# 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.

## Usage

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.

## Generic (merchant navy) prefixes

These prefixes are generally used for merchant vessels of any nationality.
| Prefix | Meaning |
| AE | Ammunition ship |
| AFS | Combat stores ship |
| AHT | Anchor handling tug |
| AHTS | Anchor handling tug supply vessel |
| AO | United States Navy oiler |
| AOG | Gasoline tanker |
| AOR | Auxiliary replenishment oiler |
| AOT | Transport oiler |
| ASDS | Autonomous Spaceport Drone Ship |
| ATB | Articulated Tug Barge |
| CRV | Coastal Research Vessel |
| C/F | Car ferry |
| CS | Container ship or Cable ship |
| DB | Derrick barge |
| DEPV | Diesel Electric Paddle Vessel |
| DLB | Derrick Lay Barge |
| DCV | Deepwater Construction Vessel |
| DSV | Diving support vessel or deep-submergence vehicle |
| DV | Dead vessel |
| ERRV | Emergency Response Rescue Vessel |
| EV | Exploration Vessel |
| FPSO | Floating production storage and offloading vessel |
| FPV | Free Piston Vessel |
| FPV | Fishery Protection Vessel |
| FT | Factory Stern Trawler |
| FV | Fishing Vessel |
| GTS | Gas Turbine Ship |
| HLV | Heavy lift vessel |
| HMT | Hired military transport (not currently in use) |
| HMHS | His(/Her) Majesty's Hospital Ship |
| HSC | High Speed Craft |
| HSF | High Speed Ferry |
| HTV | Heavy transport vessel |
| IRV | International Research Vessel |
| ITB | Integrated Tug barge |
| LB | Liftboat |
| LNG/C | Liquefied natural gas carrier |
| LPG/C | Liquefied petroleum gas carrier |
| MF | Motor ferry |
| MFV | Motor fishing vessel (mainly UK Royal Naval Reserve) |
| MS (M/S) | Motor ship (interchangeable with MV) |
| MSV | Multipurpose support/supply vessel |
| MSY | Motor Sailing Yacht |
| MT | Motor Tanker |
| MTS | Marine towage and salvage/tugboat |
| MV (M/V) | Motor Vessel (interchangeable with MS) |
| MY (M/Y) | Motor Yacht |
| NB | Narrowboat |
| NRV | NATO Research Vessel |
| NS | Nuclear ship |
| OSV | Offshore supply vessel |
| PS | Paddle steamer |
| PSV | Platform supply vessel |
| QSMV | Quadruple screw motor vessel |
| QTEV | Quadruple turbo electric vessel |
| RMP | Royal Mail Packet |
| RMS | Royal Mail Ship or Royal Mail Steamer |
| RMV | Royal Mail Vessel |
| RNLB | Royal National Lifeboat |
| RNMB | Royal Navy Motor Boat |
| RRS | Royal Research Ship |
| RV / RSV | Research vessel/Research Survey Vessel |
| SB | Sailing Barge |
| SL | Steam Launch |
| SS (S/S) | Single-screw steamship (also used as generic term for any steam-powered ship) |
| SSCV | Semi-submersible crane vessel |
| SSS | Sea Scout Ship |
| SSV | Sailing School Vessel, or Submarine and Special Warfare Support Vessel |
| ST | Steam tug or Steam trawler |
| STS | Sail training ship |
| STV | Sail Training Vessel or Steam Turbine Vessel |
| SV (S/V) | Sailing Vessel |
| SY (S/Y) | sailing yacht or steam yacht |
| TB | Tug boat |
| TIV | Turbine Installation Vessel |
| TEV | Turbine electric vessel |
| TrSS | Triple-screw steamship or steamer |
| TS | Training Ship or turbine steamship or turbine steam ship |
| Tr.SMV | Triple-Screw Motor Vessel |
| TSMV | Twin-Screw Motor Vessel |
| TSMS | Twin-Screw Motor Ship |
| TSS | Twin-screw steamship or steamer |
| TST | Twin-screw tug |
| TT (T/T) | "Tender to" ..., the prefix is placed on the tender followed by the name of the mother ship; or Turbine Tanker |
| TV | Training vessel |
| ULCC | Ultra Large Crude Carrier |
| VLCC | Very Large Crude Carrier |
| YD | Yard derrick |
| YT | Yard Tug |
| YMT | Yard Motor Tug |
| YTB | Yard Tug Big |
| YTL | Yard Tug Little |
| YTM | Yard Tug Medium |
| YW | Water barge, self-propelled |
| YWN | Water barge, non-propelled |
| YOS | Concrete vessel |

