Exceptions to actual links after the forums backslash, such as index.php.
The nofollow puts the entered value after thehelper.net/forums/, so say if you put index.php:
[noparse][nofollow=index.php]Forum Index[/nofollow][/noparse]
Then it will actually lead to the index of this site...
[nofollow=index.php]Forum Index[/nofollow]
At least that's what it's supposed to do. However, it appears vB has a special use for that thing so I guess you can use it for local things like someone's profile without having to type [noparse]http://www.thehelper.net/forums/[/noparse] every time. Or, better yet, ignore it.
The rel="nofollow" tag tells Google not to assign page rank to that link. When the Google Spider comes to your site it is supposed to disallow any links tagged with a nofollow as far as giving Page Rank to.
Ghan has said he has fixed this. Monovertex please confirm this fix. This was only a problem with people that had signatures in the upper levels like not the special members but the respected members.