literal>\include</literal> command does three things: it executes
+<literal>\clearpage</literal> (see <link linkend="_005cclearpage-_0026-_005ccleardoublepage">\clearpage & \cleardoublepage</link>), then it
+inputs the material from <filename><replaceable>filename</replaceable>.tex</filename> into the document,
+and then it does another <literal>\clearpage</literal>.  This command can only
+appear in the document body.  The <literal>\includeonly</literal> command controls
+which files will be read by &latex; under subsequent <literal>\include</literal>
+commands.  Its list of filenames is comma-separated, and it can only
+appear in the preamble.
 </para>
+<para>This example root document, <filename>constitution.tex</filename>, brings in
+three files, <filename>preamble.tex</filename>, <filename>articles.tex</filename>, and
+<filename>amendments.tex</filename>.
+</para>
+<screen>\documentclass{book}
+\includeonly{
+  preamble,
+  articles,
+  amendments
+  }
+\begin{document}
+\include{preamble}
+\include{articles}
+\include{amendments}
+\end{document}
+</screen>
+<para>The file <filename>preamble.tex</filename> contains no special code; you have just
+excerpted the chapter from <filename>consitution.tex</filename> and put it in a
+separate file just for editing convenience.
+</para>
+<screen>\chapter{Preamble}
+We the People of the United States,
+in Order to form a more perfect Union, ...
+</screen>
+<para>Running &latex; on <filename>constitution.tex</filename> makes the material from the
+three files appear in the document but also generates the auxiliary
+files <filename>preamble.aux</filename>, <filename>articles.aux</filename>, and
+<filename>amendments.tex</filename>. These contain information such as page numbers
+and cross-references (see <link linkend="Cross-references">Cross references</link>).  If you now comment out
+<literal>\includeonly</literal>’s lines with <literal>preamble</literal> and <literal>amendments</literal>
+and run &latex; again then the resulting document shows only the
+material from <filename>articles.tex</filename>, not the material from
+<filename>preamble.tex</filename> or <filename>amendments.tex</filename>.  Nonetheless, all of the
+auxiliary information from the omitted files is still there, including
+the starting page number of the chapter.
+</para>
+<para>If the document preamble does not have <literal>\includeonly</literal> then
+&latex; will include all the files you call for with <literal>\include</literal>
+commands.
+</para>
+<para>The <literal>\include</literal> command makes a new page.  To avoid that, see
+<link linkend="_005cinput">\input</link> (which, however, does not retain the auxiliary
+information).
+</para>
+<para>See <link linkend="Larger-book-template">Larger book template</link> for another example using <literal>\include</literal>
+and <literal>\includeonly</literal>.  That example also uses <literal>\input</literal> for some
+material that will not necessarily start on a new page.
+</para>
+<para>File names can involve paths.
+</para>
+<screen>\documentclass{book}
+\includeonly{
+  chapters/chap1,
+  }
+\begin{document}
+\include{chapters/chap1}
+\end{document}
+</screen>
+<para>To make your document portable across distributions and platforms you
+should avoid spaces in the file names. The tradition is to instead use
+dashes or underscores.  Nevertheless, for the name ‘<literal>amo amas amat</literal>’,
+this works under &tex; Live on GNU/Linux:
+</para>
+<screen>\documentclass{book}
+\includeonly{
+  "amo\space amas\space amat"
+  }
+\begin{document}
+\include{"amo\space amas\space amat"}
+\end{document}
+</screen>
+<para>and this works under MiK&tex; on Windows:
+</para>
+<screen>\documentclass{book}
+\includeonly{
+  {"amo amas amat"}
+  }
+\begin{document}
+\include{{"amo amas amat"}}
+\end{document}
+</screen>
+<indexterm role="cp"><primary>nested <literal>\include</literal>, not allowed</primary></indexterm>
+<para>You cannot use <literal>\include</literal> inside a file that is being included or
+you get ‘<literal>LaTeX Error: \include cannot be nested.</literal>’  The
+<literal>\include</literal> command cannot appear in the document preamble; you will
+get ‘<literal>LaTeX Error: Missing \begin{document}</literal>’.
+</para>
+<para>If a file that you <literal>\include</literal> does not exist, for instance if you
+<literal>\include{athiesm}</literal> but you meant <literal>\include{atheism}</literal>,
+then &latex; does not give you an error but will warn you ‘<literal>No file
+athiesm.tex.</literal>’  (It will also create <filename>athiesm.aux</filename>.)
+</para>
+<para>If you <literal>\include</literal> the root file in itself then you first get
+‘<literal>LaTeX Error: Can be used only in preamble.</literal>’  Later runs get
+‘<literal>TeX capacity exceeded, sorry [text input levels=15]</literal>’.  To fix
+this, you must remove the inclusion <literal>\include{root}</literal> but also
+delete the file <filename><replaceable>root</replaceable>.aux</filename> and rerun &latex;.
+</para>
 
 </sect1>
 <sect1 label="24.3" id="_005cinput">
@@ -11403,17 +15164,38 @@
 
 <para>Synopsis:
 </para>
-<screen>\input{<replaceable>file</replaceable>}
+<screen>\input{<replaceable>filename</replaceable>}
 </screen>
-<para>The <literal>\input</literal> command causes the specified <replaceable>file</replaceable> to be read
-and processed, as if its contents had been inserted in the current
-file at that point.
+<para>&latex; processes the file as if its contents were inserted in the
+current file.  For a more sophisticated inclusion mechanism see
+<link linkend="_005cinclude-_0026-_005cincludeonly">\include & \includeonly</link>.
 </para>
-<para>If <replaceable>file</replaceable> does not end in ‘<literal>.tex</literal>’ (e.g., ‘<literal>foo</literal>’ or
-‘<literal>foo.bar</literal>’), it is first tried with that extension (‘<literal>foo.tex</literal>’
-or ‘<literal>foo.bar.tex</literal>’).  If that is not found, the original <replaceable>file</replaceable>
-is tried (‘<literal>foo</literal>’ or ‘<literal>foo.bar</literal>’).
+<para>If <replaceable>filename</replaceable> does not end in ‘<literal>.tex</literal>’ then &latex; first tries
+the filename with that extension; this is the usual case.  If
+<replaceable>filename</replaceable> ends with ‘<literal>.tex</literal>’ then &latex; looks for the
+filename as it is.
 </para>
+<para>For example, this
+</para>
+<screen>\input{macros}
+</screen>
+<para>will cause &latex; to first look for <filename>macros.tex</filename>. If it finds
+that file then it processes its contents as thought they had been
+copy-pasted in.  If there is no file of the name <filename>macros.tex</filename> then
+&latex; tries the name <filename>macros</filename>, without an extension. (This may
+vary by distribution.)
+</para>
+<para>To make your document portable across distributions and platforms you
+should avoid spaces in the file names. The tradition is to instead use
+dashes or underscores.  Nevertheless, for the name ‘<literal>amo amas amat</literal>’,
+this works under &tex; Live on GNU/Linux:
+</para>
+<screen>\input{"amo\space amas\space amat"}
+</screen>
+<para>and this works under MiK&tex; on Windows:
+</para>
+<screen>\input{{"amo amas amat"}}
+</screen>
 
 </sect1>
 </chapter>
@@ -11422,38 +15204,124 @@
 
 
 
-<sect1 label="25.1" id="Tables-of-contents">
-<title>Tables of contents</title>
+<sect1 label="25.1" id="Table-of-contents-etc_002e">
+<title>Table of contents etc.</title>
 
