Codes for different types of bases:

GY9.5 for 500 W and 1000 W lamps.  Used with lamps such as T18 and T26, or CP98, for focusable luminaires.		GX9.5 for 650 W  - 1200 W lamps. Used with lamps such as T11, T19, CP90, for focusable luminaires.		EMEP is the code of bases for 1,000 W - 1200 W lamps and for PAR lamps.
R7s for pencil lamps of various wattage.		G22 bases for 1200 W to 2500 W lamps. (CP92, CP93 are also used for these lamps).