How to create dofollow link with flickr?

Is It possible to create dowfollow link in my Signatures in htxp://

I would imagine that the HTML syntax for the signature links in there are controlled by the forum template. Regardless, forum signature links are relatively worthless when it comes to helping your search engine rankings which would be the only purpose of dofollow on your signature links. Signature links are only good to getting actual human users to click through.