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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,^[1] 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.^{[citation needed]}

Historically, prefixes for civilian vessels often identified the vessel's mode of propulsion, such as "MV" (motor vessel), "SS" (screw steamer;^[2] often cited as "steam ship"), or "PS" (paddle steamer).^[3][2]

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.^{[citation needed]}

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.^[4][5] 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.^[5][6]

However, not all navies used prefixes; this includes the significant navies of China, France and Russia.^{[citation needed]}

From the 20th century onwards, most navies identify ships by letters or hull numbers (pennant numbers)^[7] 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.^{[citation needed]}

These tables list both current and historical prefixes known to have been used.^[8]

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These prefixes are generally used for merchant vessels of any nationality.^[9]

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Country	Service	Prefix	Meaning
Albania	Albanian Naval Force	ALS	Albanian Ship (NATO prefix)
Algeria	Algerian National Navy	ANS	Algerian Navy Ship
Argentina	Argentine Navy	ARA	Navy of the Argentine Republic (Spanish: Armada de la República Argentina)
	Argentine Coast Guard	GC	Argentine Coast Guard Ship (Spanish: Guardacostas)
Australia	Royal Australian Navy	HMAS	His Majesty's Australian Ship/Submarine/Station
		NUSHIP	New Ship/Submarine (Yet to be commissioned)
		ADV	Australian Defence Vessel (non-commissioned naval-operated ships)
		MSA	Minesweeper Auxiliary[18]
	Australian Customs and Border Protection Service	ACV	Australian Customs Vessel
	Australian Border Force	ABFC	Australian Border Force Cutter
Australia (pre-Federation)	Colonial navies of Australia	HMCS	His Majesty's Colonial Ship
		HMQS	His Majesty's Queensland Ship (Queensland Maritime Defence Force)
		HMVS	His Majesty's Victorian Ship (Victorian Naval Forces)
Austria-Hungary	Austro-Hungarian Navy	SMS	Seiner Majestät Schiff (His Majesty's Ship)
Azerbaijan	Azerbaijani Navy	ARG	Azərbaycan Respublikasının hərbi Gəmisi (Warship of the Republic of Azerbaijan)
Bahamas	Royal Bahamas Defence Force	HMBS	His Majesty's Bahamian Ship
Bahrain	Royal Bahrain Naval Force	RBNS	Royal Bahrain Naval Ship
Bangladesh	Bangladesh Coast Guard	CGS	Coast Guard Ship
	Bangladesh Navy	BNS	Bangladesh Navy Ship
Barbados	Barbados Coast Guard	BCGS	Barbados Coast Guard Ship
Belgium	Belgian Navy	BNS	Belgian Naval Ship (NATO prefix)
Brazil	Brazilian Navy	(No Official Prefix)	Brazilian naval prefix indicates ship type.
British Raj	Royal Indian Marine (1892–1934)	RIMS	Royal Indian Marine Ship
	Royal Indian Navy (1934–1950)	HMIS	His Majesty's Indian Ship
Brunei	Royal Brunei Navy	KDB	Kapal Di-Raja Brunei (Royal Brunei Ship)
Bulgaria	Bulgarian Navy	BNG	NATO Designation
Canada	Royal Canadian Navy (formerly Canadian Forces Maritime Command)	HMCS NCSM	His Majesty's Canadian Ship (French: Navire canadien de Sa Majesté)
		CFAV NAFC	Canadian Forces Auxiliary Vessel (French: Navire auxiliaire des Forces canadiennes)