 <indexterm role="cp"><primary>table of contents, creating</primary></indexterm>
 
 <indexterm role="fn"><primary>\tableofcontents</primary></indexterm>
 <indexterm role="fn"><primary>.toc file</primary></indexterm>
-<para>A table of contents is produced with the <literal>\tableofcontents</literal>
-command.  You put the command right where you want the table of
-contents to go; &latex; does the rest for you.  A previous run must
-have generated a <filename>.toc</filename> file.
-</para>
-<para>The <literal>\tableofcontents</literal> command produces a heading, but it does
-not automatically start a new page.  If you want a new page after the
-table of contents, write a <literal>\newpage</literal> command after the
-<literal>\tableofcontents</literal> command.
-</para>
 <indexterm role="fn"><primary>\listoffigures</primary></indexterm>
 <indexterm role="fn"><primary>\listoftables</primary></indexterm>
 <indexterm role="fn"><primary>.lof file</primary></indexterm>
 <indexterm role="fn"><primary>.lot file</primary></indexterm>
-<para>The analogous commands <literal>\listoffigures</literal> and <literal>\listoftables</literal>
-produce a list of figures and a list of tables (from <filename>.lof</filename> and
-<filename>.lot</filename> files), respectively.  Everything works exactly the same
-as for the table of contents.
+
+<para>Synopsis, one of:
 </para>
-<indexterm role="fn"><primary>\nofiles</primary></indexterm>
-<para>The command <literal>\nofiles</literal> overrides these commands, and
-<emphasis>prevents</emphasis> any of these lists from being generated.
+<screen>\tableofcontents
+\listoffigures
+\listoftables
+</screen>
+<para>Produce a table of contents, or list of figures, or list of tables.  Put
+the command in the input file where you want the table or list to
+go. You do not type the entries; for example, typically the table of
+contents entries are automatically generated from the sectioning
+commands <literal>\chapter</literal>, etc.
 </para>
+<para>This example illustrates the first command, <literal>\tableofcontents</literal>.
+&latex; will produce a table of contents on the book’s first page.
+</para>
+<screen>\documentclass{book}
+% \setcounter{tocdepth}{1}
+\begin{document}
+\tableofcontents\newpage
+  ...
+\chapter{...}
+  ...
+\section{...}
+  ...
+\subsection{...}
+  ...
+\end{document}
+</screen>
+<para>Uncommenting the second line would cause that table to contain chapter
+and section listings but not subsection listings, because the
+<literal>\section</literal> command has level 1.  See <link linkend="Sectioning">Sectioning</link> for level
+numbers of the sectioning units.  For more on the <literal>tocdepth</literal>
+see <link linkend="Sectioning_002ftocdepth">Sectioning/tocdepth</link>.
+</para>
+<para>Another example of the use of <literal>\tableofcontents</literal> is in <link linkend="Larger-book-template">Larger
+book template</link>.
+</para>
+<para>If you want a page break after the table of contents, write a
+<literal>\newpage</literal> command after the <literal>\tableofcontents</literal> command, as
+above.
+</para>
+<para>To make the table of contents &latex; stores the information in an
+auxiliary file named <filename><replaceable>root-file</replaceable>.toc</filename> (see <link linkend="Splitting-the-input">Splitting the
+input</link>).  For example, this &latex; file <filename>test.tex</filename>
+</para>
+<screen>\documentclass{article}
+\begin{document}
+\tableofcontents\newpage
+\section{First section}
+\subsection{First subsection}
+  ...
+</screen>
+<para>writes the following line to <filename>test.toc</filename>.
+</para>
+<screen>\contentsline {section}{\numberline {1}First section}{2}
+\contentsline {subsection}{\numberline {1.1}First subsection}{2}
+</screen>
+<para>The <literal>section</literal> or <literal>subsection</literal> is the sectioning unit.  The
+hook <literal>\numberline</literal> lets you to change how the information appears
+in the table of contents.  Of its two arguments, <literal>1</literal> or <literal>1.1</literal>
+is the sectioning unit number and <literal>First section</literal> or <literal>First
+subsection</literal> is the title.  Finally, <literal>2</literal> is the page number on which
+the sectioning units start.
+</para>
+<para>One consequence of this auxiliary file storage strategy is that to get the
+contents page correct you must run &latex; twice, once to store the
+information and once to get it.  In particular, the first time that you
+run &latex; on a new document, the table of contents page will be empty
+except for its ‘<literal>Contents</literal>’ header.  Just run it again.
+</para>
+<para>The commands <literal>\listoffigures</literal> and <literal>\listoftables</literal> produce a
+list of figures and a list of tables.  They work the same way as the
+contents commands; for instance, these work with information stored in
+<filename>.lof</filename> and <filename>.lot</filename> files.
+</para>
+<indexterm role="cp"><primary>package, <literal>babel</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>babel</literal> package</primary></indexterm>
 
+<indexterm role="cp"><primary>package, <literal>polyglossia</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>polyglossia</literal> package</primary></indexterm>
 
+<para>To change the header for the table of contents page do something like
+the first line here.
+</para>
+<screen>\renewcommand{\contentsname}{Table of contents}
+\renewcommand{\listfigurename}{Plots}
+\renewcommand{\listtablename}{Tables}
+</screen>
+<para>Similarly, the other two lines will do the other two.
+Internationalization packages such as <filename>babel</filename> or <filename>polyglossia</filename>
+will change the headers depending on the chosen base language.
+</para>
+<indexterm role="cp"><primary>package, <literal>tocloft</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>tocloft</literal> package</primary></indexterm>
+
+<indexterm role="cp"><primary>package, <literal>tocbibbind</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>tocbibbind</literal> package</primary></indexterm>
+
+<para>CTAN has many packages for the table of contents and lists of figures
+and tables.  One convenient one for adjusting some aspects of the
+default, such as spacing, is <filename>tocloft</filename>.  And, <filename>tocbibbind</filename>
+will automatically add the bibliography, index, etc. to the table of
+contents.
+</para>
+
+
 <sect2 label="25.1.1" id="_005caddcontentsline">
 <title><literal>\addcontentsline</literal></title>
 