## National or military prefixes

| 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) |
| Argentina | Argentine Coast Guard | GC | Argentine Coast Guard Ship (Spanish: Guardacostas) |
| Australia | Royal Australian Navy | HMAS | His Majesty's Australian Ship/Submarine/Station |
| Australia | Royal Australian Navy | NUSHIP | New Ship/Submarine (Yet to be commissioned) |
| Australia | Royal Australian Navy | ADV | Australian Defence Vessel (non-commissioned naval-operated ships) |
| Australia | Royal Australian Navy | MSA | Minesweeper Auxiliary |
| Australia | Australian Customs and Border Protection Service | ACV | Australian Customs Vessel |
| Australia | Australian Border Force | ABFC | Australian Border Force Cutter |
| Australia (pre-Federation) | Colonial navies of Australia | HMCS | His Majesty's Colonial Ship |
| Australia (pre-Federation) | Colonial navies of Australia | HMQS | His Majesty's Queensland Ship (Queensland Maritime Defence Force) |
| Australia (pre-Federation) | Colonial navies of Australia | 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 | 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 |
| British Raj | 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) |
| Canada | Royal Canadian Navy (formerly Canadian Forces Maritime Command) | CFAV NAFC | Canadian Forces Auxiliary Vessel (French: Navire auxiliaire des Forces canadiennes) |
| Canada | Canadian Coast Guard | CCGS NGCC | Canadian Coast Guard Ship (French: Navire de Garde côtière canadienne) |
| Canada | Canadian Coast Guard | CCGC CGCC | Canadian Coast Guard Cutter (French: Cotre de Garde côtière canadienne) (no longer used) |
| Canada | Department of Fisheries and Oceans, Department of Transport, and predecessor departments | CGS | Canadian Government Ship (no longer used) |
| Canada | Department of Fisheries and Oceans, Department of Transport, and predecessor departments | CSS | Canadian Survey Ship (no longer used) |
| Canada | Department of Fisheries and Oceans, Department of Transport, and predecessor departments | DGS | Dominion Government Ship (no longer used) |
| Canada | 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) |
| Denmark | Royal Danish Navy | 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) |
| Estonia | 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) |
| German Empire | Kaiserliche Marine | 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. |
| East Germany | Volksmarine | | |
| Germany | German Navy | FGS | Federal German Ship (NATO designation); Only used for international identification and never used internally. |
| 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 | 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 |
| India | Indian Navy | INS | Indian Naval Ship |
| Indonesia | Indonesian Navy | RI | Republik Indonesia (Republic of Indonesia). Obsolete prefix used until 1960s. |
| Indonesia | Indonesian Navy | KRI | Kapal Republik Indonesia (Ship of the Republic of Indonesia) |
| Indonesia | Indonesian Navy | KAL | Kapal Angkatan Laut (Navy Ship). For small boats which length is less than 36 m. |
| Indonesia | Indonesian Army | ADRI | Angkatan Darat Republik Indonesia (Indonesian Army) |
| Indonesia | Indonesian Army | AD | Angkatan Darat (Army). For combat boats. |
| Indonesia | Indonesian Sea and Coast Guard Unit | KN | Kapal Negara (State Ship) |
| Indonesia | Indonesian Maritime Security Agency | KN | Kapal Negara (State Ship) |
| Indonesia | Indonesian Water and Aviation Police Corps | KP | Kapal Polisi (Police Ship) |
| Indonesia | Directorate General of Marine and Fisheries Resources Surveillance | KP | Kapal Pengawas (Overseer Ship) |
| Indonesia | National Search and Rescue Agency | KN SAR | Kapal Negara (State Ship) Search and Rescue |
| Indonesia | Directorate General of Customs and Excise | BC | Bea Cukai (Customs–Excise) |
| Indonesia | Directorate of Sea Traffic | KM | Kapal Motor (Motor Vessel) |
| Imperial Iran | Imperial Iranian Navy | IIS | Imperial Iranian Ship (Persian: ناو شاهنشاهی ایران) |
| Iran | Islamic Republic of Iran Navy | IRIS | Islamic Republic of Iran ship (Persian: ناو جمهوری اسلامی ایران) |
| Ireland | Irish Naval Service | LÉ | Long Éireannach (Irish ship) |
| Ireland | 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 |
| Kingdom of Italy | Regia Marina | 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) / IJN (unofficial) | 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. The unofficial name IJN stands for "Imperial Japanese Navy" is frequently used in various sources and media. |
