Roman Catholic" is a Protestant slur invented to make Catholics foreigners in their English-speaking countries.
What does history show instead?
The term "Roman", as in the "Roman Church", has been used since the Middle Ages – often connoting the local particular church of the Diocese of Rome – the first known occurrence of "Roman Catholic" as a synonym for "Catholic Church" was in communication with the Armenian Apostolic Church in 1208, after the East–West Schism.[3][4]
[I don't think the Armenians were big on English as a language!]
When I see "RCC" in a post, I skip over it quicker, since I know that the poster doesn't know what he is talking about.
RCC is a shorthand abbreviation for Roman Catholic church. I use it from time to time when I don't feel like typing out the whole thing.
I've seen your fellow Roman Catholics refer to non-Roman Catholics as "prots". Doesn't bother me at all.
I think you need to get off your high horse.
I'll again refer you the Baltimore Catechism.
You might want to do some homework on this topic.
“Roman Catholic” is correct when referring to the Roman Rite liturgy or to the Church prior to the partial reunification with some Orthodox, when a variety of liturgical rites were absorbed into the Church.