This Preliminary Information communication provides information to the technician to help determine if the vehicle is equipped with factory or aftermarket Compressed Natural Gas, Liquefied Petroleum Gas, or Bi-Fuel Systems. Technician will check for the Vehicle Emission Control Information Label. By using the engine Regular Production Option Code as well as the Vehicle Emission Control Information Label, technician can confirm the vehicle has a factory installed alternative fuel system or who the manufacturer is of the aftermarket fuel system.