What is special name suffix "/FR"?
This special name encoding reference means: Frosted glass. Typically applied to outside of glass, but frost coat could be applied to bulb inside glass.
Also see /IF and /CL
references for this page: /FR, FROSTED, FROSTED GLASS
references to this page: /C, /HF, /IF, /LF, ENCODINGS PHILIPS OLD BULBS