Use of Kodak Wratten number 12 'light green' safelight filter?

I've found a couple of these (one unused) while tidying my darkroom. I guess this filter is for some kind of panchromatic material, but not sure of suitability for my occasional RA4 work which I tend to do in the dark.

Use a WR13 for RA4 and none for any color film.

Use the directions for the WR13.

PE