| 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) |
| Lithuania | Lithuanian Navy | LNS | Lithuanian Ship (NATO designation) |
| Malaysia | Royal Malaysian Navy | KD | Kapal Di-Raja – His Majesty's Ship, literal: Royal Ship. |
| Malaysia | Royal Malaysian Navy | KLD | Kapal Layar Di-Raja - His Majesty's Sailing Ship, literal: Royal Sailing Ship. (Used by KLD Tunas Samudera) |
| Malaysia | 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. |
| Norway | Royal Norwegian Navy | 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. |
| Norway | 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. |
| Norway | 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 | 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 |
| Peru | Peruvian Navy | 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) |
| Philippines | Philippine Navy, Philippine Coast Guard, Bureau of Fisheries and Aquatic Resources | 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) |
| Portugal | Marinha Portuguesa | PNS | Portuguese Navy Ship (NATO designation); Never used internally. |
| Portugal | Marinha Portuguesa | 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. |
| Romania | Romanian Navy | 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) |
| South Africa | South African Navy | 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). |
| 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 | 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 |
| Sweden | 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 |
| Trinidad and Tobago | Trinidad and Tobago Defence Force | TTS | Trinidad and Tobago Ship |
| United Kingdom | Ships carrying mail | RMS | Royal Mail Steamer/Ship |
| United Kingdom | Cable ship | HMTV | His Majesty's Telegraph Vessel |
| United Kingdom | Motor Ship | MS | Motor Ship. Cruise ships such as the MS Queen Elizabeth, which do not carry post |
| United Kingdom | Fishery protection vessels | FPV | Fisheries Protection Vessel |
| United Kingdom | Royal Air Force | HMAFV | His Majesty's Air Force Vessel (not currently in use) |
| United Kingdom | Royal Fleet Auxiliary ships | RFA | Royal Fleet Auxiliary |
| United Kingdom | Royal Maritime Auxiliary Service ships | RMAS | Royal Maritime Auxiliary Ship (now obsolete) |
| United Kingdom | Royal Naval Auxiliary Service | XSV | Auxiliary Service Vessel (now obsolete) |
| United Kingdom | Royal Navy | HM Sloop | His Majesty's Sloop (now obsolete) |
| United Kingdom | Royal Navy | HMS | His Majesty's Ship/Submarine |
| United Kingdom | Royal Navy | HMSm | His Majesty's Submarine (not currently in use) |
| United Kingdom | Royal Navy | HMT | Hired Military Transport (not currently in use) His Majesty's Transport/Troopship/Trawler/Tug |
| United Kingdom | Royal Navy | HMAV | His Majesty's Armed Vessel (not currently in use) |
| United Kingdom | Royal Navy | HMY | His Majesty's Yacht (not currently in use) |
| United Kingdom | Royal Navy | HMMGB | His Majesty's Motor Gun Boat (not currently in use) |
| United Kingdom | Royal Navy | HMM | His Majesty's Monitor (not currently in use) |
| United Kingdom | Royal Navy | HMSML | His Majesty's Survey Motor Launch |
| United Kingdom | Royal Navy | HBMS | His Britannic Majesty's Ship (archaic) |
| United Kingdom | Royal Navy | HM | His Majesty's, then used with the type of ship in military use (e.g. "HM Trawler" or "HM Rescue Tug") |
| United Kingdom | Hospital Ships | HMHS | His Majesty's Hospital Ship |
| United Kingdom | Joint Services Sail Training Yachts (JSASTC) | HMSTC | His/Her Majesty's Sail Training Craft |
| United Kingdom | Trinity House | THV | Trinity House Vessel (Lighthouse and Buoy Tender) |
| United Kingdom | Northern Lighthouse Board | NLV | Northern Lighthouse Vessel (Lighthouse tender) |
| United Kingdom | Commissioners of Irish Lights | ILV | Irish Lights Vessel (Lighthouse tender) |
| United Kingdom | British Army | HMAV | His/Her Majesty's Army Vessel |
| United Kingdom | British Army | RCLV | Royal Corps of Logistics Vessel (not currently in use) |
| United Kingdom | Government research ships | RRS | Royal Research Ship |
| United Kingdom | 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 |
| United Kingdom | 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 | United States Army (modern) | USAS | United States Army Ship (modern) |
| United States | United States Army (modern) | USAV | United States Army Vessel (modern) |
| United States | United States Army (historical) |
