San Francisco Fire Code § 504.5 Identification on Steel Doors

When rolling steel shutters or similar steel doors are located on any building or structure and there is no easily accessible opening giving access to the building or structure within 25 feet (7620 mm) of the shutter or door, an approved marking shall be affixed on the shutter or door designating or outlining an area which, when removed by burning or cutting, will give access to locking devices, hoisting chains or other devices that control the operation of the shutter or door.