White Clean Air Stickers are issued to vehicles that meet California's super ultra-low emission vehicle (SULEV) standard for exhaust emissions and the federal inherently low-emission vehicle (ILEV) evaporative emission standard. Such stickers allow the vehicle to be operated by a single occupant in the High Occupancy Vehicle (carpool or diamond) lanes of California's freeways. This particular sticker was photographed on a Honda FCX hydrogen fuel cell vehicle (leased prototype). Los Angeles, California, USA. August 2008