clergy of other religions? For example, should a Catholic be expected to refer to a Protestant preacher as "Your reverence" or "Father so-and-so", or to a Protestant bishop as "Your excellency" or "Bishop so-and-so" if he obviously doesn't recognize the validity of that cleric's ordination?
Or the contrary: should a non-Catholic be expected to refer to a Catholic archbishop as "Your Grace" or to the Pope as "Your Holiness"?
Or the contrary: should a non-Catholic be expected to refer to a Catholic archbishop as "Your Grace" or to the Pope as "Your Holiness"?