MyBB Community Forums

I have noticed on some forums you have to post so many posts before you are allowed a signature (stopping spam) can this be done on mybb, if so how?

Simplest way would be taking advantage of user groups and the promotions system. Make the default group not allowed to have signature and make a new group where they have permission to use signatures that members are automatically promoted to after X amount of posts.

I bhave a plugin to do this: http://www.mybbextras.com/showthread.php?tid=388

thank you all