We’re fortunate to include a great range of experience and interests among our membership. However, the knowledge gap between the services, generations, professionals and hobbyists can vary widely.
Click here for sources and other institutions’ glossaries.
Please note that formations may differ in size by country, service and specialism.
1SL – First Sea Lord (1904-present)
2iC – Second-in-Command
2Lt / 2nd Lt – Second Lieutenant
2SL – Second Sea Lord
AA – Anti-aircraft
AAA – Anti-aircraft artillery
AAC – Army Air Corps (1942-49, 1957-present)
AAS / AAC – Army Apprentices Schools later Army Apprentices Colleges (16 institutions open between 1924 and 2004)
AB – Able-bodied Seaman
ABM – Anti-Ballistic Missile
ABU – Armoured Beach Unit. Advance group on a beach landing to prepare and assist with the landing
ACC – Army Catering Corps (1941-93)
ACF – Army Cadet Force
AdC – Aide-de-Camp
Adm – Admiral
AEW – Airborne Early Warning
AFC – Air Force Cross
AGC – Adjutant General’s Corps (1992-present)
Air Group – An air force unit consisting of at least two squadrons. Commanded by a Group Captain
Air Wing – An air force unit consisting at least two groups. Commanded by a Wing Commander
ANZAC – Australian and New Zealand Army Corps
APC – Armoured Personnel Carrier. Wheeled or tracked vehicle to transport troops to a forward area and evacuate wounded
APTC – Army Physical Training Corps (1860-present)
AQMS – Artificer Quartermaster Sergeant (REME WO2)
Art – Artillery
ASM – Artificer Sergeant Major (REME WO1)
AWOL – Absent without leave
Battalion – A military unit consisting of 300-1,200 soldiers subdivided into a number of companies. Commanded by a Lieutenant Colonel.
Battery – An artillery unit typically consisting of six guns and their artillerymen and equipment. Equivalent of an infantry company.
BEF – British Expeditionary Force
BEM – British Empire Medal
BER – Beyond economic repair. When an item costs more to repair than to replace
BLR – Beyond local repair. When an item that is repairable but not by the unit holding it
Bn – Battalion
Bombardier – Corporal, Royal Artillery; Bomb aimer, RAF
Brig – Brigadier
Brigade – A major tactical military unit made up of three-to-six battalions, or two regiments. Commanded by a Colonel, Brigadier, Brigadier-General or Major-General.
BRNC – Britannia Royal Naval College, Dartmouth
Btry – Battery
BW – Biological weapons/warfare
C2 – Command and control
C3I – Command, control, communications and intelligence
Capt – Captain
CAS – Chief of the Air Staff (1918-present)
Cav – Cavalry
CBRN – Chemical, Biological, Radiological and Nuclear
CCF – Combined Cadet Force
Cdo – Commando
Cdr – Commander
Cdre – Commodore
CDS – Chief of the Defence Staff (1959-present)
CGS – Chief of the General Staff (1904-09 and 1964-present)
CIGS – Chief of the Imperial General Staff (1909-64)
C-in-C – Commander-in-Chief
CIWS – Close-in weapons system
CO – Commanding Officer
COBR – Cabinet Office Briefing Rooms
COBRA – Cabinet Office Briefing Room A
COD – Command Ordnance Depot. A depot suppling stores to the Army at home and overseas
CofS – Chief of Staff
Col – Colonel
Comb. Ops – Combined Operations. When two or more of the armed services operate under a single command
Company – A military unit made up of two or more platoons (30-250 soldiers). Commanded by a Captain or Major.
Continuity IRA / CIRA – Continuity Irish Republican Army. Nationalist paramilitary group (1986-present)
Corps – A major military unit made of two-to-five divisions (20,000-80,000 soldiers). Commanded by a Lieutenant General.
