What is the "meatball flag" in Formula One?

A mechanical black flag is a black flag with an orange disc in its center which indicates that a vehicle is being summoned to the pits due to serious mechanical problems or loose bodywork that presents a risk to other competitors. At some road racing events, it is used to summon the vehicle to the pits to inform the driver of violation "maximum sound levels". Also known as the 'Meatball' flag.