IF at a given point of time, ie during a class "Lads-" are currently "-off" (ie LADS OFF) then one might want to turn lad's on by a cry of "lads on"
Guy2: "LADS ON!"
Guy1: "Fucking maggot dardi gibbon aye!? TRRUUUU"
Guy2: "LADS OFF!"
Guy1: " ill probly get a D if i dont finish it ...