In the Catholic or Roman Catholic tradition, the term cathedral correctly applies only to a church that houses the seat of the bishop of a diocese. The abbey church of a territorial abbey serves the same function (that is, houses the seat of the abbot), but does not acquire the title. In any other jurisdiction canonically equivalent to a diocese but not canonically erected as such (prelature, vicariate, ordinariate, prefecture, apostolic administration), the church that serves this function is correctly called the "principal church" of the respective entity—though some have coopted the term cathedral anyway.