Public Leaning Post. Does not exist in real life; merely referred to by any indigant person whom someone else of perfectly sound physique tries to lean against merely out of laziness.
Lazy dude, resting his broad shoulder against his slight-figured girlfriend while they're standing at a bus stop: Aahhh... convenient back-rest!
Girl, giving him an indignant shove: Hey --- get OFFA me, ya big lugg! I'm not a PLP!