The AMA is the only community-based organization I know of. The majority of hobbyists are not members. They have a whole slew of rules in addition to the FAA's rules.
The AMA _likes_ to call themselves that but it really does not mean anything. Along those lines _I_ could call myself a "community-based organization and make up all kinds of stuff. The question then is if that organization actually has any rights to dictate your actions while flying. If I'm on your land and you want to tell me what I can and cannot do while in your land, fine. Recourse is to ask me to leave. This verbage is about as vague as you can get. It creates a door and no one knows what is on the otherside. Citys and towns see this as a means to control airspace in their area. I'm no so sure that is even legal.