The forums allow you to have a signature that appears after each post. It's useful for things like quotes, a link to your blog, a list of certifications you have passed, etc. You would do that by following the "My Profile" link at the top of any Saloon page, and then going to the "General Information about yourself" section.
The signature does not support HTML, and the only UBB tags you can use are " ... " to have something appears in italics, and " ... " to add links.
The moderators may edit/remove your signature or ask you to change it if need be. Common reasons are:
It isn't nice.
It advertises something we aren't comfortable with.