If you have several vbulletin licenses, and you only have very small web hosting. I can tell you a skill on how to share one set vbulletin code with multi vbulletin licenses.
add the following to config.php.
'configlocalhost.php',
'127.0.0.1'=>'config127.php',
);
$url = $arrays[$_SERVER['HTTP_HOST']];
include $url;
?>
and change the other 2 forums’ config.php to configlocalhost.php and config127.php.
that’s all.