Stuff playing to the reader's kinks and fetishes. Rape fantasies, incest stories, snuff, whatever. . . Hardcore emotional twistiness. Anonymous sex, characters in warped, unhealthy relationships, badboys who are genuinely BAD, not just misunderstood. Anything that would draw fire from other slash lists.
Some fandoms are kinkier than others.
Some of you may be discussing the same things here you do on other lists. Some may be putting relatively tame stuff up because you're in an extremely whitebread fandom. Check out the Slash Kink Rules and Frequently Asked Questions page. E-mail the webmaster.