https://bugzilla.redhat.com/show_bug.cgi?id=2262410
--- Comment #34 from Akira TAGOH tagoh@redhat.com --- (In reply to Oleg Oshmyan from comment #33)
we can't guess a language from a character coverage completely, particularly if it is all-in-one font.
Yes; that's why glyph-coverage-based language lists aren't as useful as human-set fonts.conf language lists.
Well, I don't mean to that. Actually they are useful more than checking a pinpoint char coverage like libass does.
We can't guess a language representation coverage for a font from a character but if it is a set of characters, the guess would be somewhat better than single. "lang" guarantees minimal character coverage for the language. maybe the name "lang" may causes a confusion though.