Royal dukedoms in the United Kingdom
In the British peerage, a royal duke is a member of the British royal family, entitled to the titular dignity of prince and the style of "His Royal Highness" who holds a dukedom. Dukedoms are the highest titles in the British roll of peerage and the holders of these particular dukedoms are Princes of the Blood Royal. The holders of the dukedoms are royal not the titles themselves. They are titles created and bestowed on legitimate sons and male-line grandsons of the British monarch, usually upon reaching their majority or marriage. The titles can be inherited but cease to be called "royal" once they pass beyond the grandsons of a monarch. As with any peerage, once the title becomes extinct, it may subsequently be recreated by the reigning monarch at any time.
Royal Army Chaplains' Department
Chaplains are the only British Army officers who do not carry standard officer ranks. They are officially designated Chaplain to the Forces (CF) (e.g. "The Reverend John Smith CF"). They do, however, have grades which equate to the standard ranks and wear the insignia of the equivalent rank. Chaplains are usually addressed as "Padre" , never by their nominal military rank.The senior Church of England Chaplain is ranked within the church hierarchy as an Archdeacon – he or she holds the appointment of Archdeacon for the Army whether or not he or she is also the Chaplain-General. The Senior Roman Catholic Chaplain (usually a CF1) is sometimes ranked as a monsignor.