You're talking about the "Post Icons", I assume.



If you "hover" over them with your mouse, you'll get a little box telling what they all mean.

The most important one to remember is the "trigger icon" (Trig) for triggering topics. The other ones are just fun icons you can add to your post depending on your mood or what you're talking about in your post (whether that it's a poll, wanting attention, love/hugs, a question or whatnot).