This standard describes a system for classification of beam patterns and beam angles of reflector lamps. Also a method of describing light output is defined.

Reflector lamps are considered to be those lamps having a reflective coating applied to the reflector part of the bulb or a reflector permanently attached to the bulb with the reflector at least partially controlling the light flux distribution. Partial reflector lamps are also covered. Both symmetrical and asymmetrical beams can be classified. Lamps with various kinds of light sources are covered.