[Koha] UDC and sign language

Ok, actual library question this time. This is for anyone out there that handles UDC cataloguing. We've got a copy of the abridged edition, and so far it's handled just about anything we've thrown at it, except this: Where does sign language (e.g. ASL, AUSLAN, NZSL etc) fit into the languages? I can't find it (or braille for that matter) in the Common Auxiliaries of Language anywhere! -custard.