[Xenon]

wouldn't be such a problem

add a new field to the usertable called isallowedsig default='1'

then just add an editfield in your admin-cp to change it from 0/1
nowhere else, just in admincp.

then in newreply.php find this:

PHP Code:

    if ($signature) {
      $post['signature'] = bbcodeparse($bbuserinfo['signature'],0,$allowsmilie);
      eval("\$post[signature] = \"".gettemplate("postbit_signature")."\";");
      $previewmessage.=$post['signature'];
    } 


and replace it with this:

PHP Code:

    if ($signature and $bbuserinfo[isallowedsig]) {
      $post['signature'] = bbcodeparse($bbuserinfo['signature'],0,$allowsmilie);
      eval("\$post[signature] = \"".gettemplate("postbit_signature")."\";");
      $previewmessage.=$post['signature'];
    } 


you surely want to add that lines small modificated to editpost.php and newthread.php also.

i haven't tested, but it should work.

it just disables new signatures, signatures in old posts aren't infected
run a query if you want to do it for old posts to