Probably. I think it says that near the bottom when you edit your signature. It probably requires a ticket or something to get it turned on. Just a guess
You can get the code by using the little symbols at the top of a reply window to put what you want, then copy and paste that into the sig area in your profile
Just for clarification...I THINK the code the sigs use is BB code. It's not HTML but is something that I've seen on several bulletin boards. There's a chance I'm using the wrong term for it!
some call it BB code, some call it UBB code -- it's a carry-over from Ultimate Bulletin Board. UBB history at http://en.wikipedia.org/wiki/Ultimate_Bulletin_Board (there was a time when i wrote UBB hacks/add-ons for fun - shhhh... dont tell anyone that i'm that much of a geek, 'k? )