http://www.sil.org/iso639-3/documentation.asp?id=grc

I've added a few Ancient Greek releases, and I believe there's a few others in the database as well. When entered with Latin script, there's essentially no difference, but when entered with Greek script, there are differences (both case-conversion issues and differential accenting) from modern Greek. "Greek" works, but "Ancient Greek" would be more correct for these releases.

Note, Ancient Greek is specifically mentioned on http://wiki.musicbrainz.org/Language_Code ; when/if this ticket is addressed, that page will need a minor update.

Example release http://musicbrainz.org/release/dc7c8250-84be-4c08-abcc-a61f3c9e2f79.html