From Wikipedia
Among Roman Catholics, a priest or deacon is the Reverend, various prelates below bishop along with Chaplains of His Holiness are the Reverend Monsignor, and any bishop is the Most Reverend. However, none of these are ever addressed as reverend alone. Instead, priests are addressed as "Father", prelates as "Monsignor", and bishops as "Excellency", though "Reverend" or "Most Reverend" may be appended to either where appropriate.
Yes, I know--but at least in THIS area, it's rarely used in 'common parlance' as opposed to formal documentation.