In 6.2, you could remove the call to do_markup() in changebasic.php:
// ----------------------- <br />// Allow markup in the bio <br /> $Bio = $html -> do_markup($Bio); <br /> [:"red"]$Signature = $html -> do_markup($Signature);[/]
In 6.0.3, you could remove the call to do_markup() in addpost.php:
// ----------------------------- <br />// Always markup the signature <br /> $printsig = $user['U_Signature']; <br /> [:"red"]$printsig = $html -> do_markup($printsig);[/]
That doesn't prevent users from using markup in their signatures, but it prevents the markup from being translated to HTML.
