Glossary of terms and abbreviations

  • a (10)
  • b (5)
  • c (4)
  • d (4)
  • e (1)
  • g (5)
  • h (2)
  • i (3)
  • l (1)
  • m (1)
  • n (1)
  • o (4)
  • p (4)
  • q (1)
  • r (8)
  • s (5)
  • t (3)
  • w (1)
Name Explanation

Anti-aircraft. Also known as Ack-Ack




Air raid precautions


Auxiliary Territorial Service. The women's branch of the British Army during the Second World War. A number of INstation wireless operators were ATS officers and subalterns who had volunteered for this task.  


Auxiliary Units. Specially trained, highly secret units created by the government during WW2, with the aim of resisting the expected occupation of the UK by Nazi Germany. AU operational patrols were composed entirely of civilians. 

Aux Units Mk1

A box containing a selection of explosives and incendiaries, issued to all Auxiliary Units operational patrols. There was an improved version called Aux Units Mk2.

Auxiliary Units Scout Sections

Consisted of small units (12 men) of regular soldiers who were tasked with assisting and training Auxiliary Units operational patrols. There were commonly two Scout Sections per County.  

Auxiliary Units Signals

Consisted of regular soldiers from the Royal Corps of Signals, setting up, operating and maintaining the secret wireless network, under the command of Major RNA Jones, Auxiliary Units Signals, GHQ Home Forces. 

Auxiliary Units Signals Workshop

Under command of Capt KM Ward designed, developed, produced, repaired and maintained wireless sets for use by Special Duties Branch. 


Member of an Auxiliary Units operational patrol


Brigade. Military unit, typically composed of three to six battalions and supporting elements. 


Battalion. Military unit of around 300–1,200 soldiers usually consisting of between two and seven companies and typically commanded by either a lieutenant colonel or a colonel. Several battalions are grouped to form a regiment or a brigade. 


British Resistance Archive (This website managed by CART)

British Army Ranks

British Army personnel are ranked according to level, from the lowest (privates) to the highest (generals). Above private soldiers there are three types of officer: non-commissioned officers, warrant officers, and commissioned officers. The term used to refer to all ranks below officers is Other Ranks (ORs). It includes Warrant Officers, Non-commissioned officers (NCOs) and ordinary soldiers with the rank of Private or regimental equivalent. There are two abbreviations for the rank of Sergeant: Sgt and Sjt (the latter originating from Serjeant, a generally obsolete spelling of Sergeant).


British Resistance Organisation Museum, Parham Airfield Museum, Parham, Framlingham IP13 9AF, Suffolk 


County Information Officer (Old title awarded to a CART researcher in a given county - now obsolete.) All welcome!


Commanding Officer


Company. Military unit, typically consisting of 75-200 soldiers.


Central Supply Depo

Dead letter drops

Used by civilian spies or couriers of the Special Duties Branch for leaving messages which were picked up and distributed by runners.


Division. Military unit, typically consisting of between 10,000 and 30,000 soldiers. 

Div HQ

Divisional headquarters


Defence of Britain Project. Volunteers of the DoB project recorded nearly 20,000 20th-century military sites. 


Chemical toilet

G2 Officer in the staff branch of military headquarters. G2 Branch was responsible for security and intelligence.

Group Commander. A GCO was in command of a group of Auxiliary Units operational patrols. 


General Headquarters. GHQ Auxiliary Units was based at Coleshill House, Wiltshire, from July 1940 to January 1945. 

GHQ Line

General Headquarters Line. A defence line built in the UK during WW2 to contain an expected German invasion.


General Post Office


Home Guard. A defence organisation of the British Army during WW2. Operational from 1940 until 1944, the HG comprised 1.5m local volunteers.




INstations formed part of the wireless network commanded by Major RNA Jones of Auxiliary Units Signals (GHQ Home Forces). They commonly consisted of an above-ground hut designed to look like a meteorological hut (for every day use) and a concealed dugout (sometimes referred to as Zero-station) nearby, intended to be used in the event of an invasion. Sometimes also referred to as Control stations, they commonly housed two wireless sets, used to communicate with a number of OUTstations within one particular network, as well as with neighbouring INstations. The wireless sets were operated either by ATS or by Auxiliary Units Signals staff.


Intelligence Officer


Imperial War Museum, Lambeth Road London SE1 6HZ


Local Defence Volunteers. In July 1940, on the instructions of Prime Minister Winston Churchill, the name was changed to Home Guard.


Military Intelligence, Section 6 (see SIS), Based at Vauxhall Cross, London SE1 1BD


Non-commissioned officer


Operational base. Dugout used by Auxiliary Units operational patrols and Scout Sections.


Officer Cadet Training Unit


Observation post. Lookout used by Auxiliary Units operational patrols and Scout Sections (usually associated with an OB).


OUTstations formed part of the wireless network commanded by Major RNA Jones of Auxiliary Units Signals (GHQ Home Forces). Every OUTstation consisted of a wireless set operated by a civilian, providing the local INstation with the latest intelligence. See also SDS. 


A group of Auxiliers recruited to operate clandestinely in their own locality behind enemy lines. Each patrol had their own OB.

Pers coms

Personal communications


The official name of this special reconnaissance unit, which was first formed in 1939, was GHQ Liaison Regiment.


Public Record Office (see TNA/The National Archives)


Quartermaster. Officer responsible for stores and supplies.


Royal Air Force


Royal Army Service Corps. Now called the Royal Logistics Corps, the RASC was responsible for supply and transport in the army.


Royal Corps of Signals. Responsible for providing battlefield communications and information systems essential to all operations. A number of RCS officers and other ranks served in Auxiliary Units Signals, setting up and maintaining the secret wireless network.


Royal Engineers. The Corps of Royal Engineers provides military engineering and other technical support to the British Armed Forces. Special RE units assisted with the construction and wiring of operational bases and IN-stations of the wireless network