I've read, on these very threads, the claim that protestantism is a mass of disunity comprised of 30,000+ denominations. I'm curious what a denomination is defined as. Is it a self governing church? Is it a church that maintains a jurisdiction (semi-autonomous)? I'm just seeking what rc's define as a denomination to justify the claim there are 30,000+ protestant denominations. Now, that said, if we can get past that question, what statistical data base do rc's refer to when they claim there are 30,000+ protestant denominations. There must be an authoritative resource that has compiled such data and I'm curious to see just who/what that is for rc's and how dependable it is as a resource.