PDF version 1.7 by default?

[Ulrike Fischer]

Am Sun, 9 Feb 2025 02:10:41 +0100 schrieb Reinhard Kotucha via
tex-live:

 
> ok, I should have written 'released' instead of 'releases'.  But who
> recommended to make 1.7 the default?  And why?

The trigger was a draft currently discussed in a TWG of the pdf
association (about pdf/UA and pdf/A) where they recommend to use 1.7
for all "not 2.0" document, mostly as it makes life easier for
everyone if there are less versions around. It doesn't harm if a PDF
with a 1.5 feature sets claims it is 1.7 as PDF 1.7 includes all
features available in earlier PDF 1.x versions. But the other way
round is not true: the draft document reminded me that I wanted to
suggest 1.7 as default since quite some time as I see quite a lot
documents containing \pdfminorversion=7 to get around the warning
"PDF inclusion: found PDF version <1.6>, but at most version <1.5>
allowed" mentioned by Bruno. 

 > With this recommendation minor version numbers are meaningless.  Does
> version 2 require meaningful minor version numbers?  You mentioned 2.0
> already.

minor version are not meaningless, but since quite some time (since
the tex engines support pdf 2.0) they are only one part of the PDF
version, so to fully set that you should also set the major version:

\pdfminorversion=7 \pdfmajorversion=1

or use the commands provided by LaTeX.

-- 
Ulrike Fischer 
http://www.troubleshooting-tex.de/