List of acronyms and initialisms: C

This list contains acronyms, initialisms, and pseudo-blends that begin with the letter C.

For the purposes of this list:

• acronym = an abbreviation pronounced as a series of constituent letters, e.g., SARS = severe acute respiratory syndrome
• initialism = an abbreviation pronounced wholly or partly using the names of its constituent letters, e.g., CD = compact disc
• pseudo-blend = an abbreviation whose extra or omitted letters means that it cannot stand as a true acronym, initialism, or portmanteau (a word formed by combining two or more words).

(a) = acronym in the example: SARS – (a) Severe acute respiratory syndrome

(i) = initialism in the example: CD – (i) Compact disc

(p) = pseudo-blend in the example: UNIFEM – (p) United Nations Development Fund for Women

(s) = symbol (none of the above, representing and pronounced as something else; for example: MHz – Megahertz)

(Main list of acronyms and initialisms)

• c – (s) Centi
• C – (s) Carbon – Coulomb – One Hundred (in Roman numerals)

C0–9

• C2 or C² – (i) Command and Control
• c2c – (s) the British rail company formerly known as LTS Rail
• C2C – (p) Consumer-To-Consumer electronic commerce – Cam-To-Cam internet chat
• C2D or C²D – (i) Intel Core 2 Duo – CERDEC Command and Control Directorate
• C2IEDM or C²IEDM – (i) Command and Control Information Exchange Data Model
• C2IS or C²IS – (i) Command and Control Information System
• C2PC or C²PC – (i) Command and Control Personal Computer
• C2V or C²V – (i) Command and Control Vehicle
• C2W or C²W – (i) Command and Control Warfare
• C3 or C³ – (i) Colorectal Cancer Condition – Command, Control, and Communications
• C3I or C³I – (i) Command, Control, Communications, and Intelligence
• C4 or C⁴ – (i) Command, Control, Communications, and Computers
• C4I or C⁴I – (i) Command, Control, Communications, Computers, and Intelligence
• C4ISR or C⁴ISR – (i) Command, Control, Communications, Computers, Intelligence, Surveillance and Reconnaissance

