Thread:User talk:CodeCat/Categories that have failed RFDO

I haven't tracked down the discussion, but both Category:Lojban nouns and Category:Lojban proper nouns were deleted as having failed RFDO. Aside from the merits of this individual case, I think we need to come up with a way of preventing Mewbot from creating categories that are validly formed, but shouldn't exist (to use an absurd example: Category:Chinese class 1 strong verbs). Maybe an exception list?