| CPB | Corporation for Public Broadcasting (www.cpb.org) | In English | → Organizations and associations |
| CPL | Courant Porteur en Ligne | In French | → Electrical engineering |
| CPNEF/AV | Commission Paritaire Nationale de l'Emploi et de la Formation dans l'Audiovisuel | In French | → Labour, labour economics → Cinema, movies |
| CPS | Cambridge Positioning System | In English | |
| CPT | Cita Previa Telefónica | In Spanish | |
| ČR | Český Rozhlas (www.rozhlas.cz) | In Czech | |
| CRAL | Coordination des Radios locales Associatives de Lorraine | In French | → Organizations and associations |
| CRC | Cyclic Redundancy Check | In English | → Data → Networks, communication |
| ĈRI | Ĉina Radio Internacia | In Esperanto | |
| CRL | Communication Research Laboratory | In English | → Research institutes |
| CRT | Cathode Ray Tube | In English | → Electronics |
| CRTV | Cameroon Radio and Television (www.crtv.cm) | In English | |
| CS | Communications System | In English | |
| CSA | Conseil Supérieur de l'Audiovisuel | In French | → Organizations and associations → Cinema, movies |
| CSCSAT | Commercial Synchronous Communication Satellite | In English | → Spaceflight engineering, astronautics |
| CSE | Communications Systems Engineer | In English | |
| CSE | Communications Security Establishment = CST | Centre de la Ssécurité des Télécommunications | In French |
In English | |
| CSMA/CD | Carrier Sense Multiple Access with Collision Detection | In English | |
| CSSP | Circuits Systems and Signal Processing | In English | → Serial publications, periodicals |
| CST | Centre de la Ssécurité des Télécommunications = CSE (look above) |
In French | |
| CSTI | Conseil Stratégique des Technologies de l’Information | In French | → Organizations and associations → Computer science |
| ČT | Česká Televize (www.ceskatelevize.cz) | In Czech | |
| CTEU | Centre de Télé-Enseignement Universitaire | In French | → Higher education, universities |
| CTI | Computer Telephony Integration | In English | → Computer science |
| CTI | Couplage Téléphonie Informatique | In French | → Computer science |
| CTIT | Centrum voor Telematica en Informatica Technologie | In Dutch | → Computer science |
| CTM | Cordless Terminal Mobility | In English | |
| CTS | Communications Technology Satellite | In English | → Spaceflight engineering, astronautics |
| CTS | Comprehensive Transponder Systems | In English | |
| CTSB | Community Television of the Southern Berkshires (www.ctsbtv.org) | In English | |
| CUDI | Corporación Universitaria para el Desarrollo de Internet | In Spanish | → Computer science |
| CWDM | Coarse Wavelength Division Multiplexing | In English | → Networks, communication |
| DAB | Digital Audio Broadcasting | In English | |
| DAMA | Demand Assigned Multiple Access | In English | → Spaceflight engineering, astronautics |
| DAP | Décodage Acoustico-Phonétique | In French | → Computer-based techniques → Linguistics |
| DCA | Defense Communication Agency | In English | → Military affairs |
| DCA | Defense Communications Agency | In English | → Military affairs |
| DCE | Data Circuit-terminating Equipment | In English | → Data |
| DDP | Disc Description Protocol | In English | → Cinema, movies |
| DECT | Digital Enhanced Cordless Telecommunication | In English | |
| DECT | Digital Enhanced Cordless Telecommunications | In English | |
| DFA | Deutsche Fernsehnachrichten Agentur (www.dfa.de) | In German | |
| DGT | Direction Générale des Télécommunications | In French | → Central administration |
| DHS | Département Hyperfréquences et Semiconducteurs | In French | → Electronics |
| DIIC | Departamento de Ingeniería de la Información y las Comunicaciones | In Spanish | → Computer science |
| DImTe | Display Imaging Technology | In English | → Serial publications, periodicals |
| DIVX | Digital Video Experience | In English | |
| DMT | Discrete MultiTone Modulation | In English | |
| DMTF | Dual-Tone Multi-Frequency | In English | |
| DORIS | Determination of Orbit Radio Positioning Integrated from Shuttle | In English | → Spaceflight engineering, astronautics |
| DOT | Department of Telecommunications | In English | → Central administration |
| DPCL | Dedicated Payload Communication Link | In English | |
| DPDM | Differential Pulse-Duration Modulation | In English | |
| DR | Danmarks Radio (www.dr.dk) | In Danish | |
