Yes,
REStricted
INtensity would sound about right. The ordinary nav lights had a dim/bright selection and the position lights were on a separate circuit with no dim selection; I can't remember what rating the filaments were.
Edit: On another BB they were discussing Mosquito lights and the Resin Lights on a Mossie in a US museum were mentioned as having a metal cover with a vertical slit that restricted the viewing angle of the light to within a narrow angle directly to the rear of the aircraft. I never saw such covers, but that configuration would be logical in wartime conditions.
REStricted
INcidence perhaps?