The only latin-script based languages I know that use some accentuated letters not existing in precomposed form in unicode are Guarani (it uses "g with tilde") and Chechen (it uses several letters with a dot above, some exist in precomposed, but others don't).
There may be others, but I only know about those two.
I think orthographies of some African languages also need Latin letters with diacritics for which
Unicode/ISO 10646 have never assigned and will never assign precomposed fomts.
And, if we consider Old and Middle European languages, there are even more.
Needless to say, IPA(although not a language) is a very 'fertile' source of a number of accented letters.
(I believe there are some IPA letters linguists want to use that are not given separate
codepoints.)
I didn't and wouldn't count math symbols here although there are a lot of them
with Latin letter as base char.
Jungshik
-- Linux-UTF8: i18n of Linux on all levels Archive: http://mail.nl.linux.org/linux-utf8/