	Canadian Coast Guard	CCGS NGCC	Canadian Coast Guard Ship (French: Navire de Garde côtière canadienne)
		CCGC CGCC	Canadian Coast Guard Cutter (French: Cotre de Garde côtière canadienne) (no longer used)
	Department of Fisheries and Oceans, Department of Transport, and predecessor departments	CGS	Canadian Government Ship (no longer used)
		CSS	Canadian Survey Ship (no longer used)
		DGS	Dominion Government Ship (no longer used)
	Royal Canadian Sea Cadets	SCTV NECM	Sea Cadet Training Vessel (French: Navire école des cadets de la Marine)
People's Republic of China	People's Liberation Army Navy	(No Official Prefix)
Colombia	Armada Nacional	ARC	Armada de la República de Colombia (Navy of the Republic of Colombia)
Confederate States	Confederate States Navy	CSS	Confederate States Ship
Cook Islands	Cook Islands Police	CIPPB	Cook Islands Police Patrol Boat
Denmark	Royal Danish Navy	HDMS (Danish: KDM)	His/Her Danish Majesty's Ship (Danish: Kongelige Danske Marine)
		HDMY (Danish: KDM)	His/Her Danish Majesty's Yacht, crewed by Royal Danish Navy
Ecuador	Armada Ecuatoriana	BAE	Buque de la Armada de Ecuador (Ecuadorian Navy Ship)
Estonia	Estonian Navy	ENS (Estonian: EML)	Estonian Naval Ship (NATO designation)
	Estonian Coast Guard	ECGS	Estonian Coast Guard Ship (NATO designation)
Fiji	Republic of Fiji Navy	RFNS	Republic of Fiji Naval Ship
Finland	Finnish Navy	FNS	Finnish Navy Ship; Prefixes are for international identification only and never used internally.
France	French Navy	FS	French Ship (NATO designation); Prefixes are for international identification only and never used internally.
German Empire	Kaiserliche Marine	SMS	Seiner Majestät Schiff (His Majesty's Ship)
		SMU	Seiner Majestät Unterseeboot (His Majesty's Submarine)
Nazi Germany	Kriegsmarine	KMS / DKM (No Official Prefix)	Kriegsmarine Schiffe/Deutsche Kriegsmarine (Navy Ship/German Navy)
West Germany	Bundesmarine	FGS	Federal German Ship (NATO designation); Only used for international identification and never used internally.[19]
East Germany	Volksmarine
Germany	German Navy	FGS	Federal German Ship (NATO designation); Only used for international identification and never used internally.[19]
Kingdom of Greece	Royal Hellenic Navy	VP (Greek: ΒΠ)	"Royal Ship" (Greek: Βασιλικόν Πλοίον, romanized: Vassilikón Ploíon); Some English Language authors uses RHNS for Royal Hellenic Navy Ship or HHMS for His Hellenic Majesty's Ship.
Greece	Hellenic Navy	HS	Hellenic Ship (NATO designation); Only used for international identification, as prefix indicates ship type internally.
Guyana	Guyanese Coast Guard[20]	GDFS	Guyanese Defence Forces Ship
Kingdom of Hawaii	Hawaiian Navy	HHMS	His Hawaiian Majesty's Ship; the only one being Kaimiloa
Iceland	Icelandic Coast Guard	ICGV (Icelandic: VS)	Icelandic Coast Guard Vessel, (Icelandic:Varðskip)
India	Indian Coast Guard	ICGS	Indian Coast Guard Ship
	Indian Navy	INS	Indian Naval Ship
Indonesia	Indonesian Navy	RI	Republik Indonesia (Republic of Indonesia). Obsolete prefix used until 1960s.[21]
		KRI	Kapal Republik Indonesia (Ship of the Republic of Indonesia)
		KAL	Kapal Angkatan Laut (Navy Ship). For small boats which length is less than 36 m.
	Indonesian Army	ADRI	Angkatan Darat Republik Indonesia (Indonesian Army)
		AD	Angkatan Darat (Army). For combat boats.
