"The Ulster Special Constabulary (USC; commonly called the "B-Specials" or "B Men") was a quasi-military reserve special constable police force in Northern Ireland. It was set up in October 1920, shortly before the partition of Ireland. It was an armed corps, organized partially on military lines and called out in times of emergency, such as war or insurgency. It performed this role in 1920–22 during the Irish War of Independence and in the 1950s, during the IRA Border Campaign.

During its existence, 95 USC members were killed in the line of duty. Most of these (72) were killed in conflict with the IRA in the years 1921 and 1922. Another 8 died during the Second World War, in air raids or IRA attacks. Of the remainder, most died in accidents but two former officers were killed during the Troubles in the 1980s.

The force was almost exclusively Ulster Protestant and as a result was viewed with great mistrust by Catholics. It carried out several revenge killings and reprisals against Catholic civilians in the 1920–22 conflict. Unionists generally supported the USC as contributing to the defence of Northern Ireland from subversion and outside aggression.

The Special Constabulary was disbanded in May 1970, after the Hunt Report, which advised re-shaping Northern Ireland's security forces to attract more Catholic recruits and disarming the police. Its functions and membership were largely taken over by the Ulster Defence Regiment and the Royal Ulster Constabulary." - Wikipedia