Historical
NEMA ANSI C136.9:2003
For roadway and area lighting equipment - socket support assemblies for metal heads - mechanical interchangeability
Covers the following equipment for use in metal heads that are in accordance with the latest revision of ANSI C136.6: high-intensity discharge lamp ballast and socket assemblies, and mogul and medium multiple incandescent lamp socket and support assemblies.
NEMA: National Electrical Manufacturers Association [nema]