	Indonesian Sea and Coast Guard Unit	KN	Kapal Negara (State Ship)
	Indonesian Maritime Security Agency
	Indonesian Water and Aviation Police Corps	KP	Kapal Polisi (Police Ship)
	Directorate General of Marine and Fisheries Resources Surveillance	KP	Kapal Pengawas (Overseer Ship)
	National Search and Rescue Agency	KN SAR	Kapal Negara (State Ship) Search and Rescue
	Directorate General of Customs and Excise	BC	Bea Cukai (Customs–Excise)
	Directorate of Sea Traffic	KM	Kapal Motor (Motor Vessel)
Imperial Iran	Imperial Iranian Navy	IIS[22]	Imperial Iranian Ship (Persian: ناو شاهنشاهی ایران)
Iran	Islamic Republic of Iran Navy	IRIS[23]	Islamic Republic of Iran ship (Persian: ناو جمهوری اسلامی ایران)
Ireland	Irish Naval Service	LÉ	Long Éireannach (Irish ship)
	Commissioners of Irish Lights	ILV	Irish Lights Vessel (Lighthouse tender)
Israel	Israeli Sea Corps	INS	Israeli Naval Ship (Internally Hebrew acronym אח"י (A.Ch.Y.) is used standing for אניית חיל הים (Oniyat Heyl HaYam – Sea Corps Ship)
Kingdom of Italy	Regia Marina	RN	Regia Nave – Royal Ship
		R.Smg.	Regio Sommergibile – Royal Submarine
Italy	Marina Militare	ITS	Italian Ship (NATO designation); Italy no longer uses prefixes
Jamaica	Jamaica Defence Force	HMJS	His Majesty's Jamaican Ship
Empire of Japan	Imperial Japanese Navy	HIJMS (obsolete)	His Imperial Japanese Majesty Ship (Used externally, between the Meiji Era and the Washington Naval Treaty. Though abandoned later on, Japanese vessels were still referred as such during World War II.
Japan	Japan Maritime Self-Defense Force	JDS or JS	Japanese Defense Ship or Japanese Ship
Kenya	Kenyan Navy	KNS	Kenyan Naval Ship
Kiribati	Kiribati Police Force	RKS	Republic of Kiribati Ship
North Korea	Korean People's Navy	(No Official Prefix)	Does not use any prefixes at all, either for international identification or for ship type indication.
Kuwait	Kuwait Naval Force	KNS	Kuwait Navy Ship
Korean Empire	Imperial Korean Navy	KIS	Korean Imperial Ship
South Korea	Republic of Korea Navy	ROKS	Republic of Korea Ship
Latvia	Latvian Navy	LVNS	Latvian Naval Ship (NATO designation)
Lithuania	Lithuanian Navy	LKL	Lietuvos Karinis Laivas (Lithuanian Military Ship)
		LNS	Lithuanian Ship (NATO designation)
Malaysia	Royal Malaysian Navy	KD	Kapal Di-Raja – His Majesty's Ship, literal: Royal Ship.
		KLD	Kapal Layar Di-Raja - His Majesty's Sailing Ship, literal: Royal Sailing Ship. (Used by KLD Tunas Samudera)
	Malaysian Maritime Enforcement Agency	KM	Kapal Maritim – Maritime Ship
Marshall Islands	Marshall Islands Police	RMIS	Republic of the Marshall Islands Ship
Federated States of Micronesia	FSM National Police	FSM	Federated States of Micronesia
Mexico	Armada de México	ARM	Armada de la República Mexicana
Myanmar	Myanmar Navy	UMS	Union of Myanmar Ship (Burmese: Myanmar Sit Yay Yin)
Namibia	Namibian Navy	NS	Namibian Ship
Netherlands	Royal Netherlands Navy	HNLMS (Dutch: Zr.Ms./Hr.Ms.)	His/Her Netherlands Majesty's Ship (Dutch: Zijner/Harer Majesteits)
New Zealand	Royal New Zealand Navy	HMNZS	His Majesty's New Zealand Ship
Nigeria	Nigerian Navy	NNS	Nigerian Naval Ship
Norway	Royal Norwegian Navy	HNoMS (Norwegian: KNM)	His Norwegian Majesty's Ship (Norwegian: Kongelige Norske Marine), in use since 1946.
		HNoMY (Norwegian: KS)	His Norwegian Majesty's Yacht (Norwegian: Kongenskipet). The only vessel with the prefix, HNoMY Norge, is owned by the King but crewed by his Navy since 1948.
