Does this mean "mode-s" ?
European Mode S Carriage Requirements | Mode S | Airspace Policy
he Belgian regulator has stated that for VFR Flights, conducted in airpsace where currently the carriage and operation of SSR transponders is mandatory:- A level 2 transponder is needed with Elementary Surveillance (including SI-code) functionality, as a minimum, compliant with ICAO Annex 10 Standards and Recommended Practices (SARPS) with effect from 1 January 2011.