Some considerable discussions have taken place as to whether it should be called the "Union Jack" or the "Union Flag."
This latter is the name usually given in the Official Regulations respecting the official use of a three-crossed flag of this description. There is in the navy the rank of "Admiral of the Fleet," corresponding to the rank of Field Marshal in the army. The Admiralty Regulations state that the proper flag of an Admiral of the Fleet is the "Union Flag," to be worn at the top masthead, and an Admiralty memorandum further states: "A Jack is a flag to be flown only on the 'Jack' staff, _i.e._, a staff on the bowsprit or forepart of the ship."
The difference in name of the same flag when carried on a ship would appear to indicate a difference in size appropriate to the different positions.
In the order in Council[172] directing what flags are to be used by diplomatic and consular officers, it is stated: "The flag to be used by Her Majesty's consular officers ashore to distinguish their residences is the Union flag."
[172] Order in Council, 7th August, 1869.
There is, however, another official name of this flag given in official instructions which must be noticed.
The Military Regulations (1899) order to be displayed afloat, by generals and other military officers commanding stations, as their distinguishing flags, "the Union, bearing in the centre as a distinguishing mark the Royal Initials, surrounded by a garland on a blue shield and surmounted by a crown." For Commissioners and Consuls-general, "the Union, with the Royal Arms in the centre, on a white shield, surrounded by a green garland."
This same name "Union" is also given in directions respecting this flag when included as a part of a larger flag.
The Admiralty Instructions directing what Ensign is to be worn by all ships of the Royal Navy in commission state that they shall "bear a White Ensign with the Red St. George's cross, and the Union in the upper canton."
The Foreign Office Regulations direct that "consular officers when embarked in boats or other vessels shall use the Blue Ensign with the Royal Arms in the centre of the fly of the flag, that is, in the centre of that between the Union and the end of the flag."