| United States | United States Army (historical) | USAT | United States Army Transport (large Army owned bareboat chartered troop or cargo transports, not in use after 1950) |
| United States | United States Army (historical) | USACT | United States Army Chartered Transport (usage WW I only for time or voyage chartered ships; eg: Artemis 1917—1919) |
| United States | United States Army (historical) | USAMP | U.S. Army Mine Planter (not currently in use) |
| United States | United States Army (historical) | USAJMP | U.S. Army Junior Mine Planter (not currently in use) |
| United States | United States Army (historical) | U.S. Army | Vessels not otherwise designated: tugs, FS, Q, P etc. (not currently in use) |
| United States | United States Army (historical) | USAHS | United States Army Hospital Ship (not currently in use) |
| United States | United States Navy | USF | United States Frigate (obsolete) |
| United States | United States Navy | USFS | United States Flagship (obsolete) |
| United States | United States Navy | USS | United States Ship – Commissioned warships only. |
| United States | United States Navy | USNV | United States Naval Vessel (Small utility vessels, not MSC, operated by local commands) |
| United States | U.S. Navy Military Sealift Command (MSC) | USNS | United States Naval Ship (USN-owned, civilian crews) |
| United States | United States Coast Guard | USCGC | United States Coast Guard Cutter |
| United States | United States Coast Guard | USCGD | United States Coast Guard Destroyer (not currently in use) |
| United States | National Oceanic and Atmospheric Administration | NOAAS | National Oceanic and Atmospheric Administration Ship |
| United States | 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 | United States Environmental Protection Agency | US EPA | United States Environmental Protection Agency; no "S" for "ship" is used |
| United States | 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 | 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 | United States Fish and Wildlife Service | US FWS | United States Fish and Wildlife Service; no "S" for "ship" used |
| United States | United States Lighthouse Service | USLHT | United States Lighthouse Tender (obsolete) |
| United States | United States Public Health Service | USPHS | United States Public Health Service; no "S" for "ship" used |
| United States | 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 |
| Venezuela | Venezuelan Navy | ARV | Armada República de Venezuela Not in use 1999 |
| Venezuela | Venezuelan Navy | 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) 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 |
| 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 | RČ | Raketni Čamac or Ракетни Чамац (English: Rocket boat), 1969–1992, named by Yugoslavia peoples heroes |
| 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 | VPBR | Veliki Patrolni Brod or Велики Патролни Брод (English: Big patrol ship), 1969–1992, named by Yugoslavia coastal towns |
| 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 | TČ | Torpedni Čamac or Торпедни Чамац (English: Torpedo boat), 1969–1992 |
| 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 | PČ | Patrolni Čamac or Патролни Чамац (English: Patrol boat), 1969–1992, named by mountains |
| 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 | PO | Pomoćni Oružar or Помоћни Оружар (English: Auxiliary аrmourer), 1969–1992 |
| 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 | RML | Rečni minolovac or Речни миноловац (English: River minesweepers), 1969–1992, named by places of WWII battles |
| 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 | RPB | Rečni patrolni brod or Речни патролни брод (English: River patrol boat), 1969–1992 |
| 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 | P | Podmornica or Подморница (English: Submarine), 1969–1992, named by rivers or human qualities |
| 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 | RЕ | Razarač Eskortni or Разарач Ескортни (English: Escort destroyer), 1969–1992 |
| 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 | PT | Pomoćni transportni or Помоћни транспортни (English: Auxiliary transport), 1969–1992 |
| 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 | DČ | Desantni čamci or Десантни чамци (English: Landing craft), 1969–1992 |

### Prefix conventions

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.

## In science fiction

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". 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" 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"