A ship prefix is a combination of letters, usually abbreviations, used in front of the name of a civilian or naval ship.
Prefixes for civilian vessels may either identify the type of propulsion, such as "SS" for steamship, or purpose, such as "RV" for research vessel. Civilian prefixes are often used inconsistently, and frequently not at all. Sometimes a slash is used to separate the letters, as in "M/S".
Naval prefixes came into use as abbreviations for longer titles, such as "His/Her Majesty's Ship" in the Royal Navy, abbreviated "H.M.S" and then "HMS". Earlier uses often included the type of vessel, as for instance "U.S.F." ("United States Frigate") for frigates of the United States Navy. 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.
The use of ship prefixes is not universal; in particular neither the Third Reich's Kriegsmarine nor the Imperial Japanese Navy seem to have used prefixes, although "DKM" and "HIJMS" respectively are often seen in English works. Occasionally writers will prefix a ship's name with an abbreviation of its nationality in their own language, such as "IJN" for Teikoku Nihon Kaigun, but that usage is deprecated.
In the 20th century, naval ships are often further identified by hull classification symbols, hull numbers, and pennant numbers, in a format specific to each navy.
Table of ship prefixes
This table lists both current and historical prefixes known to have been used.
| Country | Service | Prefix | Meaning | |
|---|---|---|---|---|
| generic | all | DSV | Deep Submergance Vessel | |
| generic | all | MS | Motor Ship | |
| generic | all | MSY | Motor Sailing Yacht | |
| generic | all | MT | Motor Tanker | |
| generic | all | MV | Motor Vessel | |
| generic | all | NS | Nuclear Ship | |
| generic | all | PS | Paddle Steamer | |
| generic | all | RV | Research Vessel | |
| generic | all | SS | Steam Ship | |
| generic | all | SV | Sailing Vessel | |
| generic | all | TS | Turbine Steamer | |
| Argentina | Argentine Navy | ARA | Armada de la Republica Argentina | |
| Australia | Royal Australian Navy | HMAS | His/Her Majesty's Australian Ship | |
| Bahamas | Bahamian Defense Force | HMBS | His/Her Majesty's Bahamian Ship | |
| Bangladesh | Bangladesh Navy | BNS | Bangladesh Naval Ship | |
| Barbados | Barbadan Defence Force | HMBS | His/Her Majesty's Barbadian Ship | |
| Belgium | Belgian Navy | BNS | Belgium Naval Ship (NATO prefix) | |
| Canada | Canadian Forces Maritime Command | HMCS | His/Her Majesty's Canadian Ship | |
| Canada | Canadian Coast Guard | CCGS | Canadian Coast Guard Ship | |
| Canada | Canadian Coast Guard | CCGC | Canadian Coast Guard Cutter | |
| Colombia | Armada Nacional | ARC | Armada de la Republica de Colombia | |
| Confederate States of America | Confederate States Navy | CSS | Confederate States Ship | |
| Denmark | Royal Danish Navy | HDMS (Danish: KDM) | His/Her Danish Majesty's Ship (Danish: Kongelige Danske Marine) | |
| Ecuador | ?? | BAE | Buque de la Armada de Ecuador | |
| Fiji | ?? | RFNS | Republic of Fiji Naval Ship | |
| France | French Navy | FS | French Ship (NATO designation); France does not use prefixes internally | |
| German Empire | Kaiserliche Marine | SM U-## | Seiner Majestät Unterseeboot | |
| German Empire | Kaiserliche Marine | SMS | Seiner Majestät Schiff | |
| Germany | Bundesmarine | FGS | Federal German Ship (NATO designation) | |
| Greece | Hellenic Navy | HS | Hellenic Ship (NATO designation) | |
| Guyana | ?? | GDFS | Guyanan Defense Forces Ship | |
| India | Indian Navy (pre-Republic) | HMINS | His/Her Majesty's Indian Naval Ship | |
| India | Indian Navy | INS | Indian Naval Ship | |
| Ireland | Irish Naval Service | LE | Long Éireannach — Irish ship | |
| Israel | Israeli Navy | INS | Israeli Naval Ship | |
| Japan | Imperial Japanese Navy | HIJMS | His Imperial Japanese Majesty's Ship | |
| Japan (after WWII) | Japanese Maritime Self Defense Force | JDS | JMSDF Defense Ship | |
| Kenya | ? | KNS | Kenyan Naval Ship | |
