This recommended practice is intended to provide uniform nomenclature and definitions for the primary levels of vehicle identification, with particular application to passenger cars.

This SAL Recommended Practice is intended to provide uniform nomenclature and definitions for the primary levels of vehicle identification, with particular application to trucks.While this specific terminology applies only to trucks, work is in progress to develop supplementary nomenclature and definitions pertaining to other commercial vehicle terms and to terms presently used interchangeably in passenger car, truck, or other commercial vehicle applications. The supplementary terms will be covered in subsequent revisions to this recommended practice.