@@ -11464,151 +15332,711 @@
 </para>
 <screen>\addcontentsline{<replaceable>ext</replaceable>}{<replaceable>unit</replaceable>}{<replaceable>text</replaceable>}
 </screen>
-<para>The <literal>\addcontentsline</literal> command adds an entry to the specified list
-or table where:
+<indexterm role="fn"><primary>\contentsline</primary></indexterm>
+<para>Add an entry to the file specified by <replaceable>ext</replaceable>.  Usually <replaceable>ext</replaceable> is
+one of <literal>toc</literal> for the table of contents, <literal>lof</literal> for the list of
+figures, or <literal>lot</literal> for the list of tables.
 </para>
+<para>The following will result in an ‘<literal>Appendices</literal>’ line in the table of
+contents.
+</para>
+<screen>\addcontentsline{toc}{section}{\protect\textbf{Appendices}}
+</screen>
+<para>It will appear at the same indentation level as the sections, will be in
+boldface, and will be assigned the page number associated with the point
+where it appears in the input file.
+</para>
+<para>The <literal>\addcontentsline</literal> command writes information to the file
+<filename><replaceable>root-name</replaceable>.<replaceable>ext</replaceable></filename>.  It writes that information as the
+text of the command
+<literal>\contentsline{<replaceable>unit</replaceable>}{<replaceable>text</replaceable>}{<replaceable>num</replaceable>}</literal>, where
+<literal><replaceable>num</replaceable></literal> is the current value of counter <literal><replaceable>unit</replaceable></literal>.  The
+most common case is the table of contents and there <replaceable>num</replaceable> is the
+page number of the first page of <replaceable>unit</replaceable>.
+</para>
+<para>This command is invoked by the sectioning commands <literal>\chapter</literal>,
+etc., and also by <literal>\caption</literal> inside a float environment.  But it is
+also used by authors.  For example, in a book to have the preface
+unnumbered, you may use the starred <literal>\chapter*</literal>.  But that does not
+put in table of contents information, so you can enter it manually, as
+here.
+</para>
+<screen>\chapter*{Preface}
+\addcontentsline{toc}{chapter}{\protect\numberline{}Preface}
+</screen>
+<para>In the <filename>.toc</filename> file &latex; will put the line <literal>\contentsline
+{chapter}{\numberline {}Preface}{3}</literal>; note the page number
+‘<literal>3</literal>’.
+</para>
+<!-- xx how hardwired are these values?  other unit names? -->
+
+<para>All of the arguments for <literal>\addcontentsline</literal> are required.
+</para>
 <variablelist><varlistentry><term><replaceable>ext</replaceable>
-</term><listitem><para>The filename extension of the file on which information is to be written,
-typically one of: <literal>toc</literal> (table of contents), <literal>lof</literal> (list of
-figures), or <literal>lot</literal> (list of tables).
+</term><listitem><para>Typically one of the strings <literal>toc</literal> for the table of contents,
+<literal>lof</literal> for the list of figures, or <literal>lot</literal> for the list of
+tables. The filename extension of the information file.
 </para>
 </listitem></varlistentry><varlistentry><term><replaceable>unit</replaceable>
-</term><listitem><para>The name of the sectional unit being added, typically one of the
-following, matching the value of the <replaceable>ext</replaceable> argument:
+</term><listitem><para>A string that depends on the value of the <replaceable>ext</replaceable> argument:
 </para>
 <variablelist><varlistentry><term><literal>toc</literal>
-</term><listitem><para>The name of the sectional unit: <literal>part</literal>, <literal>chapter</literal>,
-<literal>section</literal>, <literal>subsection</literal>, <literal>subsubsection</literal>.
-</para></listitem></varlistentry><varlistentry><term><literal>lof</literal>
+</term><listitem><para>For the table of contents, this is the name of a sectional unit:
+<literal>part</literal>, <literal>chapter</literal>, <literal>section</literal>, <literal>subsection</literal>, etc.
+</para>
+</listitem></varlistentry><varlistentry><term><literal>lof</literal>
 </term><listitem><para>For the list of figures: <literal>figure</literal>.
-</para></listitem></varlistentry><varlistentry><term><literal>lot</literal>
+</para>
+</listitem></varlistentry><varlistentry><term><literal>lot</literal>
 </term><listitem><para>For the list of tables: <literal>table</literal>.
 </para></listitem></varlistentry></variablelist>
 </listitem></varlistentry><varlistentry><term><replaceable>text</replaceable>
-</term><listitem><para>The text of the entry.
+</term><listitem><para>The text of the entry.  You must <literal>\protect</literal> any commands that are
+fragile (see <link linkend="_005cprotect">\protect</link>).
 </para></listitem></varlistentry></variablelist>
-<indexterm role="fn"><primary>\contentsline</primary></indexterm>
-<para>What is written to the <filename>.<replaceable>ext</replaceable></filename> file is the command
-<literal>\contentsline{<replaceable>unit</replaceable>}{<replaceable>text</replaceable>}{<replaceable>num</replaceable>}</literal>, where
-<literal><replaceable>num</replaceable></literal> is the current value of counter <literal><replaceable>unit</replaceable></literal>.
+<para>The <literal>\addcontentsline</literal> command has an interaction with
+<literal>\include</literal> (see <link linkend="_005cinclude-_0026-_005cincludeonly">\include & \includeonly</link>). If you use them at
+the same level, as with
+<literal>\addcontentsline{...}{...}{...}\include{...}</literal> then lines
+in the table of contents can come out in the wrong order.  The solution
+is to move <literal>\addcontentsline</literal> into the file being included.
 </para>
-<!-- xx how hardwired are these values?  other unit names? -->
+<para>If you use a <replaceable>unit</replaceable> that &latex; does not recognize, as here
+</para>
+<screen>\addcontentsline{toc}{setcion}{\protect\textbf{Appendices}}
+</screen>
+<para>then you don’t get an error but the formatting in the table of contents
+will not make sense.
+</para>
 
-
 </sect2>
 <sect2 label="25.1.2" id="_005caddtocontents">
 <title><literal>\addtocontents</literal></title>
 
 <indexterm role="fn"><primary>\addtocontents{<replaceable>ext</replaceable>}{<replaceable>text</replaceable>}</primary></indexterm>
 
-<para>The <literal>\addtocontents</literal>{<replaceable>ext</replaceable>}{<replaceable>text</replaceable>} command adds text
-(or formatting commands) directly to the <filename>.<replaceable>ext</replaceable></filename> file that
-generates the table of contents or lists of figures or tables.
+<para>Synopsis:
 </para>
+<screen>\addtocontents{<replaceable>ext</replaceable>}{<replaceable>text</replaceable>}
+</screen>
+<para>Add <replaceable>text</replaceable>, which may be text or formatting commands, directly to
+the auxiliary file with extension <replaceable>ext</replaceable>.  This is most commonly used
+for the table of contents so that is the discussion here, but this also
+applies to the list of figures and list of tables.
+</para>
+<para>This will put some vertical space in the table of contents after the
+‘<literal>Contents</literal>’ header.
+</para>
+<screen>\tableofcontents\newpage
+\addtocontents{toc}{\protect\vspace*{3ex}}
+</screen>
+<para>The <literal>\addtocontents</literal> command has two arguments.  Both are
+required.
+</para>
 <variablelist><varlistentry><term><replaceable>ext</replaceable>
-</term><listitem><para>The extension of the file on which information is to be written,
-typically one of: <filename>toc</filename> (table of contents), <filename>lof</filename> (list of
-figures), or <filename>lot</filename> (list of tables).
+</term><listitem><para>Typically one of: <filename>toc</filename> for the table of contents, <filename>lof</filename> for
+the list of figures, or <filename>lot</filename> for the list of tables.  The
+extension of the file holding the information.
 </para>
 </listitem></varlistentry><varlistentry><term><replaceable>text</replaceable>
-</term><listitem><para>The text to be written.
+</term><listitem><para>The text, and possibly commands, to be written.
 </para></listitem></varlistentry></variablelist>
+<para>The sectioning commands such as <literal>\chapter</literal> use the
+<literal>\addcontentsline</literal> command to store information.  This command
+creates lines in the <filename>.toc</filename> auxiliary file containing the
+<literal>\contentsline</literal> command (see <link linkend="_005caddcontentsline">\addcontentsline</link>).  In contrast,
+the command <literal>\addtocontents</literal> puts material directly in that file.
+</para>
+<para>The <literal>\addtocontents</literal> command has an interaction with
+<literal>\include</literal> (see <link linkend="_005cinclude-_0026-_005cincludeonly">\include & \includeonly</link>). If you use them at
+the same level, as with
+<literal>\addtocontents{...}{...}\include{...}</literal> then lines in the
+table of contents can come out in the wrong order.  The solution is to
+move <literal>\addtocontents</literal> into the file being included.
+</para>
 
 </sect2>
-</sect1>
-<sect1 label="25.2" id="Glossaries">
-<title>Glossaries</title>
+<sect2 label="25.1.3" id="_005cnofiles">
+<title><literal>\nofiles</literal></title>
 
-<indexterm role="cp"><primary>glossaries</primary></indexterm>
+<indexterm role="fn"><primary>\nofiles</primary></indexterm>
 