Corporal of the Horse – Sergeant, Household Cavalry
Cpl – Corporal
CQB – Close quarters battle
CSgt – Colour Sergeant
CSM – Company Sergeant Major
CSN – Confederate States Navy (1861-65)
CSS – Confederate States Ship
CVN – Nuclear-powered aircraft carrier
CW – Chemical weapons/warfare
CWGC – Commonwealth War Graves Commission (1960-present)
DCLI – Duke of Cornwall’s Light Infantry, British infantry (1881-1959)
DCM – Distinguished Conduct Medal
DDG – Guided-missile destroyer
DERR – Duke of Edinburgh’s Royal Regiment, British infantry (1959-94)
DFC – Distinguished Flying Cross
Division – A main military unit made up of multiple regiments or brigades (6,000-25,000 soldiers). Commanded by a Major General.
DLI – Durham Light Infantry, British infantry (1881-1968)
DoD – U.S. Department of Defense
Dragoons – Originally, mounted infantry named for their use of carbines (fire-breathing “dragons”).
DSC – Distinguished Service Cross
DSM – Distinguished Service Medal
DSO – Distinguished Service Order
DZ – Drop zone
ECM – Electronic countermeasures
EOD – Electronic Ordnance Disposal
FAA – Fleet Air Arm
FFG – Guided-missile frigate
FIDF – The Falkland Islands Defence Force (1892-1920, 1920-82, 1983-present)
FM – Field Marshal
FOB – Forward Operating Base
FOCAS – Flag Officer, Carriers and Amphibious Ships (1970-79)
FUSILIERS – The Royal Regiment of Fusiliers, British infantry (1968-present)
GC – George Cross
GCHQ – Government Communications Headquarters
Gen / Gnrl – General
GHQ – General Headquarters
GM – George Medal
GPMG – General purpose machine gun
GREN GDS – The Grenadier Guards, British infantry (1656-present)
GSC – The General Service Corps (1942-present)
HAC – Honorable Artillery Company, British artillery (1537-present)
HLI – Highland Light Infantry, British infantry (1881-1959)
HMG – Her/His Majesty’s Government
HMNB – Her/His Majesty’s Naval Base
HMS – Her/His Majesty’s Ship
HQ – Headquarters
Hussars – Light cavalry.
IG – The Irish Guards, British infantry (1900-present)
IJN – Imperial Japanese Navy (1868-1945)
Inf – Infantry
Int Corps – The Intelligence Corps (1914-29, 1940-present)
IRA – Irish Republican Army. A name used by multiple nationalist paramilitary groups since 1919
IWGC – Imperial War Graves Commission (1917-60)
IWM – Imperial War Museum
JHC – Joint Helicopter Command
JTF – Joint Task Force
KIA – Killed in action
KOSB – King’s Own Scottish Borderers, British infantry (1689-2006)
KOYLI – King’s Own Yorkshire Light Infantry, British infantry (1881-1968)
KRH – The King’s Royal Hussars, British cavalry(1992-present)
Kriegsmarine – German Navy (1935-45)
KRRC – King’s Royal Rifle Corps, British infantry (1756-1966)
KSLI – King’s Shropshire Light Infantry, British infantry (1881-1968)
LAC – Leading Aircraftsman
LAD – Light aid detachment. A REME detachment posted to an army unit to do first line repairs. Size depends on the unit: a sergeant plus 6 or 7 men, or a captain and over 100 men in an armoured regiment
LANCS – The Duke of Lancaster’s Regiment, British infantry (2006-present)
LCM – Landing Craft Mechanised. Carried in the dock of an LPD
LCpl – Lance Corporal
LCVP – Landing craft vehicle and personal. Carried on davits in-board on the side of an LPD
LD – The Light Dragoons, British cavalry(1992-present)
LG – The Life Guards, British cavalry(1922-present)
