The key principle here is that there is no central control. There is central agreement on doctrine, and each peer member helps prevent the others from taking over. Anyone who rejects the doctrine is, by definition, not a member. There needs to be a small office that is the holder of the common information, but it is not itself a member, nor does it have decision making powers. We believe that the key concept here is that the central group maintains a coherent set of information, but does not have the authority to change what it maintains, nor to make rulings about who can or cannot join.
Membership is open to anybody who agrees to adhere to the rules and who pays the fee.
A fee is crucial to a scheme like this because it prevents frivolous memberships and it is a means of funding ROOT Zone operations. As stated, this is best done with a customer coop where the customers are the collected set of TLD registries. Remember that the InterNIC currently performs all three functions. Splitting up the work is probably a good idea just to provide for more scalability. This structure could easily accommodate stakeholders groups under all three of these organizations.