-<indexterm role="fn"><primary>\makeglossary</primary></indexterm>
-<para>The command <literal>\makeglossary</literal> enables creating glossaries.
+<para>Synopsis:
 </para>
-<indexterm role="fn"><primary>\glossary</primary></indexterm>
-<indexterm role="cp"><primary><filename>.glo</filename> file</primary></indexterm>
-<para>The command <literal>\glossary{<replaceable>text</replaceable>}</literal> writes a glossary entry for
-<replaceable>text</replaceable> to an auxiliary file with the <filename>.glo</filename> extension.
+<screen>\nofiles
+</screen>
+<para>Prevent &latex; from writing any auxiliary files.  The only output will
+be the <filename>.log</filename> and <filename>.pdf</filename> (or <filename>.dvi</filename>) files.  This command
+must go in the preamble.
 </para>
-<indexterm role="fn"><primary>\glossaryentry</primary></indexterm>
-<para>Specifically, what gets written is the command
-<literal>\glossaryentry{<replaceable>text</replaceable>}{<replaceable>pageno</replaceable>}</literal>, where
-<replaceable>pageno</replaceable> is the current <literal>\thepage</literal> value.
+<para>Because of the <literal>\nofiles</literal> command this example will not produce a
+<filename>.toc</filename> file.
 </para>
-<indexterm role="cp"><primary>glossary package</primary></indexterm>
-<para>The <literal>glossary</literal> package on CTAN provides support for fancier
-glossaries.
+<screen>\documentclass{book}
+\nofiles
+\begin{document}
+\tableofcontents\newpage
+\chapter{...}
+  ...
+</screen>
+<para>&latex; will not erase any existing auxiliary files, so if you insert
+the <literal>\nofiles</literal> command after you have run the file and gotten
+a <filename>.toc</filename> then the table of contents page will continue to show
+the old information.
 </para>
 
+</sect2>
 </sect1>
-<sect1 label="25.3" id="Indexes">
+<sect1 label="25.2" id="Indexes">
 <title>Indexes</title>
 
