do you know "Roman Catholic" called "Roman Catholic" not "Catholic only"?

Roman Catholicism has a "Roman" tag in it because Catholics recognize that its highest leader (the pope) is the successor of Peter, who in turn is recognized as the first leader of Christians in the Roman Empire.

Roman Catholic history dated back to the early years of St. Peter's tenure as Vicar of Jesus Christ.

It is called Roman Catholic because we are following the rules and rituals established by the Pope, which we recognized as head of the Universal Church. The Roman Catholic rituals followed the Latin rites which are slightly different from other Catholic's sister churches in European continent.