vBullet?n's registration system...

[Sovereign]

I know that it uses "register.php" and that's about it. Could someone explain in detail how it works (need to know before I start tinkering with PHP-Nuke/vBulletin integration. Overall goal: NO MODIFYING VBULLETIN. Just make Nuke work around it, which in itself requires an understanding of how vB works...)