| DRF | Digital Radio Frequency | In English | |
| DRS | Data Relay Station | In English | → Data |
| DSC | Dedicated Signal Conditioner | In English | |
| DSCP | Differentiated Services Code Point | In English | → Networks, communication |
| DSI | Direction des Systèmes d'Information | In French | → Computer science |
| DSLAM | Digital Subscriber Line Access Multiplexer | In English | → Networks, communication |
| DSP | Digital Signal Processing | In English | → Computer-based techniques |
| DTA | Digital Terminals & Access | In English | → Human-computer interaction |
| DTE | Digital Television Equipment | In English | |
| DTE | Data Terminal Equipment | In English | → Data |
| DTE | Data Transmission Equipment | In English | → Data |
| DTI | Departement of Trade and Industry | In English | → Trade → Industry, industrial policy |
| DTI | Direction des Transmissions et de l'Informatique | In French | → Computer science |
| DTS | Data Transmission System | In English | → Data |
| DTSL | Data Transfer Systems Laboratory | In English | → Research institutes → Data |
| DTVC | Digital Transmission and Verification Converter | In English | → Computer science |
| DTVC | Data Transmission and Verification Converter | In English | → Data |
| DVB | Digital Video Broadcasting | In English | |
| DVB-C | Digital Video Broadcasting - Cable | In English | |
| DVB-H | Digital Video Broadcasting - Handheld | In English | |
| DVB-S | Digital Video Broadcasting - Satellite | In English | → Spaceflight engineering, astronautics |
| DVB-T | Digital Video Broadcasting - Terrestrial | In English | |
| DVD | Digital Versatile Disc | In English | → Cinema, movies |
| DVIDS | Digital Video and Imagery Distribution System | In English | |
| DVS | Digital Voice System | In English | |
| DWDM | Dense Wavelength Division Multiplexing | In English | → Networks, communication |
| E-MEDINE-MD | Euro-MEditerranean Digital-libraries INtelligent E-learning via Mobile Device | In English | → Libraries → Education |
| E@I | Esperanto ĉe Interreto | In Esperanto | → Networks, communication → Organizations and associations |
| EASI | ETSI (European Telecommunications Standards Institute) Project ATM Services and Inter-operability | In English | |
| EATA | European Association for Telematic Applications | In English | → Associations |
| EBG | Electronic Business Group | In English | → Trade |
| EBOS | E-Business Operating System | In English | → Computer science → Trade |
| EBPP | Electronic Bill Presentment and Payment | In English | → Trade |
| EBU | European Broadcasting Union (www.ebu.ch) = UER | Union Européenne de Radio-télévision | In French = ЕСРТ | Европейски съюз за радио и телевизия | In Bulgarian = ЄТС | Європейський Телерадіомовний Союз | In Ukrainian = ЕВС | Европейский вещательный союз | In Russian = UER | União Europeia de Radiodifusão | In Portuguese |
In English | → Organizations and associations |
| ECCA | European Cable Communications Association | In English | → Associations |
| ECIS | European Conference on Information Systems | In English | → Computer science |
| ECITC | European Committee for IT&T Testing and Certification | In English | → Organizations and associations |
| ECLRv | Electrical Communication Laboratories Review | In English | → Serial publications, periodicals → Electrical engineering |
| ECN | Explicit Congestion Notification | In English | → Networks, communication |
| ECSG | Electronic Commerce Steering Group | In English | → Trade |
| ECTEL | European Telecommunications and Professional Electronics Industry | In English | → Electronics |
| ECTRA | European Committee for Telecommunications Regulatory Affairs | In English | → Organizations and associations |
| EDFA | Erbium Dopped Fiber Amplifier | In English | |
| EDGE | Enhanced Data Rates for GSM Evolution | In English | |
| EDRS | European Data Relay Satellite | In English | → Data → Spaceflight engineering, astronautics |
| EF | Expedited Forwarding | In English | → Networks, communication |
| EFLT | Enhanced Forward Link Trilateration | In English | |
| EFTO | Encrypted For Transmission Only | In English | |
| EFTPOS | Electronic Funds Transfer at Point Of Sale | In English | → Trade |
| EGI | European Grid Initiative | In English | → Networks, communication |
| EGT | Entreprise Générale de Télécommunications | In French | |
