| MR | Magyar Rádió | In Hungarian | |
| MRBT | Maintenance Réseaux-Bureautique-Télématique | In French | → Computer science |
| MRT | Macedonian Radio-Television (www.mkrtv.com.mk) = МРТ | Македонска радио-телевизија | In Macedonian = KVV | Kevarzhe Vannielouriezh Vreizh | In Breton = SBV | Société Bretonne de Vexillologie | In French |
In English | |
| MS | Mobile Station | In English | |
| MSC | Mobile Service Switching Center | In English | |
| MSG | Mobile Standards Group | In English | → Standardization |
| MSISDN | Mobile Station ISDN Number | In English | |
| MT | Mobile Terminal | In English | |
| MTA | Multimedia Terminals & Applications | In English | |
| mTLD | mobile Top Level Domain | In English | → Networks, communication |
| MUSIC | Multiple Signal Classification | In English | → Networks, communication |
| MWC | Mobile World Congress | In English | → Congresses |
| NAATA | National Asian American Telecommunications Association | In English | → Associations |
| NABA | North American Broadcasters Association (www.nabanet.com) | In English | → Associations |
| NASCOM | NASA Communications | In English | → Spaceflight engineering, astronautics |
| NB | Narrow Band | In English | |
| NBA | Narrow-Band Amplifier | In English | |
| NBMA | Nonbroadcast Multiple Access Network | In English | → Networks, communication |
| NDGPS | Nationwide Differential Global Positioning System | In English | → Geodesy, cartography → Spaceflight engineering, astronautics |
| NDR | Norddeutscher Rundfunk | In German | |
| NET | Norme Européenne de Télécommunication(s) | In English | → Standardization |
| NETCOM | Network Communications | In English | |
| NEXT | Near End CrossTalk | In English | |
| NGFAW | Nachrichtentechnische Gesellschaft Fachtagung über Antennen | In German | → Serial publications, periodicals |
| NIR | (Belgisch) Nationaal Instituut voor Radio-omroep | In Dutch | |
| NITZ | Network Identity Time Zone | In English | |
| NOA | National Outsourcing Association | In English | → Associations |
| NPO | Nederlandse Publieke Omroep (www.omroep.nl) | In Dutch | |
| NRA | Nœud de Raccordement Abonné | In French | |
| NRK | Norsk Rikskringkasting (www.nrk.no) | In Norwegian | |
| NRN | National Radio Network | In English | |
| NRU | Natsionalna Radiokompanya Ukraïny | In Ukrainian | |
| NTA | National Television Awards | In English | |
| NTA | National Telecom Agency | In English | |
| NTSC | National Television Standards Committee | In English | → Organizations and associations |
| NTT | Nippon Telegraph and Telephone (www.ntt.co.jp) | In English | |
| NTU | Natsionalna Telekompaniya Ukraïny (www.ntu.com.ua) = UNCITRAL | United Nations Commission on International Trade Law | In English = CNUDCI | Commission des Nations Unies pour le Droit Commercial International | In French = ЮНСИТРАЛ | Комиссия Организации Объединенных Наций по праву международной торговли | In Russian = CNUDMI | Comisión de las Naciones Unidas para el Derecho Mercantil Internacional | In Spanish = НТУ | Національна Телекомпанія України | In Ukrainian |
In Ukrainian | |
| NUCT | Nuova Università del Cinema e della Televisione (www.nuct.com) | In Italian | → Higher education, universities → Cinema, movies |
| OFDM | Orthogonal Frequency Division Multiplexing | In English | → Networks, communication |
| ÖIAT | Österreichisches Institut für angewandte Telekommunikation | In German | → Research institutes |
| OIS | Operational Intercommunication System | In English | |
| OLT | Optical Line Terminal | In English | |
| OMCS | Operations and Maintenance Communications System | In English | → Maintenance and logistics |
| ONT | Optical Network Terminal | In English | → Networks, communication |
| OPPTIC | Organisation de Professionnels pour la Promotion des TIC en région Languedoc-Roussillon | In French | → Networks, communication → Organizations and associations |