 <indexterm role="cp"><primary>indexes</primary></indexterm>
 
 <indexterm role="fn"><primary>\makeindex</primary></indexterm>
-<para>The command <literal>\makeindex</literal> enables creating indexes.  Put this in
-the preamble.
-</para>
 <indexterm role="fn"><primary>\index</primary></indexterm>
 <indexterm role="cp"><primary><filename>.idx</filename> file</primary></indexterm>
-<para>The command <literal>\index{<replaceable>text</replaceable>}</literal> writes an index entry for
-<replaceable>text</replaceable> to an auxiliary file named with the <filename>.idx</filename> extension.
+
+<para>This document has an index.
 </para>
-<indexterm role="fn"><primary>\indexentry</primary></indexterm>
-<para>Specifically, what gets written is the command
-<literal>\indexentry{<replaceable>text</replaceable>}{<replaceable>pageno</replaceable>}</literal>, where <replaceable>pageno</replaceable>
-is the current <literal>\thepage</literal> value.
+<screen>\documentclass{article}
+\usepackage{makeidx} \makeindex
+  ...
+\begin{document}
+  ...
+Recall Wilson's Theorem: \index{Wilson's Theorem}
+a number \( n>1 \) is prime if and only if the factorial of \( n-1 \)
+is congruent to \( -1 \) modulo~\( n \).
+  ...
+\printindex
+  ...
+</screen>
+<para>The <literal>\usepackage{makeidx}</literal> and <literal>\makeindex</literal> in the preamble
+bring in the relevant commands.
 </para>
+<para>Producing an index is a three stage process.  First, in the document
+body you declare index entries with the <literal>\index</literal> command
+(see <link linkend="_005cindex">\index</link>).  When you run &latex;, the <literal>\index</literal> writes its
+information to an auxiliary file <filename><replaceable>root-name</replaceable>.idx</filename>.  Next, to
+alphabetize and to do other manipulations you run an external command,
+typically <command>makeindex</command> or <command>xindy</command> (see <link linkend="makeindex">makeindex</link>).
+These output a file <filename><replaceable>root-name</replaceable>.ind</filename>.  Finally, you bring the
+information back into your document and typeset it with the
+<literal>\printindex</literal> command (see <link linkend="_005cprintindex">\printindex</link>).
+</para>
+<indexterm role="cp"><primary>package, <literal>showidx</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>showidx</literal> package</primary></indexterm>
+
+<indexterm role="cp"><primary>package, <literal>multind</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>multind</literal> package</primary></indexterm>
+
+<para>There are many packages that apply to indexing commands.  The
+<literal>showidx</literal> package causes each index entries to be shown in the
+margin on the page where the entry appears.  This can help in preparing
+the index.  The <literal>multind</literal> package supports multiple indexes.  See
+also the &tex; FAQ entry on this topic,
+<ulink url="http://www.tex.ac.uk/cgi-bin/texfaq2html?label=multind">http://www.tex.ac.uk/cgi-bin/texfaq2html?label=multind</ulink>.
+</para>
+
+
+<sect2 label="25.2.1" id="_005cindex">
+<title><literal>\index</literal></title>
+
+<indexterm role="cp"><primary>index entry</primary></indexterm>
+<indexterm role="fn"><primary>\index</primary></indexterm>
+
+<para>Synopsis:
+</para>
+<screen>\index{<replaceable>index-entry-string</replaceable>}
+</screen>
+<para>Declare an entry in the index.  This command is fragile
+(see <link linkend="_005cprotect">\protect</link>).
+</para>
+<para>For example, as described in <link linkend="Indexes">Indexes</link>, one way to get an index from
+what’s below is to compile the document with <literal>pdflatex test</literal>, then
+process the index entries with <literal>makeindex test</literal>, and then compile
+again with <literal>pdflatex test</literal>.
+</para>
+<screen>W~Ackermann (1896--1962).\index{Ackermann}
+  ...
+Ackermann function\index{Ackermann!function}
+  ...
+rate of growth\index{Ackermann!function!growth rate}
+</screen>
+<para>All three index entries will get a page number, such as ‘<literal>Ackermann,
+22</literal>’.  &latex; will format the second as a subitem of the first, on the
+line below it and indented, and the third as a subitem of the second.
+Three levels deep is as far as you can nest subentries.  (If you add
+<literal>\index{Ackermann!function!growth rate!comparison}</literal> then
+<command>makeindex</command> says ‘<literal>Scanning input file test.idx....done (4
+entries accepted, 1 rejected)</literal>’ and nothing appears in the index).
+</para>
+<para>If you enter a second <literal>\index</literal> with the same
+<replaceable>index-entry-string</replaceable> then you will get a single index entry with two
+page numbers (unless they happen to fall on the same page).  Thus,
+adding <literal>as for Ackermann.\index{Ackermann}</literal> later in the same
+document as above will give an index entry like ‘<literal>Ackermann, 22,
+151</literal>’.  Also, you can enter the index entries in any order, so for
+instance <literal>\index{Ackermann!function}</literal> could come before
+<literal>\index{Ackermann}</literal>.
+</para>
+<indexterm role="cp"><primary>index, page range</primary></indexterm>
+<para>Get a page range in the output, like ‘<literal>Hilbert, 23--27</literal>’, as here.
+</para>
+<screen>W~Ackermann (1896--1962).\index{Ackermann}
+  ...
+D~Hilbert (1862--1943)\index{Ackermann!Hilbert\(}
+  ...
+disapproved of his marriage.\index{Ackermann!Hilbert\)}
+</screen>
+<para>If the beginning and ending of the page range are equal then the system
+just gives a single page entry, not a range.
+</para>
+<para>If you index subentries but not a main entry, as with
+<literal>\index{Jones!program}</literal> and <literal>\index{Jones!results}</literal>, then
+the output is the item ‘<literal>Jones</literal>’ with no comma or page number,
+followed by two subitems, like ‘<literal>program, 50</literal>’ and ‘<literal>results,
+51</literal>’.
+</para>
 <indexterm role="cp"><primary>‘see’ and ‘see also’ index entries</primary></indexterm>
 <indexterm role="cp"><primary>index entries, ‘see’ and ‘see also’</primary></indexterm>
-<para>To generate a index entry for ‘bar’ that says ‘See foo’, use a
-vertical bar: <literal>\index{bar|see{foo}}</literal>.  Use <literal>seealso</literal>
-instead of <literal>see</literal> to make a ‘See also’ entry.
-</para>
 <indexterm role="fn"><primary>\seename</primary></indexterm>
 <indexterm role="fn"><primary>\alsoname</primary></indexterm>
-<para>The text ‘See’ is defined by the macro <literal>\seename</literal>, and ‘See also’
-by the macro <literal>\alsoname</literal>.  These can be redefined for other
-languages.
+<indexterm role="cp"><primary>package, <literal>babel</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>babel</literal> package</primary></indexterm>
+<indexterm role="cp"><primary>package, <literal>polyglossia</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>polyglossia</literal> package</primary></indexterm>
+
+
+<para>Generate a index entry that says ‘<literal>See</literal>’ by using a vertical bar
+character: <literal>\index{Ackermann!function|see{P\'eter's
+function}}</literal>.  You can instead get ‘<literal>See also</literal>’ with <literal>seealso</literal>.
+(The text ‘<literal>See</literal>’ is defined by <literal>\seename</literal>, and ‘<literal>See also</literal>’
+by <literal>\alsoname</literal>.  You can redefine these either by using an
+internationalization package such as <filename>babel</filename> or <filename>polyglossia</filename>,
+or directly as with <literal>\renewcommand{\alsoname}[1]{Also see
+#1}</literal>.)
 </para>
+<para>The ‘<literal>See</literal>’ feature is part of a more general functionality.  After
+the vertical bar you can put the name of a one-input command, as in
+<literal>\index{group|textit}</literal> (note the missing backslash on the
+<literal>\textit</literal> command) and the system will apply that command to the
+page number, here giving something like <literal>\textit{7}</literal>.  You can
+define your own one-input commands, such as
+<literal>\newcommand{\definedpage}[1]{{\color{blue}#1}}</literal> and then
+<literal>\index{Ackermann!function|definedpage}</literal> will give a blue page
+number (see <link linkend="Color">Color</link>).  Another, less practical, example is this,
+</para>
+<!-- credit Ian Thompson https://tex.stackexchange.com/a/272572/121234 -->
+<screen>\newcommand\indexownpage[1]{#1, \thepage}
+  ... Epimenides.\index{self-reference|indexownpage}
+</screen>
+<para>which creates an entry citing the page number of its own index listing.
+</para>
+<para>The two functions just described combine, as here
+</para>
+<screen>\index{Ackermann!function|(definedpage}
+  ...
+\index{Ackermann!function|)}
+</screen>
+<para>which outputs an index entry like ‘<literal>function, 23--27</literal>’ where the page
+number range is in blue.
+</para>
+<para>Consider an index entry such as ‘<literal>&#x03B1;-ring</literal>’.  Entering
+it as <literal>$\alpha$-ring</literal> will cause it to be alphabetized according to
+the dollar sign. You can instead enter it using an at-sign, as
+<literal>\index{alpha-ring@$\alpha$-ring}</literal>.  If you specify an entry
+with an at-sign separating two strings, <literal><replaceable>pos</replaceable>@<replaceable>text</replaceable></literal>,
+then <replaceable>pos</replaceable> gives the alphabetical position of the entry while
+<replaceable>text</replaceable> produces the text of the entry.  Another example is that
+<literal>\index{Saint Michael's College at SMC}</literal> produces an index entry
+‘<literal>SMC</literal>’ alphabetized into a different location than its spelling
+would naturally give it.
+</para>
+<para>To put a <literal>!</literal>, or <literal>@</literal>, or <literal>|</literal> character in an index
+entry, preceding it with a double quote, <literal>"</literal>.  (The double quote
+gets deleted before alphabetization.)
+</para>
+<indexterm role="cp"><primary>package, <literal>index</literal></primary></indexterm>
+<indexterm role="cp"><primary><literal>index</literal> package</primary></indexterm>
+
+<para>A number of packages on CTAN have additional functionality beyond that
+provided by <filename>makeidx</filename>.  One is <filename>index</filename>, which allows for
+multiple indices and contains a command
+<literal>\index*{<replaceable>index-entry-string</replaceable>}</literal> that prints the
+<replaceable>index-entry-string</replaceable> as well as indexing it.
+</para>
+<indexterm role="fn"><primary>\indexentry</primary></indexterm>
+<indexterm role="cp"><primary>idx file</primary></indexterm>
+<para>The <literal>\index</literal> command writes the indexing information to the file
+<filename><replaceable>root-name</replaceable>.idx</filename> file.  Specifically, it writes text of the
+command
+<literal>\indexentry{<replaceable>index-entry-string</replaceable>}{<replaceable>page-num</replaceable>}</literal>, where
+where <replaceable>page-num</replaceable> is the value of the <literal>\thepage</literal> counter.  On
+occasion, when the <literal>\printindex</literal> command is confused, you have to
+delete this file to start with a fresh slate.
+</para>
+<para>If you omit the closing brace of an <literal>\index</literal> command then you get a
+message like this.
+</para>
+<screen>Runaway argument?  {Ackermann!function
+!  Paragraph ended before \@wrindex was complete.
+</screen>
+
+</sect2>
+<sect2 label="25.2.2" id="makeindex">
+<title><command>makeindex</command></title>
+
+<indexterm role="cp"><primary>index, processing</primary></indexterm>
+<indexterm role="fn"><primary>makeindex</primary></indexterm>
 <indexterm role="cp"><primary><command>makeindex</command> program</primary></indexterm>
-<indexterm role="cp"><primary><command>xindy</command> program</primary></indexterm>
