Where I work, there’s a signal that gets used in the women’s restroom whenever one of the paper towel dispensers runs out of paper. A scrap of paper towel (presumably the last scrap) is stuck on to the handle of the dispenser. It’s been this way for twenty years at least, and everyone, even the janitorial staff, knows its meaning. It makes sense; it’s not like you’re necessarily going to have a notepad and a pen with which to write a note. This evolved organically; there’s no section in the department manual or memo on our intranet about it. Believe me, I’d know.
The other day I went into to restroom and saw that on the door of the far stall, a scrap of paper towel had been tucked into the door. I looked at it for a couple of seconds. I mean, the stall doesn’t have a towel dispenser. Unless this is a way to let us know that there is no toilet paper.