graphic warning devices designed to give the hazard class or division of the dangerous goods carried in a vehicle or railroad car

NOTE There are different placards for each class or division. Placards are colour coded and are at least 10,8 in (273 mm) on a side and must be displayed on all four sides of the vehicle. Placards display the hazard class number in the bottom corner. Some vehicles are required to display more than one placard; some will display three or more.