From what I understand you are allowed to post art work with nudity if it is tasteful.

In my experience with hentai . . . it ususally isn't 'tasteful'. xD! But, I've posted pictures with exposed breasts before but it was an innocent picture for the sake of art work. =/ You'd be better off with someone else answering so I'd wait a little while for someone with a title to answer. Try PMing a Cid's Knight or something first for a quicker response.