Also known as the "meatball flag", in auto racing, the starter will wave this flag to tell a particular driver to get off the track due to a mechanical problem or other internal hazard in his or her vehicle.  Like the black flag, this flag is displayed with the number of the car in question.  Of the major racing series, only Formula One is known to use this flag.
No machine-readable source provided. Own work assumed (based on copyright claims).
No machine-readable author provided. Denelson83 assumed (based on copyright claims).