Yep, it's another rule. Actually, it's three new rules... isn't that great? But don't worry, chances are you won't have to change your behavior.

General Rules 8-10:

• Register with a character name, please! It's easier for everyone. Even if you don't know who you want to be yet, you should register with something other than "leonhart227."
• You may not PM other members with advertisements unless you've been an active member for thirty days.
• Don't join simply to advertise your forum. If all you do is send out a blanket PM saying "look at my board!", you'll be deleted.

And yes, this is partially because of a person who's joined in the past few days that has done little more than PM everyone (even my Aralyn account) saying "look at [insert name of FF forum]! Join!"

These really only apply to new members, so most of you don't have to worry about it.