So what I may consider hard, you may consider yaoi, or vice versa.

Normal/Gag : A parody of the series. No male x male relationships at all.
Shounen Ai : Male x Male relations hinted at. May just involve feelings, or have embraces and/or kisses.
Light Yaoi : A little more than just kisses/embraces. Prolonged making out, etc.
Yaoi : Actual sexual relations, whether implied or portrayed.
Hard Yaoi : Prolonged or graphic sexual relations.

Rating is based on both my personal opinion and on the rating the doujinka/circle themselves labled the doujinshi with.
(As I have not flipped through all the doujinshi, I may go by the "For Adults only" or "For 18+" that they slap on the covers and thus label it "hard".)

There are often occasions where I may label a doujinshi as being between 2 ratings (such as Gag/Shounen Ai or Yaoi-Hard Yaoi) that means it can be both or either rating.

*Please note that even hard yaoi may be censored by white bands or pixelation.

For all doujinshi labeled "Hard", please be prepared to email or fax in verification of age upon request.