Ship prefix

A ship prefix is a combination of letters, usually abbreviations, used in front of the name of a civilian or naval ship that has historically served numerous purposes, such as identifying the vessel's mode of propulsion, purpose, or ownership/nationality. In the modern environment, prefixes are cited inconsistently in civilian service, whereas in government service a vessel's prefix is seldom omitted due to government regulations dictating that a certain prefix be used. Today the common practice is to use a single prefix for all warships of a nation's navy, and other prefixes for auxiliaries and ships of allied services, such as coast guards. For example, the modern navy of Japan adopts the prefix "JS" – Japanese Ship. However, not all navies use prefixes. Among the blue-water navies, those of France, Brazil, China, Russia, Germany, and Spain do not use ship prefixes. NATO designations such as FS (French Ship), FGS (Federal German Ship), and SPS (Spanish Ship) can be used if needed.
Historically, prefixes for civilian vessels often identified the vessel's mode of propulsion, such as "MV" (motor vessel), "SS" (screw steamer; often cited as "steam ship"), or "PS" (paddle steamer).
These days, general civilian prefixes are used inconsistently, and frequently not at all. In terms of abbreviations that may reflect a vessel's purpose or function, technology has introduced a broad variety of differently named vessels onto the world's oceans, such as "LPGC" (liquified petroleum gas carrier), or "TB" (tug-boat), or "DB" (derrick barge). In many cases though, these abbreviations are used for purely formal, legal identification and are not used colloquially or in the daily working environment. Prefixes indicating a vessel's purpose (e.g., "RMS" for a Royal Mail ship or "RV" for research vessel) are also used.
Prefixes used for naval ships primarily reflect ownership, but may also indicate a vessel's type or purpose as a sub-set. Historically, the most significant navy was Britain's Royal Navy, which has usually used the prefix "HMS", standing for "His/Her Majesty's Ship". The Royal Navy also adopted nomenclature that reflected a vessel's type or purpose, e.g. HM Sloop. Commonwealth navies adopted a variation, with, for example, HMAS, HMCS, and HMNZS pertaining to Australia, Canada, and New Zealand, respectively.
In the early days of the United States Navy, abbreviations often included the type of vessel, for instance "USF" (United States Frigate), but this method was abandoned by President Theodore Roosevelt's Executive Order No. 549 of 1907, which made "United States Ship" (USS) the standard signifier for USN ships on active commissioned service. United States Navy prefixes officially only apply while a ship is in active commission, with only the name used before or after a period of commission and for all vessels "in service" rather than commissioned status.
However, not all navies used prefixes; this includes the significant navies of China, France and Russia.
From the 20th century onwards, most navies identify ships by letters or hull numbers (pennant numbers) or a combination of such. These identification codes were, and still are, painted on the side of the ship. Each navy has its own system: the United States Navy uses hull classification symbols, and the Royal Navy (e.g. 'D35' is destroyer 35 – HMS Dragon) and other navies of Europe and the Commonwealth use pennant numbers.
These tables list both current and historical prefixes known to have been used.
These prefixes are generally used for merchant vessels of any nationality.
The designations for United Kingdom ships applied at the time of the British Empire, before the establishment of separate navies for the Dominions.
In the Royal Netherlands Navy, "HNLMS" is the prefix in English, a translation of the Dutch original "Hr.Ms." or "Zr.Ms.". "Hr.Ms." should preferably not be used in English-language documents; nevertheless it is often seen on the World Wide Web. Until the moment a Dutch naval ship officially enters active service in the fleet, the ship's name is used without the prefix. Since King Willem-Alexander succeeded Queen Beatrix on 30 April 2013, "Hr.Ms." is replaced by "Zr.Ms.".
In Australia, the prefix NUSHIP is used to denote ships that have yet to be commissioned into the fleet.
In the United States, all prefixes other than "USS", "USNS", "USNV", and "USRC" were made obsolete in 1901, when President Theodore Roosevelt issued an Executive order fixing American naval nomenclature. USRC was replaced by USCGC when the Revenue Cutter Service merged with the United States Lifesaving Service to become the United States Coast Guard in 1915. USLHT also was replaced by USCGC when the United States Lighthouse Service became a part of the U.S. Coast Guard in 1939. USC&GS was replaced by NOAAS when the United States Coast and Geodetic Survey merged with other U.S. Government scientific agencies to form the National Oceanic and Atmospheric Administration (NOAA) in 1970. USFC was replaced by USFS when the United States Commission on Fish and Fisheries was reorganized as the U.S. Bureau of Fisheries in 1903, and USFS in turn was replaced in 1940 by US FWS when the Bureau of Fisheries merged with the United States Department of the Interior's Division of Biological Survey to form the Department of the Interior's Fish and Wildlife Service (which in 1956 was reorganized as the United States Fish and Wildlife Service). Seagoing ships Fish and Wildlife Service ships with the prefix US FWS that were transferred to NOAA when NOAA was created in 1970 switched to the NOAAS prefix.
A United States Navy ship that is not in active commission does not hold the title of United States Ship with simply the name without prefix used before and after commissioned service. Vessels, such as yard and harbor craft that are not commissioned and "in service" are officially referred to by name or hull number without prefix. Prior to commissioning, ships may be described as a pre-commissioning unit or PCU; for example, USS Gerald R. Ford was described as the "pre-commissioning unit (PCU) Gerald R. Ford" prior to her commissioning in 2017. Military Sealift Command (MSC) civilian crewed ships "in service" are given the prefix United States Naval Ship (USNS).
When it is stricken from the fleet list, a ship typically has the prefix "ex-" added to its name, to distinguish it from any active ships bearing the same name. For example, after USS Constellation (CV-64) was retired in 2003, she became referred to as ex-Constellation.
Fictional equivalents of tri-letter prefixes frequently appear in English-language science fiction works, applied to seafaring and spaceborne ships alike.