In February 1944, the British Army fortuitously made the "general service" cap (a sort of oversized beret made from serge wool) the new standard undress cap.
The Royal Irish Rangers (formed in 1968 by the amalgamation of the remaining regiments in the North Irish Brigade, The Royal Inniskilling Fusiliers, The Royal Ulster Rifles and The Royal Irish Fusiliers) were granted the wearing of the caubeen with the Irish Fusiliers' green hackle.