Four corners
When you're in an elevator, and someone screams FOUR CORNERs, punches someone in their balls, and everyone instantly protects their own balls, and presses against a wall.
Example:
*peace in Elevator
Guy: FOUR CORNERS
*punches guy 2 in balls
*everyone guards their own and turns towards a wall
*peace in Elevator
Guy: FOUR CORNERS
*punches guy 2 in balls
*everyone guards their own and turns towards a wall