| OPSIS | Observation et Prospective sur la Société de l'Information et ses Services | In French | → Computer science |
| OptCo | Optics Communications | In English | → Serial publications, periodicals → Optics |
| OptFT | Optical Fiber Technology | In English | → Serial publications, periodicals → Optics |
| ORF | Österreichischer Rundfunk | In German | |
| ORF | Österreichische Rundfunk (http://orf.at) | In German | |
| ORS | Österreichische Rundfunksender (www.ors.at) | In German | |
| ORTA | Organisme de Ràdio i Televisió d’Andorra | In Catalan | |
| ORTAS | Organisme de la Radio-Télévision Arabe Syrienne | In French | |
| OSCAR | Orbiting Satellite Carrying Amateur Radio | In English | → Spaceflight engineering, astronautics |
| OTV | Operational Television | In English | |
| OVCO | Operational Voice Communication Office | In English | |
| OWF | Optimum Working Frequency | In English | |
| OXCs | Optical cross connects | In English | |
| P&T | Post en Telegraaf | In Dutch | → Transport and postal services |
| P3P | Platform for Privacy Preferences | In English | → Networks, communication |
| PAL | Phase Alternated Line | In English | |
| PB | Point de Branchement | In French | |
| PBB | Provider Backbone Bridge | In English | → Networks, communication |
| PBB-TE | Provider Backbone Bridge - Traffic Engineering | In English | → Networks, communication |
| PBBN | Provider Backbone Bridge Network | In English | → Networks, communication |
| PBEB | Provider Backbone Edge Bridge | In English | → Networks, communication |
| PBS | Public Broadcasting Service | In English | |
| PBT | Provider Backbone Transport | In English | → Networks, communication |
| PBX | Private Branch Exchange | In English | |
| PCI | Peripheral Component Interconnect | In English | → Hardware |
| PCMR | Probability of Correct Message Receipt | In English | |
| PDA | Personal Digital Assistant | In English | → Hardware |
| PDH | Plesiochronous Digital Hierarchy | In English | → Networks, communication |
| PDZ | Point de Distribution de Zone | In French | |
| PET | Persona-Enabling Toolkit | In English | → Networks, communication |
| PFM | Pulse Frequency Modulation | In English | |
| PFN | Pulse Forming Network | In English | |
| PG | Parental Guidance | In English | → Cinema, movies |
| PHB | Per Hop Behavior | In English | → Networks, communication |
| PLC | Power Line Communication | In English | → Electrical engineering |
| PLMN | Public Land Mobile Network | In English | |
| PLSP | Payload Signal Processor | In English | |
| PLT | Powerline Telecommunications | In English | |
| PM | Phase Modulation | In English | |
| PMN | Private Mobile Networks | In English | |
| POTS | Plain Old Telephone Service | In English | |
| PPLMN | Periodic Public Land Mobile Network | In English | |
| PRF | Pulse Repetition Frequency | In English | |
| PRI | Primary Rate Interface | In English | |
| PRI | Point de Raccordement Immeuble | In French | |
| PRISM | Pacific Regional Information SysteM | In English | → Computer science |
| PRR | Pulse Repetition Rate | In English | |
| PSCN | Program Support Communications Network | In English | → Networks, communication |
| PSDU | Power and Signal Distribution Unit | In English | → Energy economics → Electrical engineering |
| PSIU | Power and Signal Interface Unit | In English | → Energy economics → Electrical engineering |
| PSP | Programmable Signal Processor | In English | → Software |
| PSP | Payload Signal Processor | In English | |
| PSTN | Public Switched Telephone Network = RTCP | Réseau Téléphonique Commuté Public | In French = ТСОП | елефонная сеть общего пользования | In Russian |
In English | |
| PT | Post- og Teletilsynet | In Norwegian | → Transport and postal services |
| PTC | Радио-телевизија Србије (www.rts.co.yu) = RTS | Radio Televizija Srbije | In Serbian |
In Serbian | |
| PTCR | Pad Terminal Connection Room | In English | |
| PTN | Publika telefonnätet | In Swedish | |
