i found it. Will quote you kirby:
I got a two signature limits (max. number of lines and max font size) in my board which do work quite good.
These are both adjustable in the Admin CP, 0 does mean no limit.
Maybe it is useful for others too, therefore I'm gonna post the code here.
In the User Profile Options section of the Admin CP create the settings
maxsiglines
maxsigfontsize
In Phrasegroup Front End Error Messages create the following phrses
sigtoomanylines
sigtoolargefont
In profile.php FIND
if ($vboptions['maximages'] != 0)
ABOVE that INSERT
// Signature Hacks
require_once('./includes/functions_bbcodeparse.php');
require_once('./includes/functions_misc.php');
// Signature Hacks
// Signature Limits Hack
// Check max. font size
if ($vboptions[maxsigfontsize] > 0) {
// Make sure user does not user too large fonts
$pattern = "/\[size=\+*0*[" . ($vboptions[maxsigfontsize]+1) . "-9]\].*\[\/size\]/si";
$pattern2 = "/\[size=\+0*[1-" . $vboptions[maxsigfontsize] . "]\].*\[\/size\]/si";
if (preg_match($pattern, $signature) or
preg_match($pattern2, $signature) or
preg_match("/\[size=\+*0*[1-9][0-9]+\].*\[\/size\]/si", $signature)
) {
$preview = 'true';
eval('$errors[] = "' . fetch_phrase('sigtoolargefont', PHRASETYPEID_ERROR) . '";');
}
}
// Check max. lines
$line_parsed_sig = parse_bbcode($signature);
$siglines = 0;
$siglines += fetch_character_count($line_parsed_sig, '<br');
$siglines += fetch_character_count($line_parsed_sig, '<blockquote');
$siglines += fetch_character_count($line_parsed_sig, '<pre');
$siglines += fetch_character_count($line_parsed_sig, '<center');
if (preg_match("/\<blockquote\>(.*)\<\/blockquote\>/si", $line_parsed_sig, $matches)) {
$siglines += preg_match_all("/\n/si", $matches[0], $lines)+1;
}
if ($vboptions[maxsiglines] > 0 and $siglines > $vboptions[maxsiglines]-1) {
$preview = 'true';
eval('$errors[] = "' . fetch_phrase('sigtoomanylines', PHRASETYPEID_ERROR) . '";');
}
// Signature Limits Hack
Please note that this does not affect current signatures.