An Apostolic administration in the Catholic Church is administrated by a prelate appointed by the pope to serve as the ordinary for a specific area. Either the area is not yet a diocese, or is a diocese, eparchy or similar permanent ordinariate that either has no bishop or, in very rare cases, has an incapacitated bishop.
The Roman Catholic Archdiocese of Mohilev was a territorial Latin rite division of the Roman Catholic Church, covering a significant western proportion of the territory of the Tsarist Russian empire.
The Armenian Catholic Ordinariate of Eastern Europe is an Ordinariate (quasi-diocese) of the Armenian Catholic Church for its faithful in certain Eastern European ex-Soviet countries without proper Ordinary for their particular church sui iuris.
An ecclesiastical region is a formally organised geographical group of dioceses, ecclesiastical provinces or parishes, without a proper Ordinary as such, in Catholic or Protestant Churches.
Ukrainian Catholic Eparchy of Vilnius and its successor Žyrovyci of the Ukrainians were the only eparchy in Lithuania of the Ukrainian Greek Catholic Church, but short-lived (1809-1828-1833).
The Ukrainian Catholic Eparchy of Lutsk–Ostroh was thrice an eparchy of the Ukrainian Greek Catholic Church in part of the Polish–Lithuanian Commonwealth and later an Eastern Catholic titular see (1921-73) but was abolished even as such. It was converted by joining the Union of Brest along with eparchies of Kiev, Polotsk, Pinsk, Kholm and Volodymyr.
The Ukrainian Catholic Eparchy of Volodymyr–Brest was an eparchy of the particular Ukrainian Greek Catholic Church sui iuris in parts of Ukraine and Belarus under Imperial Russian rule, from 1569 till 1833.