ASU – Active Service Unit.

BOX – MI5 and MI6, referred to as such because their address was a box number in Curzon Street, London.

CAT – Civil Administration Team, PIRA’s internal security unit.

CTR – Close Target Recce (Reconnoitre).

Det – Military Specialist surveillance units detached from their own regiment.

DMSU – Divisional Mobile Support Unit.

DFC – Duty Flight Commander.

E – Special Branch department within police.

E3 – Special Branch’s agent handling department.

E4 – Special Branch’s surveillance department.

E4A – Covert surveillance unit within Special Branch.

HMSU – Headquarters Mobile Support Unit.

IO – Head of PIRA’s intelligence gathering units.

INLA – Irish National Liberation Army.

IPLO – Irish People’s Liberation Organisation.

LP – Listening Post.

OP – Observation Point.

OTR – On the run.

PAC – Provisional Army Council, PIRA’s leading body. Has seven members.

PIRA – Provisional Irish Republican Army.

Recce – to reconnoitre a target.

RUC – Royal Ulster Constabulary.

Sinn Fein – Political wing of PIRA.

SDLP – Social and Democratic Labour Party, largest Nationalist party in Northern Ireland.

SAS – Special Air Service.

SSU – Special Support Units (uniformed Special Branch).

TCG – Tasking Coordination Group, comprising of SAS, MI5, Special Branch, and Military intelligence officers.

UCBT – Undercar booby-trap device.

UDA – Ulster Defence Association (loyalist).

UDR – Ulster Defence Regiment – amalgamated with Royal Irish Rangers to become the Royal Irish Regiment (R.I.R.) in 1992.

UVF – Ulster Volunteer Force (loyalist).

VCP – Vehicle Check Point.