List of abbreviations: R

RA (Working Group) Radio Regulations (ECC)
RA Radiocommunication Assembly (ITU)
RA Radio Astronomy Service (ITU)
RADAR Radio Detecting and Ranging
RAG Radiocommunication Advisory Group (ITU)
RARC Regional Administrative Radio Conference (ITU)
RAS Radio Astronomy Service
RAS Royal Astronomical Society (GB)
RB Radiocommunication Bureau (ITU)
RD Radiodetermination Service
RDS Radiodetermination Service
RDSS Radio Determination Satellite Service
REC Recommendation
 REGTP  Regulatory Authority for Telecommunications and Post (D)
RFI Radio Frequency Interference
RFID Radio Frequency Identification
 RHC  Right Hand Circular
RIN Royal Institute of Navigation (GB)
RIS Radiocommunication Information Systems Department (ITU)
RL Radiolocation Service
R-LAN Radio Local Area Network
 RLS  Radiolocation Service
RN Radionavigation Service
RNS Radionavigation Service
RNSS Radionavigation-Satellite Service
RR ITU-R Radio Regulations (ITU)
RRB Radio Regulations Board (ITU)
 RRC  Regional Radiocommunication Conference (ITU)
RSBN Radiolocation System for Short Range Navigation (Abbreviation stands for the Russian term)
RSC Radio Spectrum Committee (EC)
RSPG  Radio Spectrum Policy Group (EC
 RTAGS Radio Tags
 RTCA  Radio Technical Commission for Aeronautics (USA)
RTT Road Transport Telematics
RTTE Radio and Telecommunications Terminal Equipment (Directive)
RTTT Road Transport & Traffic Telematics