/M or /L on an ICAO flight plan

The/L or /M on an ICAO Format flight plan has nothing to do with RVSM, Transponders, or equipment.
The /L or /M you are looking at on the ICAO Format flight plan is for Wake Turbulence Category.
The /L means you are Light weight category (Less than 15,500 lbs). The /M means you are Medium weight category (More than 15,500 lbs).

For more information on ICAO codes, see our ICAO help page here.