	King of Norway	KSJ	King's Sloop Norwegian: Kongesjaluppen Used on two small motorised pleasure vessels named Stjernen & Stjernen (II) owned by the King from 1899-1940 and 1945-present.
	Norwegian Coast Guard	NoCGV (Norwegian: KV)	Norwegian Coast Guard Vessel (Norwegian: Kystvakten)
Oman	Royal Navy of Oman	SNV	Sultanate Naval Vessel
Pakistan	Pakistan Navy	PNS	Pakistan Naval Ship
	Pakistan Maritime Security Agency	PMSS	Pakistan Maritime Security Ship
Palau	Palau Police	PSS	Palau State Ship
Papua New Guinea	Papua New Guinea Defence Force	HMPNGS	His/Her Majesty's Papua New Guinea Ship
Paraguay	Paraguayan Navy	ARP	Armada de la República del Paraguay (Navy of the Republic of Paraguay)
Peru	Peruvian Navy	BAP	Peruvian Navy Ship (Spanish: Buque Armada Peruana), Since 1921
		BIC	Scientific Research Ship (Spanish: Buque de Investigación Científica)
Philippines	Philippine Navy, Philippine Coast Guard, Bureau of Fisheries and Aquatic Resources	BRP	Barko ng Republika ng Pilipinas; in use since 1 July 1980 (Ship of the Republic of the Philippines)
		RPS	Republic of the Philippines Ship (Obsolete); before 1 July 1980
Poland	Polish Navy	ORP	Okręt Rzeczypospolitej Polskiej (Warship of the Republic of Poland)
Portugal	Marinha Portuguesa	NRP	Navio da República Portuguesa (Ship of the Portuguese Republic)
		PNS	Portuguese Navy Ship (NATO designation); Never used internally.
		UAM	Unidade Auxiliar da Marinha – Navy Auxiliary Unit (used by non-military ships of Portuguese Navy)
Prussia	Prussian Navy	SMS	Seiner Majestät Schiff (His Majesty's Ship)
Kingdom of Romania	Royal Romanian Navy	NMS	Nava Majestăţii Sale (His/Her Majesty's Ship)
Romania	Romanian Navy	ROS	Romanian Ship (NATO designation); Prefixes are for international identification only and never used internally.
		SMR	Serviciul Maritim Român (Romanian Maritime Service); used by transport ships
Russian Empire	Imperial Russian Navy	(No Official Prefix)	Some authors use "HIRMS" for "His Imperial Russian Majesty's Ship" to identify them.
Russia	Russian Navy	RFS	Russian Federation Ship (NATO designation; Prefixes are for international identification only and never used internally.
Saudi Arabia	Saudi Navy	HMS	His Majesty's Ship (Same as the Royal Navy)
Singapore	Republic of Singapore Navy	RSS	Republic of Singapore Ship
Slovenia	Slovenian Navy	SNS	Slovenian Naval Ship (NATO prefix)
Solomon Islands	Royal Solomon Islands Police	RSIPV	Royal Solomon Islands Police Vessel
South Africa	South African Navy	SAS	South African Ship/Suid-Afrikaanse Skip (previously HMSAS – His/Her Majesty's South African Ship)
		SATS	South African Training Ship
Soviet Union	Soviet Navy	(No Official Prefix)	Some authors use "USSRS" for "Union of Soviet Socialist Republics Ship" (Russian: Корабль Союза Советских Социалистических Республик).[24]
Spain	Armada Española	ESPS Buque de la A	Spanish Navy Ship (Spain does not use prefixes internally. ESPN or SPS are no longer used)
Sri Lanka	Sri Lankan Navy	SLNS	Sri Lanka Naval Ship
	Sri Lanka Coast Guard	SLCG	Sri Lanka Coast Guard
Sweden	Swedish Navy	HMS (English: HSwMS)	Hans/Hennes Majestäts Skepp (His/Her Majesty's Ship) HSwMS (His/Her Swedish Majesty's Ship) is used in English to avoid confusion with Royal Navy ships
	Swedish Coast Guard	KBV	Swedish Coast Guard Vessel (Swedish: Kustbevakningen)
Republic of China (Taiwan)	Republic of China Navy	ROCS	Republic of China Ship; CNS for "Chinese Navy Ship" was used before 1949
Thailand	Royal Thai Navy	HTMS	His Thai Majesty's Ship
Timor-Leste	Timor Leste Defense Force	NRTL	Navio da República de Timor Leste (Ship of the Timor Leste Republic)
Tonga	Tonga Defence Services	VOEA	Vaka O Ene Afio (His Majesty's Vessel)
Turkey	Turkish Navy	TCG	Ship of the Turkish Republic (Turkish: Türkiye Cumhuriyeti Gemisi.)