| EIC | Experimental Intercom | In English | |
| EICT | European Center for Information and Communication Technologies | In English | → Computer science |
| EIR | Equipment Identity Register | In English | |
| EMAG | ETSI (European Telecommunications Standards Institute) MIS Advisory Group | In English | |
| EMCIT | (Agreement Group for) European Testing of Electromagnetic Compatibility of IT Products | In English | → Quality management → Electronics |
| EMDM | Enhanced Multiplexer/Demultiplexer | In English | → Computer science |
| eMLPP | Enhanced Multi Level Precedence and Preemption | In English | |
| EMS | Enhanced Message Service | In English | |
| EMSP | Enhanced Modular Signal Processor | In English | |
| ENIC | École Nouvelle d'Ingénieurs en Communication | In French | → Specialized or (poly)technical colleges |
| ENSEIRB | École Nationale Supérieure d'Électronique, d'Informatique et de Radiocommunications de Bordeaux | In French | → Specialized or (poly)technical colleges → Electronics → Computer science |
| ENSPT | École Nationale Supérieure des Postes et Télécommunications | In French | → Specialized or (poly)technical colleges → Transport and postal services |
| ENST | École Nationale Supérieure des Télécoms | In French | → Specialized or (poly)technical colleges |
| ENTC | École Nationale de Télécommunications | In French | → Specialized or (poly)technical colleges |
| ENTV | Entreprise Nationale de Télévision (www.entv.dz) | In French | |
| ENUM | Electronic Numbering Protocol | In English | |
| ENVS | Edge Network Video Servers | In English | |
| EONS | Enhanced Operator Name String | In English | |
| EOTD | Enhanced Observed Time Difference | In English | |
| EPIC | European Project on Information Infrastructure Co-ordination Group | In English | |
| EPIISG | European Project on Information Infrastructure Starter Group | In English | |
| ERIS@ | European Regional Information Society Association | In English | → Computer science → Associations |
| ERISA | European Regional Information Society Association | In English | → Networks, communication → Associations |
| ERIT | Établissement de la Radiodiffusion-Télévision Tunisienne | In French | |
| ERO | European Radiocommunications Office (www.ero.dk) | In English | |
| ERR | Eesti Rahvusringhääling | In Estonian | |
| ERT | Ellinikí Radiofonía Tileórasi (www.ert.gr) = ΕΡΤ | Ελληνική Ραδιοφωνία Τηλεόραση | In Greek |
In Greek | |
| ERTU | Egyptian Radio and Television Union | In English | |
| ESG | Electronic Service Guide | In English | |
| ESPRIT | European Strategic Program for Research and Development in IT | In English | → Computer science |
| ESPTT | École Supérieure des Postes et des Télécommunications de Tunis | In French | → Specialized or (poly)technical colleges |
| ESTEM | École Supérieure en Ingénierie de l'Information, Télécommunications et Management (www.estem.ma) | In French | → Specialized or (poly)technical colleges → Computer science → Management |
| ETC | Electronic Toll Collection | In English | → Computer-based techniques |
| ETEBAC | Échanges Télématiques Banque/Client | In French | → Computer science → Banks |
| ETO | European Telecommunications Office (www.eto.dk) | In English | |
| ETRI | Electronics and Telecommunications Research Institute | In English | → Electronics |
| ETS | European Telecommunications Standard | In English | → Standardization |
| ETSETB | Escola Tècnica Superior d’Enginyeria de Telecomunicació de Barcelona (www.etsetb.upc.es) | In Spanish | → Specialized or (poly)technical colleges |
| ETSI | European Telecommunications Standards Institute | In English | → Organizations and associations → Standardization |
| ETTRT | European Transactions Telecommunications Related Technologies | In English | → Serial publications, periodicals |
| EUROCOMSAT | European Consortium Communications Satellite | In English | → Spaceflight engineering, astronautics |
| EUTELSAT | European Telecommunications Satellite Organization | In English | → Organizations and associations → Spaceflight engineering, astronautics |
| EVC | Extravehicular Communications | In English | → Spaceflight engineering, astronautics |
| EVDO | Evolution Data Optimized | In English | |
| EVSTC | Extravehicular Suit Telecommunications | In English | → Spaceflight engineering, astronautics |