| PTT | Post Telegraaf Telefoon | In Dutch | → Transport and postal services |
| PTT | Poŝto, Telegrafo kaj Telefono | In Esperanto | → Transport and postal services |
| PVC | Permanent Virtual Circuit | In English | |
| QAM | Quadrature Amplitude Modulation | In English | |
| R&CC | Recorder and Communication Control | In English | |
| RAAP | Red Académica Peruana | In Spanish | → Computer science → Higher education, universities |
| RABF | Radio Astronomy Bandstop Filter | In English | → Astronomy |
| RACC | Radio Advertising Clearance Centre | In English | → 659 |
| RADAR | RAdio Detection And Ranging | In English | |
| RADIUS | Remote Authentication Dial In User Service | In English | |
| RaEE | Radio and Electronic Engineer | In English | → Serial publications, periodicals → Electronics |
| RAGIE | Red Avanzada Guatemalteca para la Investigación y Educación | In Spanish | → Computer science → Education → Mathematics and natural sciences |
| RAI | Radio Audizioni Italiane | In Italian | |
| RAI | Radiotelevisione Italiana | In Italian | |
| RAICES | Red Avanzada de Investigación, Ciencia y Educación Salvadoreña | In Spanish | → Computer science → Education → Mathematics and natural sciences |
| RaRLJ | Radio Research Laboratories Journal | In English | → Serial publications, periodicals |
| RaRLR | Radio Research Laboratories Review | In English | → Serial publications, periodicals |
| RaSc | Radio Science | In English | → Serial publications, periodicals |
| RaScB | Radio Science Bulletin | In English | → Serial publications, periodicals |
| RaScS | Radio Science Supplement | In English | → Serial publications, periodicals |
| RAU | Red Académica Uruguaya | In Spanish | → Computer science → Higher education, universities |
| RBB | Rundfunk Berlin-Brandenburg | In German | |
| RCA | Radio Corporation of America | In English | |
| RCCP | Recorder and Communications Control Panel | In English | |
| RCF | Radios Chrétiennes en France | In French | → Organizations and associations → Christianity |
| RCN | Rockwell Communication Network | In English | |
| RCO | Radio Comptoir de l'Ouest (www.rco.fr) | In French | → Electronics |
| RCSO-TIC | Réseau de Compétences de Suisse Occidentale en Technologie de l'Information et de la Communication | In French | → Computer science |
| RDF | Radio Direction Finding | In English | |
| RDF | Radio Direction Finder | In English | |
| RDO | Radio Dom Ostankino | In Russian | |
| REACCIUN | Red Académica de Centros de Investigación y Universidades Nacionales | In Spanish | → Computer science → Education |
| RedCYT | Red Científica y Tecnológica | In Spanish | → Computer science → Mathematics and natural sciences → Applied sciences, technology |
| REEP | Radio Engineering and Electronic Physics | In English | → Serial publications, periodicals → Electronics |
| RENATA | Red Nacional Académica de Tecnología Avanzada | In Spanish | → Computer science |
| RENIA | Red Nicaragüense de Internet Avanzada | In Spanish | → Computer science |
| RETINA | Red TeleInformática Académica | In Spanish | → Computer science |
| REUNA | Red Universitaria Nacional | In Spanish | → Computer science → Higher education, universities |
| RF | Radio Frequency | In English | |
| RFDA | Radio Frequency Deployed Assembly | In English | |
| RFDU | Radio Frequency and Digital Unit | In English | → Computer science |
| RFI | Radio Frequency Interference | In English | |
| RFI | Radio France International | In French | |
| RFID | Radio Frequency Identification | In English | → Computer science |
| RFTK | Radio Frequency Tracking | In English | |
| RFTS | Radio Frequency Transmission System | In English | |
| RFU | Radio Frequency Unit | In English | |
| RIAM | Réseau d'Innovation Audiovisuel et Multimédia | In French | |
| RICC | Remote Intercomputer Communications | In English | → Networks, communication |
| RIK | Radiofoniko Idryma Kyprou (www.cybc.com.cy) = CBC | Cyprus Broadcasting Corporation | In English = ΡIK | Ραδιοφωνικό Ίδρυμα Κύπρου | In Greek |