Tuvalu	Tuvalu Police Force	HMTSS	His/Her Majesty's Tuvalu Surveillance Ship[25][26]
Trinidad and Tobago	Trinidad and Tobago Defence Force	TTS	Trinidad and Tobago Ship
United Kingdom	Ships carrying mail	RMS	Royal Mail Steamer/Ship
	Cable ship	HMTV	His Majesty's Telegraph Vessel
	Motor Ship	MS	Motor Ship. Cruise ships such as the MS Queen Elizabeth, which do not carry post
	Fishery protection vessels	FPV	Fisheries Protection Vessel
	Royal Air Force	HMAFV	His Majesty's Air Force Vessel (not currently in use)
	Royal Fleet Auxiliary ships	RFA	Royal Fleet Auxiliary
	Royal Maritime Auxiliary Service ships	RMAS	Royal Maritime Auxiliary Ship (now obsolete)
	Royal Naval Auxiliary Service	XSV	Auxiliary Service Vessel (now obsolete)
	Royal Navy	HM Sloop	His Majesty's Sloop (now obsolete)
		HMS	His Majesty's Ship/Submarine
		HMSm	His Majesty's Submarine (not currently in use)
		HMT	Hired Military Transport[27][13] (not currently in use) His Majesty's Transport/Troopship/Trawler/Tug[28]
		HMAV	His Majesty's Armed Vessel[29] (not currently in use)
		HMY	His Majesty's Yacht (not currently in use)
		HMMGB	His Majesty's Motor Gun Boat (not currently in use)
		HMM	His Majesty's Monitor (not currently in use)
		HMSML	His Majesty's Survey Motor Launch
		HBMS	His Britannic Majesty's Ship (archaic)
		HM	His Majesty's, then used with the type of ship in military use (e.g. "HM Trawler" or "HM Rescue Tug")
	Hospital Ships	HMHS	His Majesty's Hospital Ship
	Joint Services Sail Training Yachts (JSASTC)	HMSTC	His/Her Majesty's Sail Training Craft
	Trinity House	THV	Trinity House Vessel (Lighthouse and Buoy Tender)
	Northern Lighthouse Board	NLV	Northern Lighthouse Vessel (Lighthouse tender)
	Commissioners of Irish Lights	ILV	Irish Lights Vessel (Lighthouse tender)
	British Army	HMAV	His/Her Majesty's Army Vessel[30]
		RCLV	Royal Corps of Logistics Vessel (not currently in use)
	Government research ships	RRS	Royal Research Ship
	HM Revenue and Customs/Border Force	HMCC, HMC	His Majesty's Customs Cutter shortened to His Majesty's Cutter after being transferred to Border Force
	HM Customs and Excise (replaced by HMRC, above)	HMRC	His Majesty's Revenue Cutter (not used since 18 April 2005). Also His Majesty's Revenue Cruiser (as per HMRC Vigilant 1947. Not used since ca. 1960)
United States	United States Air Force	USAF, USAFS	United States Air Force ship (not currently in use)
	United States Army (modern)	USAS	United States Army Ship (modern)
		USAV	United States Army Vessel (modern)
	United States Army (historical)
		USAT	United States Army Transport (large Army owned bareboat chartered troop or cargo transports, not in use after 1950)
		USACT	United States Army Chartered Transport (usage WW I only for time or voyage chartered ships; eg: Artemis 1917—1919)
		USAMP	U.S. Army Mine Planter (not currently in use)
		USAJMP	U.S. Army Junior Mine Planter (not currently in use)
		U.S. Army	Vessels not otherwise designated: tugs, FS, Q, P etc. (not currently in use)
		USAHS	United States Army Hospital Ship (not currently in use)
	United States Navy	USF	United States Frigate (obsolete)
		USFS	United States Flagship (obsolete)
		USS	United States Ship – Commissioned warships only.[5]
		USNV	United States Naval Vessel (Small utility vessels, not MSC, operated by local commands)[31]
	U.S. Navy Military Sealift Command (MSC)	USNS	United States Naval Ship (USN-owned, civilian crews)
	United States Coast Guard	USCGC	United States Coast Guard Cutter
		USCGD	United States Coast Guard Destroyer (not currently in use)
	National Oceanic and Atmospheric Administration	NOAAS	National Oceanic and Atmospheric Administration Ship
	United States Coast and Geodetic Survey	USC&GS	United States Coast and Geodetic Survey (obsolete); occasionally a second "S" for "survey ship" was used
	United States Environmental Protection Agency	US EPA	United States Environmental Protection Agency; no "S" for "ship" is used
