package vs. format?

[K. Berry]

Just to clarify our examples a bit: babel is a package, right, not a format?
Ditto amslatex? (amslatex used to be either one, but now it's just a
latex package, right?)

I added this text to try to define these terms a bit more clearly:

    The \abbr{TDS} specifies that macros are stored in separate directories,
    segregated by format and package, a `package' here being simply one or
    more {\TeX} input files generally containing only macro definitions, and
    a `format' being a usefully \path|\dump|-able package.

Actually, it might be good to use a different term for the macro
\replaceable{package}, since it's at odds with our (traditional) use of
`package' elsewhere, but I can't think of anything decent.