From
the Rules:
Tom wrote:
Every user is allowed to have a signature and an avatar. The signature, if present, should not contain any link to any external website. Simple text is preferred, but there can be images as long as they're reasonably small and not distracting.
You
can put a few userbars in your signature, just not too many of them
Besides, as I always say, there is no need to worry: if you do something wrong I will tell you in a gentle way, I will never ban anyone over something as simple as this
(and yes, I know some people have external links in their signatures, but as long as they are safe websites, I don't mind. "Should not" is different from "Must not")