| Malaysia | Royal Malaysian Navy | KD | Kapal Di-Raja — Royal Ship | |
| Netherlands | Royal Netherlands Navy | HNLMS (Dutch: Hr.Ms. or Zr.Ms.) | His/Her Majesty's Netherlands Ship (Dutch: Harer Majesteits or Zijner Majesteits) | |
| New Zealand | Royal New Zealand Navy | HMNZS | His/Her Majesty's New Zealand Ship | |
| Nigeria | ? | NNS | Nigerian Naval Ship | |
| Norway | Royal Norwegian Navy | HNoMS (Norwegian: KNM) | Kongelige Norske Marine | |
| Norway | Norwegian Coast Guard | KV | Kystvakt | |
| Oman | ? | SNV | Sultanate Naval Vessel | |
| Pakistan | Pakistani Navy | PNS | Pakistani Naval Ship | |
| Papua New Guinea | ? | HMPNGS | Her Majesty's Papua New Guinea Ship | |
| Peru | Peruvian Navy | BAP | Buque Armada Peruana | |
| Philippines | Philippine Navy | BRP | Barka ng Republika ng Pilipinas | |
| Poland | Polish Navy | ORP | Polish Republic Naval Ship
(Polish: | |
| Portugal | Marinha de Guerra Portuguesa | NRP | Portuguese Republic Ship (Navio da República Portuguesa) | |
| Saudi Arabia | Saudi Navy | HMS | His Majesty's Ship — the same as the Royal Navy | |
| Singapore | Republic of Singapore Navy | RSS | Republic of Singapore Ship | |
| South Africa | South African Navy | SAS | South African Ship | |
| Spain | Armada Espanola | SPS | Spanish Naval Ship | |
| Sri Lanka | Sri Lanka Navy | SLNS | Sri Lanka Naval Ship | |
| Sweden | Royal Swedish Navy | HMS | His Majesty's Ship — the same as the Royal Navy | |
| Thailand | Royal Thai Navy | HTMS | His Thai Majesty's Ship | |
| Turkey | Turkish Navy | TCG | Türkiye Cumhuriyeti Gemisi | |
| Trinidad & Tobago | ? | TTS | Trinidad & Tobago Ship | |
| United Kingdom | Ships carrying mail | RMS | Royal Mail Steamer | |
| United Kingdom | Royal Fleet Auxiliary | RFA | Royal Fleet Auxiliary | |
| United Kingdom | Hospital ships | HMHS | His/Her Majesty's Hospital Ship | |
| United Kingdom | Royal Navy | HMAV | His/Her Majesty's Armed Vessel | |
| United Kingdom | Royal Navy | HMS | His/Her Majesty's Ship | |
| United Kingdom | Royal Navy | HMY | His/Her Majesty's Yacht | |
| United Kingdom | Royal Navy | HBMS | His/Her Britannic Majesty's Ship (archaic) | |
| United Kingdom | Royal Navy | HMT | His/Her Majesty's Tug or Troopship | |
| United Kingdom | Government research ships | RRS | Royal Research Ship | |
| United States | U.S. Army | USAV | United States Army Vessel | |
| United States (obsolete) | U.S. Navy | USF | United States Frigate | |
| United States (obsolete) | U.S. Navy | USFS | United States Flagship | |
| United States | U.S. Navy | USS | United States Ship | |
| United States | U.S. Navy Military Sealift Command | USNS | United States Naval Ship | |
| United States | U.S. Coast Guard | USCGC | United States Coast Guard Cutter | |
| Uruguay | Uruguay Navy | ROU | Republica del Oriental Uruguay | |
| Venezuela | Venezuelan Navy | ARV | Armada Republica Venezolana |
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 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.
In the United States Navy, all prefixes other than "USS," "USNS" and "USCGC" were obsoleted in 1901 when President Theodore Roosevelt signed into law a bill fixing American naval nomenclature.
A United States ship that has not yet been commissioned in the Navy does not hold the title of USS, it holds the title of PCU (Pre-commissioned unit) For example, say a shipyard is building a new aircraft carrier:—the Neversail. From the date the keel is laid to the date it is commissioned, it is called the PCU Neversail. Only after it enters active service in the fleet and is commissioned will it be referred to as the USS Neversail. In Australia, the prefix NUSHIP is used to denote ships that have yet to be commissioned into the fleet.
Note that while calling a US ship "the USS Neversail" may make grammatical sense, the preliminary article "the" is deprecated by nearly all style guides. Its British equivalent ("HMS Neversail," without the "the") is also deprecated, since "the Her Majesty's Ship" would be grammatically incorrect.
See also the WikiProject Ships.