	United States Commission of Fish and Fisheries	USFC	United States Fish Commission (obsolete); commonly used informal name for the Commission; no "S" for "ship" was used
	United States Bureau of Fisheries	USFS	United States Fisheries Service (obsolete); alternative informal name for the Bureau; no "S" for "ship" was used
	United States Fish and Wildlife Service	US FWS	United States Fish and Wildlife Service; no "S" for "ship" used
	United States Lighthouse Service	USLHT	United States Lighthouse Tender (obsolete)
	United States Public Health Service	USPHS	United States Public Health Service; no "S" for "ship" used
	United States Revenue-Marine (1790–1894) and United States Revenue Cutter Service (1894-1915)	USRC	United States Revenue Cutter (obsolete)
Uruguay	Uruguayan Navy	ROU	República Oriental del Uruguay
Vanuatu	Vanuatu Police Force	RVS	Republic of Vanuatu Ship
Venezuela	Venezuelan Navy	FNV	Fuerzas Navales de Venezuela Not in use since 1949
		ARV	Armada República de Venezuela Not in use 1999
		ARBV	Armada República Bolivariana de Venezuela
Vietnam	Vietnam People's Navy	VPNS	Vietnam People's Navy Ship. The Vietnam People's Navy does not internally and formally use this designation despite its unofficial but frequent usage by foreign media at international events. Since a major portion of the Vietnamese fleet is not named literally and only has standardized non-prefixed hull numbers, the VPNS prefix is sometimes used with the ship's hull number (for example, VPNS 20)[32] to make it look cosmetically more synchronous and consistent with other navies' prefixed ship names in international activities.
South Vietnam	Republic of Vietnam Navy	RVNS	Republic of Vietnam Navy Ship or Republic of Viet-Nam Ship (obsolete)
Kingdom of Yugoslavia	Royal Yugoslav Navy	KB	Serbian: Краљевски брод, romanized: Kraljevski brod (English: Royal Ship)
Socialist Federal Republic of Yugoslavia  Federal Republic of Yugoslavia  Serbia and Montenegro	Jugoslovenska Ratna Mornarica JRM (English: Yugoslavia war navy) Yugoslav Navy 1969–1992 Ratna Mornarica Vojske Jugoslavije RМVЈ (English: War navy of Yugoslavia Armed Forces) 1992–2003	RTOP	Raketna Topovnjača or Ракетна Топовњача (English: Rocket gunship), named by Yugoslavia peoples heroes
		RČ	Raketni Čamac or Ракетни Чамац (English: Rocket boat), 1969–1992, named by Yugoslavia peoples heroes
		VPBR	Veliki Patrolni Brod or Велики Патролни Брод (English: Big patrol ship), 1969–1992, named by Yugoslavia coastal towns
		TČ	Torpedni Čamac or Торпедни Чамац (English: Torpedo boat), 1969–1992
		PČ	Patrolni Čamac or Патролни Чамац (English: Patrol boat), 1969–1992, named by mountains
		PO	Pomoćni Oružar or Помоћни Оружар (English: Auxiliary аrmourer), 1969–1992
		RML	Rečni minolovac or Речни миноловац (English: River minesweepers), 1969–1992, named by places of WWII battles
		RPB	Rečni patrolni brod or Речни патролни брод (English: River patrol boat), 1969–1992
		P	Podmornica or Подморница (English: Submarine), 1969–1992, named by rivers or human qualities
		RЕ	Razarač Eskortni or Разарач Ескортни (English: Escort destroyer), 1969–1992
		PT	Pomoćni transportni or Помоћни транспортни (English: Auxiliary transport), 1969–1992
		DČ	Desantni čamci or Десантни чамци (English: Landing craft), 1969–1992

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.^[33] 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.^[34]

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.^[5] 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.^[35] 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.^[5] 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.^[5] 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.^{[36] [5]} Military Sealift Command (MSC) civilian crewed ships "in service" are given the prefix United States Naval Ship (USNS).^[5]

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.

