At the top of each short story, and on the table-of-contents post for each multi-chapter story, you'll find a series of little icons. These icons are taboo warnings. Their purpose is to tell you whether the story will make you uncomfortable. They're something of a compromise between detailed warnings, which can be spoilery, and simply saying the whole archive is for mature audiences, which doesn't help you locate the good gory porn. :D
The 'Mental Bad Touch' icon is a blanket trigger warning. It means there's something in there that makes people squirm. Things like torture, issues of sexual consent, or bad things happening to children or animals. I don't fetishize that stuff, but sometimes the plot requires it. If you have a very specific trigger, go ahead and ask on the contents post.