LPD – Landing Platform Dock. Also known as assault ships (e.g. HMS Albion and HMS Fearless)
LRDG – Long Range Desert Group (1940-45)
LSL – Landing Ship Logistic. Round Table class ships operated by the RFA (e.g. Sir Bedivere, Sir Galahad, Sir Geraint, Sir Lancelot, Sir Percivale, Sir Tristram)
LST – Landing Ship Tank
Lt – Lieutenant
Lt Col – Lieutenant Colonel
Lt Gen – Lieutenant General
Lt Inf – Light Infantry
Luftwaffe – German Air Force (1933-46)
Maj – Major
Maj Gen – Major General
MBT – Main Battle Tank
MC – Military Cross
MEDEVAC – Medical Evacuation
MERC / MERCIAN – The Mercian Regiment, British infantry (2007-present)
MEXE – Military Engineering Experimental Establishment (1946-70)
MEXE float – Pontoon float carried on the outside of the hull of an LSL. Can be driven by outboard or used as a jetty
MGC – Machine Gun Corps
Mid – Midshipman
MM – Military Medal
MoD – Ministry of Defence
MP – Military Police (see RMP)
NAAFI – Navy, Army and Air Force Institute
NAM – National Army Museum
NATO – North Atlantic Treaty Organisation
NCO – Non-Commissioned Officer
New IRA – New Irish Republican Army. Nationalist paramilitary group (2012-present)
OC – Officer Commanding
OiC – Officer in Command
OIRA – Official Irish Republican Army. Nationalist paramilitary group (1969-72/late-1990s)
OP – Observation Post
OpSec – Operational Security
OTC – Officer Training Corps
PARA – The Parachute Regiment, British airborne infantry (1942-present)
PJHQ – Permanent Joint Headquarters
PLA – People’s Liberation Army (China)
PLAN – People’s Liberation Army Navy (China)
POW – Prisoner of War
PPCLI – Princess Patricia’s Canadian Light Infantry (1914-present)
Provisional IRA / PIRA – Provisional Irish Republican Army. Nationalist paramilitary group (1969-1997/2005)
PSNI – Police Service of Northern Ireland (2001-present)
PWRR – Princess of Wales’s Royal Regiment, British infantry (1992-present)
QARANC – Queen Alexandra’s Royal Army Nursing Corps (1949-present)
QDG – 1st The Queen’s Dragoon Guards, British cavalry. Also known as the Welsh Cavalry (1959-present)
QF – Quick firing
QM – Quartermaster
QOY – The Queen’s Own Yeomanry, British cavalry (1971-present)
QRF – Quick Reaction Force
QRH – The Queen’s Royal Hussars, British cavalry (1993-present)
R ANGLIAN – The Royal Anglian Regiment, British infantry (1964-present)
R IRISH – The Royal Irish Regiment, British infantry (1992-present)
R SIGS / R SIGNALS – The Royal Corps of Signals (1920-present)
R WELSH – The Royal Welsh, British infantry (2006-present)
RA – The Royal Regiment of Artillery (1716-present)
RAC – Royal Armoured Corps, British cavalry
RAdm – Rear Admiral
RAF – Royal Air Force (1918-present)
RAMC – The Royal Army Medical Corps (1898-present)
RANGER – The Ranger Regiment, British infantry (2021-present)
RAVC – The Royal Army Veterinary Corps (1796-present)
RCM – Regimental Corporal Major. WO1, Household Cavalry
RCT – Royal Corps of Transport (1965-93)
RDG – The Royal Dragoon Guards, British cavalry (1992-present)
RE – The Corps of Royal Engineers (1716-present)
Real IRA / RIRA – Real Irish Republican Army. Nationalist paramilitary group (1997-2012)
Regiment – A military unit whose role and size varies by country and/or function. Often made up of multiple battalions. Commanded by a Lieutenant Colonel.
