In all Nat Service units I served in 1951-52, "jankers" meant CB; which stood for Confinement to Barracks, but meant a lot more than just what the name implies: involving, not only being forbidden to leave the barracks, but also early morning reporting to the guardroom {without benefit of an 'early call'} for inspection by the sergeant guard-commander, banning from the canteen at morning NAAFI-break, parading behind the guard at evening guard-mounting in full Battle-Order or Field Service Marching Order [i.e. all packs, belts, cross-straps &c, all of which had to be in high state of blanco-and-brass·polish bull], followed by two hours of busywork fatigues of the scrubbing or spud-bashing kind. It was no joke, believe me...

~M~