Remove vB version number

vB does a great job with security, but what if you're not around to install the patch, or you overlook it? Security flaws are usually version specific, and detailed information is posted on the web on how to exploit flaws. If the flaw is for your version, you're making yourself a target by displaying your version number. It can be easily removed without violating your vB license.
http://www.vbulletin.com/forum/showthread.php?t=144248

Thanks for the resource Buffaloed.