 <indexterm role="cp"><primary><filename>.ind</filename> file</primary></indexterm>
-<para>The generated <filename>.idx</filename> file is then sorted with an external
-command, usually either <command>makeindex</command>
-(<ulink url="http://mirror.ctan.org/indexing/makeindex">http://mirror.ctan.org/indexing/makeindex</ulink>) or (the
-multi-lingual) <command>xindy</command> (<ulink url="http://xindy.sourceforge.net">http://xindy.sourceforge.net</ulink>).
-This results in a <filename>.ind</filename> file, which can then be read to typeset
-the index.
+<indexterm role="cp"><primary><filename>.idx</filename> file</primary></indexterm>
+
+<para>Synopsis, one of:
 </para>
+<screen>makeindex <replaceable>filename</replaceable>
+makeindex -s <replaceable>style-file</replaceable> <replaceable>filename</replaceable>
+makeindex <replaceable>options</replaceable> <replaceable>filename0</replaceable> ...
+</screen>
+<para>Sort, and otherwise process, the index information in the auxiliary file
+<replaceable>filename</replaceable>.  This is a command line program.  It takes one or more
+raw index files, <filename><replaceable>filename</replaceable>.idx</filename> files, and produces the
+actual index file, the <filename><replaceable>filename</replaceable>.ind</filename> file that is input by
+<literal>\printindex</literal> (see <link linkend="_005cprintindex">\printindex</link>).
+</para>
+<indexterm role="cp"><primary><filename>.isty</filename> file</primary></indexterm>
+<indexterm role="fn"><primary>index, style file</primary></indexterm>
+<indexterm role="fn"><primary>makeindex, style file</primary></indexterm>
+<para>The first form of the command suffices for many uses.  The second allows
+you to format the index by using an <firstterm>index style file</firstterm>, a
+<filename>.isty</filename> file.  The third form is the most general; see the full
+documentation on CTAN.
+</para>
+<para>This is a simple <filename>.isty</filename> file.
+</para>
+<screen>% book.isty 
+%   $ makeindex -s book.isty -p odd book.idx
+% creates the index as book.ind, starting on an odd page. 
+preamble
+"\\pagestyle{empty}
+\\small
+\\begin{theindex}
+\\thispagestyle{empty}"
+
+postamble
+"\n
+\\end{theindex}"
+</screen>
+<para>The description here covers only some of the index formatting
+possibilities in <replaceable>style-file</replaceable>. For a full list see the documentation
+on CTAN.
+</para>
+<para>A style file consists of a list of pairs: <replaceable>specifier</replaceable> and
+<replaceable>attribute</replaceable>.  These can appear in the file in any order.  All of the
+<replaceable>attributes</replaceable> are strings, except where noted.  Strings are
+surrounded with double quotes, <literal>"</literal>, and the maximum length of a
+string is 144 characters.  The <literal>\n</literal> is for a newline and <literal>\t</literal>
+is for a tab.  Backslashes are escaped with another backslash,
+<literal>\\</literal>.  If a line begins with a percent sign, <literal>%</literal>, then it is a
+comment.
+</para>
+<variablelist><anchor id="makeindex-preamble"/><varlistentry><term><indexterm role="fn"><primary>preamble</primary></indexterm><literal>preamble</literal>
+</term><listitem><para>Preamble of the output file. Defines the context in which the index is
+formatted.  Default: <literal>"\\begin{theindex}\n"</literal>.
+</para>
+<anchor id="makeindex-postamble"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>postamble</primary></indexterm><literal>postamble</literal>
+</term><listitem><para>Postamble of the output file.  Default: <literal>"\n\n\\end{theindex}\n"</literal>.
+</para>
+<anchor id="makeindex-group-skip"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>group_skip</primary></indexterm><literal>group_skip</literal>
+</term><listitem><indexterm role="fn"><primary>\indexspace</primary></indexterm>
+<para>Traditionally index items are broken into groups, typically a group for
+entries starting with ‘<literal>a</literal>’, etc.  This specifier gives what is
+inserted when a new group begins.  Default: <literal>"\n\n \\indexspace\n"</literal>
+(<literal>\indexspace</literal> is a rubber length with default value <literal>10pt
+plus5pt minus3pt</literal>).
+</para>
+<anchor id="makeindex-letheadflag"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>lethead_flag</primary></indexterm><literal>lethead_flag</literal>
+</term><listitem><para>An integer.  It governs what is inserted for a new group or letter.  If
+it is 0 (which is the default) then other than <literal>group_skip</literal> nothing
+will be inserted before the group. If it is is positive then at a new
+letter the <literal>lethead_prefix</literal> and <literal>lethead_suffix</literal> will be
+inserted, with that letter in uppercase between them.  If it is negative
+then what will be inserted is the letter in lowercase.  The default
+is 0.
+</para>
+<anchor id="makeindex-lethead-prefix"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>lethead_prefix</primary></indexterm><literal>lethead_prefix</literal>
+</term><listitem><para>If a new group begins with a different letter then this is the prefix
+inserted before the new letter header.  Default: <literal>""</literal>
+</para>
+<anchor id="makeindex-lethead-suffix"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>lethead_suffix</primary></indexterm><literal>lethead_suffix</literal>
+</term><listitem><para>If a group begins with a different letter then this is the suffix
+inserted after the new letter header.  Default: <literal>""</literal>.
+</para>
+<anchor id="makeindex-item-0"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>item_0</primary></indexterm><literal>item_0</literal>
+</term><listitem><para>What is put between two level 0 items.  Default: <literal>"\n \\item
+"</literal>.
+</para>
+<anchor id="makeindex-item-1"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>item_1</primary></indexterm><literal>item_1</literal>
+</term><listitem><para>Put between two level 1 items.  Default: <literal>"\n \\subitem "</literal>.
+</para>
+<anchor id="makeindex-item-2"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>item_2</primary></indexterm><literal>item_2</literal>
+</term><listitem><para>put between two level 2 items.  Default: <literal>"\n \\subsubitem "</literal>.
+</para>
+<anchor id="makeindex-item-01"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>item_01</primary></indexterm><literal>item_01</literal>
+</term><listitem><para>What is put between a level 0 item and a level 1 item.
+Default: <literal>"\n \\subitem "</literal>.
+</para>
+<anchor id="makeindex-item-x1"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>item_x1</primary></indexterm><literal>item_x1</literal>
+</term><listitem><para>What is put between a level 0 item and a level 1 item in the
+case that the level 0 item doesn’t have any page numbers (as in
+<literal>\index{aaa|see{bbb}}</literal>).  Default: <literal>"\n \\subitem "</literal>.
+</para>
+<anchor id="makeindex-item-12"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>item_12</primary></indexterm><literal>item_12</literal>
+</term><listitem><para>What is put between a level 1 item and a level 2 item.
+Default: <literal>"\n \\subsubitem "</literal>.
+</para>
+<anchor id="makeindex-item-x2"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>item_x2</primary></indexterm><literal>item_x2</literal>
+</term><listitem><para>What is put between a level 1 item and a level 2 item, if the
+level 1 item doesn’t have page numbers.  Default: <literal>"\n
+\\subsubitem "</literal>.
+</para>
+<anchor id="makeindex-delim-0"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>delim_0</primary></indexterm><literal>delim_0</literal>
+</term><listitem><para>Delimiter put between a level 0 key and its first page
+number. Default: a comma followed by a blank, <literal>", "</literal>.
+</para>
+<anchor id="makeindex-delim-1"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>delim_1</primary></indexterm><literal>delim_1</literal>
+</term><listitem><para>Delimiter put between a level 1 key and its first page
+number. Default: a comma followed by a blank, <literal>", "</literal>.
+</para>
+<anchor id="makeindex-delim-2"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>delim_2</primary></indexterm><literal>delim_2</literal>
+</term><listitem><para>Delimiter between a level 2 key and its first page number. Default:
+a comma followed by a blank, <literal>", "</literal>.
+</para>
+<anchor id="makeindex-delim-n"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>delim_n</primary></indexterm><literal>delim_n</literal>
+</term><listitem><para>Delimiter between two page numbers for the same key (at any
+level). Default: a comma followed by a blank, <literal>", "</literal>.
+</para>
+<anchor id="makeindex-delim-r"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>delim_r</primary></indexterm><literal>delim_r</literal>
+</term><listitem><para>What is put between the starting and ending page numbers of a range.
+Default: <literal>"--"</literal>.
+</para>
+<anchor id="makeindex-line-max"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>line_max</primary></indexterm><literal>line_max</literal>
+</term><listitem><para>An integer.  Maximum length of an index entry’s line in the output,
+beyond which the line wraps.  Default: <literal>72</literal>.
+</para>
+<anchor id="makeindex-indent-space"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>indent_space</primary></indexterm><literal>indent_space</literal>
+</term><listitem><para>What is inserted at the start of a wrapped line.  Default:
+<literal>"\t\t"</literal>.
+</para>
+<anchor id="makeindex-indent-length"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>indent_length</primary></indexterm><literal>indent_length</literal>
+</term><listitem><para>A number.  The length of the wrapped line indentation.  The default
+<literal>indent_space</literal> is two tabs and each tab is eight spaces so the
+default here is <literal>16</literal>.
+</para>
+<anchor id="makeindex-page-precedence"/></listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>page_precedence</primary></indexterm><literal>page_precedence</literal>
+</term><listitem><para>A document may have pages numbered in different ways.  For example, a
+book may have front matter pages numbered in lowercase roman while main
+matter pages are in arabic.  This string specifies the order in which
+they will appear in the index.  The <command>makeindex</command> command supports
+five different types of numerals: lowercase roman <literal>r</literal>, and numeric
+or arabic <literal>n</literal>, and lowercase alphabetic <literal>a</literal>, and uppercase
+roman <literal>R</literal>, and uppercase alphabetic <literal>A</literal>.  Default:
+<literal>"rnaRA"</literal>.
+</para>
+</listitem></varlistentry></variablelist>
+<indexterm role="fn"><primary>xindy</primary></indexterm>
+<indexterm role="cp"><primary><command>xindy</command> program</primary></indexterm>
+<para>There are a number of other programs that do the job <command>makeindex</command>
+does.  One is <command>xindy</command>, which does internationalization and can
+process indexes for documents marked up using &latex; and a number of
+other languages.  It is is highly configurable, both in markup terms and
+in terms of the collating order of the text.  See the documentation on
+CTAN.
+</para>
+
+</sect2>
+<sect2 label="25.2.3" id="_005cprintindex">
+<title><command>\printindex</command></title>
+
+<indexterm role="cp"><primary>index, printing</primary></indexterm>
 <indexterm role="fn"><primary>\printindex</primary></indexterm>
-<indexterm role="cp"><primary>package, <literal>makeidx</literal></primary></indexterm>
-<indexterm role="cp"><primary><literal>makeidx</literal> package</primary></indexterm>
 
