The abbreviation is derived from the name of a Canadian croquet team (i.e., "Team Keep India British") which frequented the Royal Canadian Yacht Club in the early years of the present century.
Usage now peculiar to Brasenose College, Oxford.
"I say, you're off to the union now, aren't you?"
"Well, give those socialists what for."
Or in a text message:
"Bah! Brideshead is on in the MCR now. Care to join?"
"It would be my distinct pleasure. K.I.B."