That's because this is an old thread with the old rules. Signature restrictions were changed. You need to become a Jnr Member to have links in your signature now.
- Newbie: No styling (including links) allowed. Max 50 characters.
- Jr. Member: Links allowed. Max 150 characters.
- Member: Unlimited length.
- Full: Color allowed.
- Sr. Member: Size allowed
- Hero: Background color allowed
But I've seen newbies with links in their signature, but without the www.
Is it allowed?