-<para>The index is usually generated with the <literal>\printindex</literal> command.
-This is defined in the <literal>makeidx</literal> package, so
-<literal>\usepackage{makeidx}</literal> needs to be in the preamble.
+<para>Synopsis:
 </para>
-<indexterm role="fn"><primary>\indexspace</primary></indexterm>
-<para>The rubber length <literal>\indexspace</literal> is inserted before each new
-letter in the printed index; its default value is ‘<literal>10pt plus5pt
-minus3pt</literal>’.
+<screen>\printindex
+</screen>
+<indexterm role="fn"><primary>\printindex</primary></indexterm>
+<para>Place the index into the output.
 </para>
-<indexterm role="cp"><primary>package, <literal>showidx</literal></primary></indexterm>
-<indexterm role="cp"><primary><literal>showidx</literal> package</primary></indexterm>
+<para>To get an index you must first include
+<literal>\usepackage{makeidx}\makeindex</literal> in the document preamble and
+compile the document, then run the system command <command>makeindex</command>,
+and then compile the document again.  See <link linkend="Indexes">Indexes</link> for further
+discussion and an example of the use of <literal>\printindex</literal>.
+</para>
 
-<para>The <literal>showidx</literal> package causes each index entries to be shown in
-the margin on the page where the entry appears.  This can help in
-preparing the index.
+</sect2>
+</sect1>
+<sect1 label="25.3" id="Glossaries">
+<title>Glossaries</title>
+
+<indexterm role="cp"><primary>glossary</primary></indexterm>
+<indexterm role="cp"><primary>glossaries</primary></indexterm>
+<indexterm role="cp"><primary>acronyms, list of</primary></indexterm>
+<indexterm role="fn"><primary>\makeglossary</primary></indexterm>
+<indexterm role="fn"><primary>\printglossaries</primary></indexterm>
+
+<para>Synopsis:
 </para>
-<indexterm role="cp"><primary>package, <literal>multind</literal></primary></indexterm>
-<indexterm role="cp"><primary><literal>multind</literal> package</primary></indexterm>
+<screen>\usepackage{glossaries} \makeglossaries
+  ...
+\newglossaryentry{<replaceable>label</replaceable>}{<replaceable>settings</replaceable>}  
+  ...
+\gls{<replaceable>label</replaceable>}.  
+  ...
+\printglossaries
+</screen>
+<para>The <filename>glossaries</filename> package allows you to make glossaries, including
+multiple glossaries, as well as lists of acronyms.
+</para>
+<para>To get the output from this example, compile the document (for instance
+with <literal>pdflatex filename</literal>), then run the command line command
+<literal>makeglossaries filename</literal>, and then compile the document again.
+</para>
+<screen>\documentclass{...}  
+\usepackage{glossaries} \makeglossaries
+\newglossaryentry{tm}{%
+  name={Turing machine},
+  description={A model of a machine that computes.  The model is simple
+               but can compute anything any existing device can compute.
+               It is the standard model used in Computer Science.},
+  }  
+\begin{document}  
+Everything begins with the definition of a \gls{tm}.  
+  ...
+\printglossaries
+\end{document}
+</screen>
+<para>That gives two things.  In the main text it outputs ‘<literal>... definition
+of a Turing machine</literal>’.  In addition, in a separate sectional unit headed
+‘<literal>Glossary</literal>’ there appears a description list.  In boldface it says
+‘<literal>Turing machine</literal>’ and the rest of the item says in normal type
+‘<literal>A model of a machine … Computer Science</literal>’.
+</para>
+<indexterm role="fn"><primary>\makeglossary</primary></indexterm>
+<indexterm role="fn"><primary>\printglossaries</primary></indexterm>
+<indexterm role="cp"><primary><filename>.glo</filename> file</primary></indexterm>
+<para>The command <literal>\makeglossary</literal> opens the file that will contain the
+entry information, <filename><replaceable>root-file</replaceable>.glo</filename>.  Put the
+<literal>\printglossaries</literal> command where you want the glossaries to appear
+in your document.
+</para>
+<para>The <filename>glossaries</filename> package is very powerful.  For instance, besides
+the commands <literal>\newglossaryentry</literal> and <literal>\gls</literal>, there are similar
+commands for a list of acronyms.  See the package documentations on
+CTAN.
+</para>
 
-<para>The <literal>multind</literal> package supports multiple indexes.  See also the
-&tex; FAQ entry on this topic,
-<ulink url="http://www.tex.ac.uk/cgi-bin/texfaq2html?label=multind">http://www.tex.ac.uk/cgi-bin/texfaq2html?label=multind</ulink>.
+
+<sect2 label="25.3.1" id="_005cnewglossaryentry">
+<title><literal>\newglossaryentry</literal></title>
+
+<indexterm role="cp"><primary>glossary, entries</primary></indexterm>
+<indexterm role="fn"><primary>\newglossaryentry</primary></indexterm>
+
+<para>Synopsis, one of: 
 </para>
+<screen>\newglossaryentry{<replaceable>label</replaceable>} 
+{ 
+  name={<replaceable>name</replaceable>}, 
+  description={<replaceable>description</replaceable>}, 
+  <replaceable>other options</replaceable>, ... 
+}
+</screen>
+<para>or
+</para>
+<screen>\longnewglossaryentry{<replaceable>label</replaceable>} 
+{ 
+  name={<replaceable>name</replaceable>}, 
+  <replaceable>other options</replaceable> ..., 
+} 
+{<replaceable>description</replaceable>}
+</screen>
+<para>Declare a new entry for a glossary.  The <replaceable>label</replaceable> must be unique for
+the document.  The settings associated with the label are pairs:
+<literal><replaceable>key</replaceable>=<replaceable>value</replaceable></literal>.
+</para>
+<para>This puts the blackboard bold symbol for the real numbers &#x211D; in the
+glossary.
+</para>
+<screen>\newglossaryentry{R}  
+{  
+  name={\ensuremath{\mathbb{R}}},  
+  description={the real numbers},  
+}
+</screen>
+<para>Use the second command form if the <replaceable>description</replaceable> spans more than one
+paragraph.
+</para>
+<para>For a full list of <replaceable>key</replaceable>s see the package documentation on CTAN but
+here are a few.
+</para>
+<variablelist><varlistentry><term><indexterm role="fn"><primary>name</primary></indexterm><literal>name</literal>
+</term><listitem><para>(Required.) The word, phrase, or symbol that you are defining.
+</para>
+</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>description</primary></indexterm><literal>description</literal>
+</term><listitem><para>(Required.) The description that will appear in the glossary.
+If this has more than one paragraph then you must use the second command
+form given in the synopsis.
+</para>
+</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>plural</primary></indexterm><literal>plural</literal>
+</term><listitem><para>The plural form of <replaceable>name</replaceable>.  Refer to the plural form using
+<literal>\glspl</literal> or <literal>\Glspl</literal> (see <link linkend="_005cgls">\gls</link>).
+</para>
+</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>sort</primary></indexterm><literal>sort</literal>
+</term><listitem><para>How to place this entry in the list of entries that the glossary holds.
+</para>
+</listitem></varlistentry><varlistentry><term><indexterm role="fn"><primary>symbol</primary></indexterm><literal>symbol</literal>
+</term><listitem><para>A symbol, such as a mathematical symbol, besides the name.
+</para>
+</listitem></varlistentry></variablelist>
 
