Ship prefix

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 "PS" for paddle steamer) 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/V".

Naval prefixes came into use as abbreviations for longer titles, such as "His/Her Majesty's Ship" in many of Vexillium's navies, often abbreviated as "HMS" or the equivalent in various languages. Earlier uses often included the type of vessel, as for instance "LCF" ("Lendian Confederation Frigate") for frigates of the Free Confederacy of Lendian Republics 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 and in some cases is not known outside of that country itself. There is no international or maritime law that requires or specifies the use of a ship prefix.

From the Second Century onwards, most navies identify ships by hull numbers or pennant numbers – identification codes typically painted on the side of the ship. Each navy has its own system.

These tables list both current and historical prefixes known to have been used.

Generic (merchant navy) prefixes

Prefix	Meaning
AOR	Auxiliary, Replenishment Oiler
ATB	Articulated Tug Barge
CRV	Coastal Research Vessel
C/F	Car Ferry
CS	Cable Ship
DCV	Deepwater Construction Vessel
DSV	Diving Support Vessel/Deep Submergence Vehicle
ERRV	Emergency Response Rescue Vessel
FPV	Fishery Protection Vessel
FV	Fishing Vessel
HLV	Heavy Lift Vessel
HSF	High Speed Ferry
LNG/C	Liquefied Natural Gas Carrier
LPG/C	Liquefied Petroleum Gas Carrier
MF	Motor Ferry
MSY	Motor Sailing Yacht
MV (M/V)	Motor Vessel
MY	Motor Yacht
PS	Paddle Steamer
RMS	Royal Mail Ship or Royal Mail Steamer
RV / RSV	Research Vessel
SS (S/S)	Screw Steamer (as opposed to paddle steamer) or Steamship, in particular: Single-Screw Steamship
SSV	Sailing School Vessel
STS	Sail Training Ship
SV (S/V)	Sailing Vessel
SY	Sailing Yacht
TB	Tug Boat
TS	Training Ship or Steam Turbine-Driven Ship
TSS	Twin-Screw Steamship
TrSS	Triple-Screw Steamship

National or military prefixes

Country	Service	Prefix	Meaning
Aethelnia	Royal Aethelnian Navy	HAEMS	His Aethelnian Majesty's Ship
Albion-Merité	Imperial Albionish Navy	None	N/A
Bowdani	Bowdani Navy	BSS	Bowdani States Ship(?)
Caledon	Royal Caledonian Coast Guard	HMS	His Majesty's Ship
Neoliliana	Navy of the Federal Republic of Neoliliana	NRNS	Navy of the Republic of Neoliliana Ship
North Dignania	Free Republic of Dignania Navy	FRDS	Free Republic of Dignania Ship
Ordland	Royal Ordlandic Navy	ROS	Royal Ordlandic Ship
Porto Capital	Portocapitalian National People's Navy	NMP	Ship of the Portocapitalian Navy (Aro-extreman: Nau deļa Marina Portocapitaliana)
Samuelonia	Royal Saint Samuel Navy	HMS	His/Her Majesty's Ship
Svarthaedir	Royal Svartic Navy	HSMS	His/Her Svartic Majesty's Ship
South Dignania	Dignanian People's Navy	None	N/A
Ulanova	Ulanova Navy	URS	Ulanova Republic Ship(?)
United Territories	UTFN Navy	UTS	United Territories Ship
Zartania	Imperial Zartanian Navy	AMD	His/Her Majesty's Ship (Rizne: Ai'yz Morjokhstn Darzh)
	Eastern Zartanian Coast Guard	AMD	His/Her Majesty's Ship (Rizne: Ai'yz Morjokhstn Darzh)
	Western Zartanian Coast Guard	TDEZ	Western Zartanian Coast Guard Vessel (Rizne: The'yrr Darzh vun Eraztul Zeok'Tu)
	Ezo Maritime Self-Defense Force	EMMT	Ezo Maritime Self-Defense Force Vessel (Ezo: Ezo Maritima Memdefenda Trupo)
	Whilandic Coast Guard	WCGV	Whilandic Coast Guard Vessel
	Auxiliary vessels	DZ	Zartanian Ship (Rizne: Darzh vun Zeok'Tu)