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
2iC – Second-in-Command
2Lt / 2nd Lt – Second Lieutenant
2SL – Second Sea Lord
AA – Anti-aircraft
AAA – Anti-aircraft artillery
AAC – Army Air Corps
ABM – Anti-Ballistic Missile
Adm – Admiral
AEW – Airborne Early Warning
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
Art – Artillery
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
Bn – Battalion
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
Cav – Cavalry
CBRN – Chemical, Biological, Radiological and Nuclear
Cdo – Commando
Cdr – Commander
Cdre – Commodore
CDS – Chief of the Defence Staff
CGS – Chief of the General Staff
CIWS – Close-in weapons system
CO – Commanding Officer
COBR – Cabinet Office Briefing Rooms
COBRA – Cabinet Office Briefing Room A
CofS – Chief of Staff
Col – Colonel
Company – A military unit made up of two or more platoons (30-250 soldiers). Commanded by a Captain or Major.
Corps – A major military unit made of two-to-five divisions (20,000-80,000 soldiers). Commanded by a Lieutenant General.
Cpl – Corporal
CQB – Close quarters battle
CSM – Company Sergeant Major
CSN – Confederate States Navy (1861-65)
CSS – Confederate States Ship
CVN – Nuclear-powered aircraft carrier
CW – Chemical weapons/warfare
DDG – Guided-missile destroyer
DERR – Duke of Edinburgh’s Royal Regiment (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.
DoD – U.S. Department of Defense
Dragoons – Originally, mounted infantry named for their use of carbines (fire-breathing “dragons”).
DZ – Drop zone
ECM – Electronic countermeasures
EOD – Electronic Ordnance Disposal
FAA – Fleet Air Arm
FFG – Guided-missile frigate
FOB – Forward Operating Base
GCHQ – Government Communications Headquarters
GHQ – General Headquarters
GPMG – General purpose machine gun
HMG – Her/His Majesty’s Government
HMNB – Her/His Majesty’s Naval Base
HMS – Her/His Majesty’s Ship
HQ – Headquarters
Hussars – Light cavalry.
IJN – Imperial Japanese Navy (1868-1945)
Inf – Infantry
IWM – Imperial War Museum
JHC – Joint Helicopter Command
JTF – Joint Task Force
KOYLI – King’s Own Yorkshire Light Infantry (1881-1968)
Kriegsmarine – German Navy (1935-45)
LCpl – Lance Corporal
LRDG – Long Range Desert Group (1940-45)
Lt – Lieutenant
Lt Inf – Light Infantry
Luftwaffe – German Air Force (1933-46)
Maj – Major
MBT – Main Battle Tank
MC – Military Cross
MEDEVAC – Medical Evacuation
Mid – Midshipman
MM – Military Medal
MoD – Ministry of Defence
NAM – National Army Museum
NATO – North Atlantic Treaty Organisation
NCO – Non-Commissioned Officer
OiC – Officer in Command
OP – Observation Post
OpSec – Operational Security
OTC – Officer Training Corps
PJHQ – Permanent Joint Headquarters
PLA – People’s Liberation Army (China)
PLAN – People’s Liberation Army Navy (China)
PWRR – Princess of Wales’s Royal Regiment (1992-present)
QRF – Quick Reaction Force
RA – Royal Artillery
RAC – Royal Armoured Corps
RAdm – Rear Admiral
RAF – Royal Air Force (1918-present)
RE – Royal Engineers
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 – Royal Electrical and Mechanical Engineers
RFC – Royal Flying Corps (1912-18)
RFA – Royal Field Artillery; Royal Fleet Auxiliary
RGBW – Royal Gloucestershire, Berkshire & Wiltshire Regiment (1994-2007)
RGJ – Royal Green Jackets (1966-2007)
RHA – Royal Horse Artillery
RHQ – Regimental Headquarters
RLC – Royal Logistic Corps (1993-present)
RM – Royal Marines (1664-present)
RMA – Royal Military Academy, Sandhurst
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
RSM – Regimental Sergeant Major
RSME – Royal School of Military Engineering, Chatham
RTR – Royal Tank Regiment (1939-present)
RUC – Royal Ulster Constabulary (1922-2001)
SAM – Surface-to-Air Missile
SAR – Search and Rescue
SAS – Special Air Service (1941-present)
SBS – Special Boat Squadron (1940-present)
SeAL – Sea, Air, Land
SitRep – Situation Report
SF – Special Forces
SLR – Self-loading rifle
SMG – Sub-machine gun
SMHS – Salisbury Military History Society (2019-present)
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
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)
UAS – University Air Squadron
UAV – Unmanned Aerial Vehicle
UDR – Ulster Defence Regiment (1970-92)
UN – United Nations
URNU – University Royal Naval Unit
USMC – United States Marine Corps (1798-present)
USN – United States Navy
USS – United States Ship
UW – Urban Warfare
VAdm – Vice Admiral
VC – Victoria Cross
Waffen-SS – Armed branch of the Nazi Party’s Schutzstaffel (1933-45)
Wehrmacht – German armed forces (1935-45)
Wing – An air force unit consisting at least two groups. Commanded by a Wing Commander
WMD – Weapons of Mass Destruction
WW1 – World War One (1914-18)
WW2 – World War Two (1939-45)
XO – Executive Officer
Yeomanry – Reserve cavalry