Most Catholic dioceses throughout the world are relatively similar. They have a bishop (or archbishop), a group of diocesan priests, and a number of parishes. They follow the Roman Rite of Catholicism and are generally pretty indistinct from each other. There are 2 "special" US dioceses that bear explanation, however!
Firstly, we have the Archdiocese for the Military Services, USA. This is a special one for us here at Saint Bridget of Sweden Parish, as our own Fr. Philip O'Neill is currently serving as a US Air Force Chaplain in this diocese on loan from the Archdiocese of Hartford! Technically, there are only 5 priests assigned to this Archdiocese: Archbishop Timothy Broglio and his four auxiliary bishops.
All other Catholic military chaplains are lent to the AMS by their home diocese, just like Fr. O'Neill. The priests are released from their home diocese for a period of military service with the understanding that they will return to continue their ministry afterwards. Praise God for the courage and dedication of our military chaplains of the AMS!
The second "special" diocese has a long name - The Ordinariate of the Chair of Saint Peter. This is a special "quasi-diocese" was instituted by Pope Benedict XVI in 2012. It serves as the home for Anglican priests and communities that seek to convert to Catholicism.
Because Anglicanism is one of the closer Protestant denominations to Catholicism, the pope thought it prudent to create a special pipeline for these priests and communities to enter the Catholic Church. They have also been granted special dispensation to continue observing certain parts of the Anglican Rite (properly blended with the Roman Rite) under a form of liturgy called the Anglican Use. Interesting, right?
Let us pray for all priests of the Ordinariate of the Chair of Saint Peter and all priests currently serving in the Archdiocese for the Military Services, USA. Let us also pray for an increase in vocations to the priesthood in general!