Mmm. Some authors seems to get away if the relationship it's ambiguous and if they don't show the girls or guys kiss/have sex. A lot of yuri is desguised as shoujo-ai I guess.
Whoah, this is way more substance than other chinese manhua I've ever read. Well, except Half-Prince, but that was years ago. So maybe the better phrase would be 'manhua I've ever read in this site?'