Hi Daniel,
> I am trying to make myself clear: I would like to know if it wouldn't be
> possible to employ a custom
> Unicode hyphenation rules/pattern file also for Pdflatex/Babel when the text
> there is Unicode, too
That shouldn't be necessary: the patterns that are presented to pdfTeX are
encoded in some *font* encoding, distinct from the input encoding that you use
in your document. The inputenc and fontenc packages take care of mapping the
code positions from the input encoding to the font encoding, be it UTF-8 or an
8-bit encoding. As far as the patterns are concerned, they're always encoded
in UTF-8 in the different hyph-<lang>.tex, and are converted on the fly when
input by pdfTeX, at format generation time, to whatever font encoding is
appropriate for the language at hand. The inputenc / fontenc packages then do
the job for you, and you can use any encoding you wish in your document.
However, I'm going to venture a wild guess and assume that the language
you're interested in is Sanskrit, a language which actually has patterns
disabled for pdfTeX, because we couldn't determine what font encoding was
appropriate when the patterns were submitted: for the vast majority of
languages that had patterns when Mojca and I took over work on hyphenation
files three years ago, there was one single 8-bit encoding, that was used by
both the pattern file and the Babel support files. Several languages, though,
have been added in the mean time, including Sanskrit, that had no dedicated
8-bit encoding that we could use(*). We thus decided to make them available
for Unicode-aware TeX engines only; hence, you don't have access to them from
pdfTeX. But if you have a reason to want to use them, we'll gladly make them
available as well. That won't be a problem at all; we only never considered
the issue because we didn't think it would come up -- Mojca, what do you think?
Arthur
(*) Note that packages to typeset Devanagari in TeX, as well as several other
Indic scripts, have existed for a long time, but they didn't have any
hyphenation patterns attached. These have only be added recently from
different contributors, and when Mojca found out that OpenOffice shipped many
pattern files for modern Indian languages. All the files were encoded using
UTF-8.
