I am not a protestant .. I am not a Catholic.
It seems to me to be problematic to describe a faith in terms of what it is not.
I realize we're not there yet, and it doesn't help as regards the article of this thread, but maybe one day it will just be "Christians."
Had I said, "I am not a Catholic, I am a Christian", we would have started WW3.
Why can't you oblique semanticists just accept that people whom are not Catholic, but attend a church, or are of a particular denomination are also not protestant ?