• Star Trek – the United Federation of Planets uses the prefix "USS" for its starships. Dialogue in earlier episodes of the series indicated that it referred to "United Space Ship".^[37] In the alternate "Mirror Universe", the Terran Empire use an "ISS" prefix instead. Other races use different prefixes for their ships:
  • Klingons use IKS (Imperial Klingon Ship) or IKC (Imperial Klingon Cruiser).
  • Romulan vessels typically receive the prefix IRW (Imperial Romulan Warbird), or RIS where some speculate that it means "Romulan Imperial Ship", and ChR. (ChR is from novelist Diane Duane's imagining of the Star Trek Universe, in which the Romulans refer to their home planet as "Ch'Rihan". Though Duane's version has a loyal following among many fans, it is not considered official Star Trek canon; similarly, the Ferengi designation of FMS, and the Cardassian CDS, are also not canon.)
• Star Wars – The Galactic Empire sometimes uses the prefix ISD for Imperial Star Destroyer.
• Babylon 5 – The Earth Alliance uses the prefix "EAS" for "Earth Alliance Ship". Some fan material also uses it for "Earth Alliance Station".
• Elite: Dangerous – The Federation uses the prefix "FNS" (Federal Naval Ship) for some military ships. The Empire uses "INV" (Imperial Naval Vessel). The alliance uses "ADF" (Alliance Defense Force).
• Firefly – Vessels in the Union of Allied Planets fleet are given the prefix "IAV", for Interstellar Alliance Vessel.
• Wing Commander – The Terran Confederation uses TCS (Terran Confederation Ship) for its vessels.
• Halo – United Nations Space Command spacecraft use the prefix "UNSC". The Covenant use three letter designations for ship class such as CAS or CSO
• Mass Effect – features several prefixes, primarily "SSV" for "Systems Alliance space vehicle"^[38] and "MSV" for "Merchant Space Vehicle", used on numerous human commercial ships, as well as "PFS" for a Turian Hierarchy naval craft, and a freighter AML Demeter of unknown affiliation.
• Dead Space – "USG", standing for "United Spacefaring Guild", which oversees civilian spacecraft operation, including the planet-cracker class leader USG Ishimura of the Concordance Extraction Corporation; "USM" for the Earth Defense Force of EarthGov; and "CMS" for its predecessor, the Sovereign Colonies Armed Forces.
• StarCraft: Brood War – The United Earth Directorate uses DSS (presumably for Directorate Space Ship, e. g. DSS Aleksander); the Terran Confederacy used CSF (Confederate Space Fleet, e. g. CSF Ragnorak) for their battlecruisers.
• Killzone – The Interplanetary Strategic Alliance (ISA) uses "ISC", for Interplanetary Strategic Cruiser.
• The Moon is a Harsh Mistress – The Federated Nations use "FNS", presumably meaning "Federated Nations Ship".
