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.
Lazydude, 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!