| FACC | Ford Aerospace and Communications Corporation | In English | → Spaceflight engineering, astronautics |
| FAR | Fédération des Radios Associatives de la Réunion | In French | → Organizations and associations |
| FARA | Fédération Alsacienne des Radios Associatives | In French | → Organizations and associations |
| FCC | Federal Communications Commission | In English | → Organizations and associations |
| FCR | France Câble Radio | In French | |
| FCS | Federal Communications System | In English | |
| FCyT | Federación de Comunicación y Transporte | In Spanish | → Organizations and associations → Labour, labour economics → Transport and postal services |
| FDMA | Frequency Division Multiple Access | In English | |
| FDT | Full-Duplex Teletype | In English | |
| FEC | Forward Error Correction | In English | |
| FEITIS | Fédération Européenne des Industries Techniques de l'Image et du Son | In French | → Organizations and associations → Cinema, movies |
| FEXT | Far End CrossTalk | In English | |
| FFRC | Fédération Française des Radios Chrétiennes | In French | → Organizations and associations → Christianity |
| FIEEC | Fédération des Industries Électriques, Électroniques et de Communication (www.fieec.fr) | In French | → Organizations and associations → Electrical engineering → Electronics |
| FIEN | Filière des Industries Électroniques et Numériques | In French | → Computer science |
| FiIO | Fiber and Integrated Optics | In English | → Serial publications, periodicals → Optics |
| FIOpt | Fiber Integrated Optics | In English | → Serial publications, periodicals → Optics |
| FISTEL | Federazione Informazione Spettacolo e Telecomunicazioni | In Italian | → Organizations and associations → Entertainment |
| FKTG | Fernseh- und Kinotechnische Gesellschaft (www.fktg.de) | In German | → Organizations and associations → Cinema, movies |
| FM | Frequency Modulated | In English | |
| FM | Frequency Modulation | In English | |
| FM/CW | Frequency-Modulated Continuous Wave | In English | |
| FM/FM | Frequency Modulation/Frequency & Multiplexing | In English | |
| FM/PM | Frequency Modulation/Phase Modulation | In English | |
| FMK | Forum Mobilkommunikation | In German | → Organizations and associations |
| FMSP | Frequency Modulation Signal Processor | In English | |
| FMX | Frequency Modulation Transmitter | In English | |
| FNT | Failure Notification Telex | In English | |
| FO | Fiber-Optic | In English | |
| FODS | Fiber-Optic Demonstration System | In English | |
| FOG | Fiber-Optic Gyro | In English | |
| FOGM | Fiber-Optic Guided Missile | In English | → Military engineering |
| FOIRL | Fiber-Optic Inter-Repeater Link | In English | |
| FRALA | Fédération des Radios Associatives Limousin Auvergne | In French | → Organizations and associations |
| FRAMA | Fédération des Radios Associatives Maine - Anjou | In French | → Organizations and associations |
| FRANC-LR | Fédération des Radios Associatives Non Commerciales Languedoc Roussillon | In French | → Organizations and associations |
| FRANC-MP | Fédération des Radios Associatives Non Commerciales Midi Pyrénées | In French | → Organizations and associations |
| FRANC-RA | Fédération des Radios Associatives Non Commerciales Rhône-Alpes | In French | → Organizations and associations |
| FRANF | Fédération des Radios Associatives du Nord de la France | In French | → Organizations and associations |
| FRC | Fixed Radio Control | In English | |
| FREMP | Fédération Régionale des Entreprises de Multimédia de Midi-Pyrénées | In French | → Organizations and associations → Graphic industries, printing, publishing |
| FRTC | Fédération des Radios et Télévisions Chrétiennes | In French | → Organizations and associations → Christianity |
| FSE | Fast Software Encryption | In English | → Software → Mathematics |
| FSER | Fonds de Soutien à l'Expression Radiophonique | In French | → Public finance |
| FSTS | Frequency Standard Test Set | In English | |
| FSU | Frequency Synthesizer Unit | In English | |
| FTI | Forum per la Tecnologia della Informazione | In Italian | → Organizations and associations → Computer science |
| FTI | Film and Television Institute | In English | → Cinema, movies |
| FTMK | Fakulti Teknologi Maklumat dan Komunikasi | In Malay | → Higher education, universities → Computer science |
| FTS | Federal Telecommunications System | In English |
|