Although I never do it myself due to it being frowned upon in apartment buildings, I do like a bit of grilled food. This is a sign in one of the elevators in my aforementioned apartment building.
Among other useful tips and safety advice, it recommends not grilling doors. I heartily agree. Much better long and slowly braised I find. With soy sauce and ginger, of course. And a chilli dip.
Why they are giving cooking lessons in elevators baffles me.
The Chinese reads 禁止扒门 (jìn zhǐ bā mén) which means "Grasping the doors forbidden".