nofollow in signatures and profiles

Is it possible to code a nofollow for signature and members custom profiles only?

I know we can select this option in the vbseo admin section but I want my forum links to follow and my members links to nofollow with a simple option rather than insert url's in a white or blacklist.

Certainly anything is possible to code

What you want to do does not exist in vbseo and you will need to have it custom coded.