My sister has a little recording/rehearsal building she calls Kathronia. Yesterday she was in there practicing for a recording session. You could tell she was working because she has a red recording light in there.
“Where’s your sister?” asked my dad.
“She’s in there rehearsing,” I answered. “You can see she has the red light on.”
“Oh yeah,” he said. “That’s her Fuck Off light.”
Henceforce those things shall be known as Fuck Off lights!