+</sect2>
+<sect2 label="25.3.2" id="_005cgls">
+<title><literal>\gls</literal></title>
+
+<indexterm role="cp"><primary>glossary, entry reference</primary></indexterm>
+<indexterm role="fn"><primary>\gls</primary></indexterm>
+
+<para>Synopsis, one of: 
+</para>
+<screen>\gls{<replaceable>label</replaceable>}
+\glspl{<replaceable>label</replaceable>}
+\Gls{<replaceable>label</replaceable>}
+\Glspl{<replaceable>label</replaceable>}
+</screen>
+<para>Refer to a glossary entry.  The entries are declared with
+<literal>\newglossaryentry</literal> (see <link linkend="_005cnewglossaryentry">\newglossaryentry</link>).
+</para>
+<para>This
+</para>
+<screen>\newglossaryentry{N}{%
+  name={the natural numbers},
+  description={The numbers $0$, $1$, $2$, $\ldots$\@},
+  symbol={\ensuremath{\mathbb{N}}},
+  }  
+  ...
+Consider \gls{N}.
+</screen>
+<para>gives the output ‘<literal>Consider the natural numbers</literal>’.
+</para>
+<para>The second command form <literal>\glspl{<replaceable>label</replaceable>}</literal> produces the plural
+of <replaceable>name</replaceable> (by default it tries adding an ‘<literal>s</literal>’).  The third form
+capitalizes the first letter of <replaceable>name</replaceable>, as does the fourth form,
+which also takes the plural.
+</para>
+
+</sect2>
 </sect1>
 </chapter>
 <chapter label="26" id="Letters">
@@ -11620,7 +16048,7 @@
 <para>Synopsis: 
 </para>
 <screen>\documentclass{letter}
-\address{<replaceable>sender address</replaceable>}
+\address{<replaceable>senders address</replaceable>}   % return address
 \signature{<replaceable>sender name</replaceable>}
 \begin{document}
 \begin{letter}{<replaceable>recipient address</replaceable>}
@@ -11628,18 +16056,17 @@
   <replaceable>letter body</replaceable>
 \closing{<replaceable>closing text</replaceable>}
 \end{letter}
-...  more letters ...
+   ...
 \end{document}
 </screen>
 <para>Produce one or more letters.  
 </para>
 <para>Each letter is in a separate <literal>letter</literal> environment, whose argument
 <replaceable>recipient address</replaceable> often contains multiple lines separated with a
-double backslash (<literal>\\</literal>).  For example, you might have:
+double backslash, (<literal>\\</literal>).  For example, you might have:
 </para>
-<screen> \begin{letter}{Mr. Joe Smith \\ 
-      2345 Princess St. \\ 
-      Edinburgh, EH1 1AA}
+<screen> \begin{letter}{Ninon de l'Enclos \\
+                l'h\^otel Sagonne}
    ...
  \end{letter}
 </screen>
@@ -11652,15 +16079,15 @@
 contains multiple lines separated by a double
 backslash (<literal>\\</literal>).  &latex; will put the <replaceable>sender name</replaceable>
 under the closing, after a vertical space for the traditional
-hand-written signature; it also can contain multiple lines.
+hand-written signature.
 </para>
-<para>Each <literal>letter</literal> environment body begins with a required <literal>\opening</literal> command
-such as <literal>\opening{Dear Madam or Sir:}</literal>.  The <replaceable>letter body</replaceable>
-text is ordinary &latex; so it can contain everything from
-enumerated lists to displayed math, except that commands such as
-<literal>\chapter</literal> that make no sense in a letter are turned off.  Each
-<literal>letter</literal> environment body typically ends with a <literal>\closing</literal>
-command such as <literal>\closing{Yours,}</literal>.
+<para>Each <literal>letter</literal> environment body begins with a required
+<literal>\opening</literal> command such as <literal>\opening{Dear Madam or Sir:}</literal>.
+The <replaceable>letter body</replaceable> text is ordinary &latex; so it can contain
+everything from enumerated lists to displayed math, except that commands
+such as <literal>\chapter</literal> that make no sense in a letter are turned off.
+Each <literal>letter</literal> environment body typically ends with a
+<literal>\closing</literal> command such as <literal>\closing{Yours,}</literal>.
 </para>
 <indexterm role="fn"><primary>\\ for letters</primary></indexterm>
 <para>Additional material may come after the <literal>\closing</literal>.  You can say who
@@ -11668,13 +16095,13 @@
 Boss \\ the Boss's Boss}</literal>.  There’s a similar <literal>\encl</literal> command for
 a list of enclosures.  And, you can add a postscript with <literal>\ps</literal>.
 </para>
-<para>&latex;’s default is to indent the signature and the <literal>\closing</literal>
-above it by a length of <literal>\longindentation</literal>.  By default this is
+<para>&latex;’s default is to indent the sender name and the closing above it
+by a length of <literal>\longindentation</literal>.  By default this is
 <literal>0.5\textwidth</literal>. To make them flush left, put
 <literal>\setlength{\longindentation}{0em}</literal> in your preamble.
 </para>
 <para>To set a fixed date use something like
-<literal>\renewcommand{\today}{2015-Oct-12}</literal>.  If put in your preamble
+<literal>\renewcommand{\today}{1958-Oct-12}</literal>.  If put in your preamble
 then it will apply to all the letters.
 </para>
 <para>This example shows only one <literal>letter</literal> environment.  The three lines
@@ -11707,19 +16134,18 @@
 </para>
 <screen>\address{<replaceable>senders address</replaceable>}
 </screen>
-<para>Specifies the return address as it appears on the letter and on the
+<para>Specify the return address, as it appears on the letter and on the
 envelope.  Separate multiple lines in <replaceable>senders address</replaceable> with a
-double backslash <literal>\\</literal>.
+double backslash, <literal>\\</literal>.
 </para>
 <para>Because it can apply to multiple letters this declaration is often put
 in the preamble.  However, it can go anywhere, including inside an
 individual <literal>letter</literal> environment.
 </para>
-<para>This command is optional: without the <literal>\address</literal> declaration the
-letter is formatted with some blank space on top, for copying onto
-pre-printed letterhead paper.  (See <link linkend="Overview">Overview</link>, for details on your
-local implementation.)  With the <literal>\address</literal> declaration, it is
-formatted as a personal letter.
+<par