• Alien – The ships use prefix "USCSS" for "United States Cargo SpaceShip" on the Nostromo, Prometheus, and Covenant.
• The Lost Fleet – The Alliance use the prefix "ASN" for "Allied Systems Navy" (or possibly "Alliance of Systems Navy"), the Syndicate Worlds do not use prefixes.
• CoDominium – CoDominium vessels use the prefix "CDS" for CoDominium Ship.
• "Honorverse" – The Manticoran kingdom uses "HMS" as a prefix, the Graysons use "GNS"(Grayson Navy Ship), and the Havenite ships use "PNS" (People's Navy Ship) and later "RHNS" (Republic of Haven Navy Ship), being reflections of actual ship prefixing traditions, and mirroring the Napoleonic wars. The Solarian League uses "SLNS" (Solarian League Navy Ship) and the Andermani Empire uses "IANS" for Imperial Andermani Navy Ship.
• The Culture – Ships are identified by a three-letter prefix denoting class (such as GSV for "General Systems Vehicle" or ROU for "Rapid Offensive Unit"), followed by their personal name.
• The Expanse – Ships of the United Nations Navy use the prefix "UNN," while ships of the Martian Congressional Republic Navy are prefixed with "MCRN". The Nauvoo, a generation ship commissioned by the Church of Latter Day Saints was prefixed with "LDSS" for "Latter Day Saints' Ship", and later changed to "OPAS" and re-christened as the "OPAS Behemoth" representing the Outer Planets Alliance.
• Unreal Tournament – Ships mentioned there have prefixes such as ITV ("Interstellar Transport Vessel", the first non-tutorial match in the tournament happens on board of ITV Oblivion) and ISV ("Interstellar Science Vessel", ship's name being ISV-Kran from Unreal).
• Unreal: Return to Na Pali – ISV (ISV-Kran) and UMS ("Unified Military Services", a prefix for warships).
• The Orville—The Planetary Union uses the prefix "USS", presumably for "Union Space Ship" (in homage to Star Trek).
• Treasure Planet: Battle at Procyon - The Terran Empire uses the prefix RLS, which stands for Royal Light Ship; this is also a direct homage to Robert Louis Stevenson, author of the original Treasure Island. The Procyon Expanse uses the prefix PSR, which stands for Procyon Star Runner.
• Destroyermen - the Grand Alliance uses the "USS" prefix, since all Allied warships are run by the Americaan (sic) Clan. The Alliance's only airship is given the prefix "UHAS" (United Homes Air Ship). The Empire of New Britain Isles uses "HIMS" (His/Her Imperial Majesty's Ship). The Republic of Real People uses "RRPS" (Republic of Real People Ship). The New United States uses "NUSS" (New United States Ship). Neither the Holy Dominion nor the League of Tripoli use prefixes, although the KMS Hessen is mentioned once, it is not clear if the prefix is internally used or not.
• Titanfall - The Interstellar Manufacturing Corporation, the main antagonists of the series, use the "IMS" prefix. The origin of this prefix is unknown.
• FreeSpace - Various ship prefixes are used depending on the species, faction allegiance, and class of the vehicle. Prominent examples include: "GT" and "GV" for "Galactic Terran" and "Galactic Vasudan" respectively, "NT" for "Neo-Terran," "PV" for "Parliamentary Vasudan," and just "S" for "Shivan." These are then further supplemented with a type of ship identifier following the species and faction prefixes, such as "B" for "Bomber," "C" for "Cruiser," "Cv" for "Corvette," "D" for "Destroyer," and "F" for "Fighter," among many examples. As such, "PVD" would indicate a "Parliamentary Vasudan Destroyer," "NTF" would indicate a "Neo-Terran Fighter," "GTC" would indicate a "Galactic Terran Cruiser", "GVCv" would indicate a "Galactic Vasudan Corvette," and "SB" would indicate a "Shivan Bomber."
• "Helldivers 2" - "SES" is used for "Super Earth Ship"

Wikimedia Commons has media related to Ship prefixes.

• Warship National Prefixes