REME – The Corps of Royal Electrical and Mechanical Engineers (1942-present)
RFA – Royal Field Artillery; Royal Fleet Auxiliary
RFC – Royal Flying Corps (1912-18)
RG – The Royal Gibraltar Regiment (1958-present)
RGBW – Royal Gloucestershire, Berkshire & Wiltshire Regiment, British infantry (1994-2007)
RGJ – Royal Green Jackets, British infantry (1966-2007)
RGR – The Royal Gurkha Rifles, British infantry (1994-present)
RHA – Royal Horse Artillery
RHG/D – Royal Horse Guards and 1st Dragoons, British cavalry. Also know as the Blues and Royals (1969-present)
RHQ – Regimental Headquarters
RIFLES – The Rifles, British infantry (2007-present)
RLC – The Royal Logistic Corps (1993-present)
RM – Royal Marines (1664-present)
RMA – Royal Military Academy, Sandhurst
RMLI – Royal Marine Light Infantry
RMP – Royal Military Police (1926-present)
RMR – Royal Marines Reserve
RN – Royal Navy
RNAS – Royal Naval Air Service (1914-18); Royal Naval Air Station
RNR – Royal Naval Reserve
RoE – Rules of Engagement
RP – Regimental Police. Only have authority over regimental personnel
RSM – Regimental Sergeant Major
RSME – Royal School of Military Engineering, Chatham
RTR – Royal Tank Regiment, British cavalry (1917-present)
RUC – Royal Ulster Constabulary (1922-2001)
RWY – The Royal Wessex Yeomanry, British cavalry (1971-present)
RY – The Royal Yeomanry, British cavalry (1967-present)
SAM – Surface-to-Air Missile
SAR – Search and Rescue
SAS – Special Air Service (1941-present)
SASC – The Small Arms School Corps (1853-present)
SBS – Special Boat Squadron (1940-present)
SCM – Squadron Corporal Major. WO2, Household Cavalry
SCOTS – The Royal Regiment of Scotland, British infantry (2006-present)
SCOTS DG – The Royal Scots Dragoon Guards, British cavalry (1971-present)
SeAL – Sea, Air, Land
SG – The Scots Guards, British infantry (1642-present)
Sgt – Sergeant
SIB – Special Investigation Branch. Part of the Royal Military Police
SitRep – Situation Report
SF – Special Forces
SLR – Self-loading rifle
SMG – Sub-machine gun
SMHS – Salisbury Military History Society (2019-present)
SNIY – The Scottish and North Irish Yeomanry, British cavalry (2014-present)
SOE – Special Operations Executive (1940-46)
SP – Shore Patrol. Naval patrol used when a ship is in port to keep order on shore. Normally consisting of a Petty Officer and three Ratings
SP gun – Self propelled gun. Often on tracks and armoured with a turret that has limited travers of only a few degrees
Sqn – Squadron
Squadron (army) – A sub-unit of a cavalry, engineer or armoured regiment. Equivalent of an infantry company
Squadron (air force) – A unit consisting of three or four flights (12-24 aircraft). Commanded by a Squadron Leader or Wing Commander
SRR – The Special Reconnaissance Regiment (2005-present)
STOVL – Short-Take-Off and Vertical Landing
TA – Territorial Army, the UK’s army reserve (1921-1967 and 1979-2014)
TAVR – Territorial and Army Volunteer Reserve (1967-1979)
TCV – Troop carrying vehicle. Variants of the Bedford QL fitted with padded seats. (1941-60s)
UAS – University Air Squadron
UAV – Unmanned Aerial Vehicle
UDA – Ulster Defence Association. Loyalist paramilitary group (1971-94/2007)
UDR – Ulster Defence Regiment (1970-92)
UKLF – United Kingdom Land Forces. Controls British Army worldwide
UN – United Nations
URNU – University Royal Naval Unit
USAAF – United States Army Air Force
USAF – United States Air Force
USMC – United States Marine Corps (1798-present)
USN – United States Navy
USS – United States Ship
UVF – Ulster Volunteer Force. Loyalist paramilitary group (1966-1994/2007)
UW – Urban Warfare
UXB – Unexploded bomb
VAdm – Vice Admiral
VC – Victoria Cross
WAAC – Women’s Auxiliary Army Corps
WAAF – Women’s Auxiliary Air Force
Waffen-SS – Armed branch of the Nazi Party’s Schutzstaffel (1933-45)
Wehrmacht – German armed forces (1935-45)
WG – Welsh Guards, British infantry (1915-present)
Wing – An air force unit consisting at least two groups. Commanded by a Wing Commander
WMD – Weapons of Mass Destruction
WO1 – Warrant Officer class 1. Warrant Officers are the highest rank of NCOs in the British Army
WO2 – Warrant Officer class 2. Warrant Officers are the highest rank of NCOs in the British Army
WRNS – Women’s Royal Naval Service
WW1 – World War One (1914-18)
WW2 – World War Two (1939-45)
XO – Executive Officer
Yeomanry – Reserve cavalry
YORKS – The Yorkshire Regiment, British infantry (2006-present)