In Greek | |
| RNA | Ràdio Nacional d'Andorra | In Catalan | |
| RNC | Radio Network Controller | In English | |
| RNIS | Réseau Numérique à Intégration de Services | In French | |
| RNP | Rede Nacional de Ensino e Pesquisa | In Portuguese | → Computer science |
| RNRS | Entreprise Nationale de Radiodiffusion Sonore (www.algerian-radio.dz) | In French | |
| RNRT | Réseau National de la Recherche en Télécommunications | In French | → Organizations and associations |
| RNRT | Réseau National de Recherche en Télécommunications | In French | → Organizations and associations |
| RPC | Remote Procedure Call | In English | |
| RRA | Rockland Repeater Association (www.rra.net) | In English | → 06126 |
| RS-232 | Recommended Standard 232 | In English | → Standardization |
| RSCIE | Remote Station Communication Interface Equipment | In English | |
| RSI | Radio Slovaquie Internationale (www.slovakradio.sk/inetportal/rsi/) | In French | |
| RSI | Rádio Slovakia International (www.slovakradio.sk/inetportal/rsi/) | In English | |
| RSN | Robust Security Network | In English | → Networks, communication |
| RSTP | Rapid Spanning Tree Protocol | In English | → Networks, communication |
| RSW | RFID, Sensors and Wireless | In English | → Electronics |
| RT | Railway Telecommunications | In English | → Transport and postal services |
| RT/LO | Receiver Transmitter/Local Oscillator | In English | |
| RTA | Radioteknika Artikolaro | In Esperanto | |
| RTB | Red Telefónica Básica | In Spanish | |
| RTB | Radio Television Belgrade | In English | |
| RTBF | Radio-Télévision Belge de la Communauté Française (www.btrc.gov.bd) | In English | |
| RTBF | Radio-Television Belge de la communaute Francaise | In French | |
| RTC | Red Telefónica Conmutada | In Spanish | |
| RTC | Réseau Téléphonique Commuté | In French | |
| RTCA | Radio Technical Commission for Aeronautics | In English | → Organizations and associations → Aeronautics, aircraft |
| RTCP | Réseau Téléphonique Commuté Public = PSTN, ТСОП (look above) |
In French | |
| RTCP | Real-Time Communications Processor | In English | → Hardware |
| RTÉ | Radio Telefís Éireann (www.rte.ie) | In Irish | |
| RTGC | Радио Телевизија Црне Горе (www.rtcg.org) = RTGC | Radio-televizija Crne Gore | In Serbian = CAHV | Croatian Association for Heraldry and Vexillology | In English = HDZG | Hrvatsko Društvo za Zastave i Grbove | In Croatian |
In Serbian | |
| RTGC | Radio-televizija Crne Gore (www.rtcg.org) = CAHV, HDZG (look above) |
In Serbian | |
| RTLM | Radio Télévision Libre des Mille Collines | In French | |
| RTM | Réseaux, Télécoms et Multimedia | In French | → Networks, communication → Document processing |
| RTP | Rádio e Televisão de Portugal (www.rtp.pt) | In Portuguese | |
| RTR | Rossijskoe Teleradio (www.rtr-planeta.com) | In Russian | |
| RTS | Radio Televizija Srbije (www.rts.co.yu) = PTC (look above) |
In Serbian | |
| RTSH | Radio Televizioni Shqiptar (www.rtsh.al) | In Albanian | |
| RTT | Revista Transporturilor şi Telecomunicaţiilor | In Romanian | → Serial publications, periodicals → Transport and postal services |
| RTTV | Real-Time Television | In English | |
| RTVA | Ràdio i Televisió d'Andorra (www.rtvasa.ad) | In Catalan | |
| RTVE | Radiotelevisión Española (www.rtve.es) | In Spanish | |
| RTVSLO | Radiotelevizija Slovenija (www.rtvslo.si) | In Slovenian | |
| RUIM | Removable User Identity Module | In English | |
| RÚV | Ríkisútvarpið (www.ruv.is) | In Icelandic | |
| RV | Radio Vaticana (www.radiovaticana.org) | In Latin | |
| RvTS | Rivista Tecnica Selenia | In Italian | → Serial publications, periodicals |
| S3IT | Schéma Stratégique des Systèmes d'Information et des Télécommunications | In French | → Computer science |
| SACT | Scrittori Associati di Cinema e Televisione Italiani (www.sact.it) | In Italian | → Organizations and associations → Cinema, movies |