RACE Radar Radio-alfabet Radiogolf Radio Regulations Radio roepnaam Radiospectrum Radiospectrumbeschikking RADIUS Rake ontvanger RDS RDS-dGPS Regiocodering Release 4 Release 5 Release 99 RFC RF ID RIPE RIR RLAN Roaming Röntgen straling Rootkit RRC06 RS232 RSPG RSS R&TTE Ruimtegolf