CA

• ca – (s) Catalan language (ISO 639-1 code)
• Ca – (s) Calcium
• CA
  • (s) California (postal symbol)
  • Canada (FIPS 10-4 country code; ISO 3166 digram)
  • Catalonia
  • (i) Civil Affairs
  • Close Armour
  • Cocaine Anonymous
  • Computer Associates
  • Counter-Air
  • Cricket Australia
• CAA
  • (i) Canadian Automobile Association
  • (NORAD) Center for Aerospace Analysis
  • (U.S.) Center for Army Analysis
  • (U.S.) Clean Air Act
  • (U.S. Army) Concepts Analysis Agency
  • Civil Aviation Authority
  • Colonial Athletic Association
• CAAT
  • (i) or (a) Campaign Against Arms Trade
  • Center for Alternatives to Animal Testing
• CAC
  • (i) California Association of Criminalists
  • Chronic Asymptomatic [Disease] Carrier
• CACM (i) Central American Common Market
• CACM – (i) Communications of the ACM
• CAD
  • (s) Canadian dollar (ISO 4217 currency code)
  • (a) Computer-Aided Design
  • Computer-Aided Dispatch
• CADCAM – (a) Computer-Aided Design/Computer-Aided Manufacturing
• CADPAT – (p) CAnadian Disruptive PATtern
• CADMID – (a) Concept, Assessment, Demonstration, Manufacture, In service, Disposal (life cycle mnemonic)
• CAE
  • (i) Canadian Aviation Electronics (originally)
  • Certificate in Advanced English
• CAEn – (i/a) Close Action Engagement (constructive simulation)
• CAF
  • (s) Central African Republic (ISO 3166 trigram)
  • (i) Confederation of African Football (or French Confédération Africaine de Football)
• CAFAD – (a) Combined Arms For Air Defence
• CAFDE
  • (a) Canadian Association of Film Distributors and Exporters
  • Computer Aided Federation Development Environment
• CAFE – (a) Corporate Average Fuel Economy standard
• CAI – (i) Computer Assisted Instruction
• CAIR – (i) Council on American-Islamic Relations
• CALABARZON – (p) A region in the Philippines: CAvite, LAguna, BAtangas, Rizal, queZON
• CALL – (a) (U.S.) Center for Army Lessons Learned
• CALM – (p) Communications, Air-interface, Long and Medium range
• CalPERS – (p) California Public Employees' Retirement System
• Caltrans – (p) California Department of Transpotation
• CAM
  • (a) Chemical Agent Monitor
  • Complementary and alternative medicine
  • Computer-Aided Manufacturing
  • Crassulacean acid metabolism (type of photosynthesis)
• CAMRA – (p) CAMpaign for Real Ale
• CAN – (s) Canada (ISO 3166 trigram)
• CANA – (a) Convulsive Antidote, Nerve Agent
• CANDU – (p) CANada Deuterium Uranium (nuclear reactor design)
• Canola – (p) Canadian oil, low acid (referring to a specific cultivar of rapeseed bred to have a low erucic acid content)
• CAP
  • (i) Combat Air Patrol
  • Civil Air Patrol
  • Common [Operating/Operational] Air Picture
  • Crisis Action Procedures
  • Common Agricultural Policy (European Union)
• CAPES
  • (p) CAPability Evaluation System
  • (a) Combined Arms Planning and Execution System
• CARE
  • (a) Citizens Association for Racial Equality (former New Zealand organisation)
  • (p) Community database on Accidents on the Roads in Europe
  • (a) Cooperative for Aid and Relief Everywhere (originally Cooperative for American Remittances to Europe)
• CARMONETTE – (p) Computerized Monte Carlo Simulation
• CARP – (a) Computed Air Release Point
• CART – (a) Championship Auto Racing Teams (now defunct)
• CAS
  • (i) Chemical Abstracts Service
  • Chief of the Air Staff
  • Close Air Support
• CASE
  • (a) Cellular ammunition storage equipment
  • Computer-Aided Software Engineering
• CASS – (a) Command Activated Sonobuoy System
• CASTFOREM – (p) Combined Arms and Support Task FORce Evaluation Model
• CASTOR – (a) Canadian Automatic Small Telescopes for Orbital Research
• cat – (s) Catalan language (ISO 639-2 code)
• CAT
  • (a) Community Acceptance Testing
  • Computer-Assisted (or Axial) Tomography
• CATK – (p) Counterattack
• CATS – (a) Computer Active Technology Suspension
• CATT – (a/i) Combined Arms Tactical Trainer
• CAV – (p) Cavalry
• CAVOK – (p) Ceiling And Visibility OK ("Kav-okay")
• CAW – (i) Canadian Auto Workers (trade union)

CB

• CB
  • (i) Citizens' Band radio
  • (s) Cambodia (FIPS 10-4 country code)
• CBASSE – (a) Commission on Behavioral And Social Sciences and Education ("sea bass")
• CBC
  • (i) Canadian Broadcasting Corporation
  • Christmas Bird Count
  • Cipher-Block Chaining
  • Cornering Brake Control
• CBE
  • (i) Commander of the Order of the British Empire
  • Cab Beside Engine (see truck)
• CBF – (i) Confederação Brasileira de Futebol (Portuguese, "Brazilian Football Confederation")
• CBGB – (i) Country, Blue Grass, and Blues (former New York City nightclub)
• CBLA – (i) Comparative bullet lead analysis
• CBM – many, including Canadian Baptist Ministries and Commodore Business Machines; see entry
• CBML – (i) Coalition Battle Management Language
• CBOL – (i) Consortium for the Barcode of Life
• CBOT – (i) Chicago Board of Trade
• CBR – (i) Case-Based Reasoning
• CBRN – (i) Chemical, Biological, Radiological, or Nuclear (weapon or event)
• CBRNE – (i) Chemical, Biological, Radiological, Nuclear or [high-yield] Explosive (weapon or event)
• CBS
  • (i) Columbia Broadcasting System
  • Corps Battle Simulation
• CBT
  • (i) Cognitive Behaviour Therapy
  • (p) Combat
• CBUS – (i) Columbus, Ohio

CC

• CC – many, including carbon copy; see entry
• CCA – (i) Counter Command Activity
• CCC
  • (i) Canterbury Clothing Company
  • Civilian Conservation Corps (U.S., 1930s and 1940s)
  • Corpus Christi College, Oxford
• CCCP
  • (i) Central Committee of the Communist Party
  • Cyrillic for SSSR (Soyuz Sovetskikh Sotsialisticheskikh Respublik, Russian Союз Советских Социалистических Республик, Union of Soviet Socialist Republics)
• CCD
  • (i) Charge-Coupled Device
  • Confraternity of Christian Doctrine (Catechism)
• CCF – (i) Cartoon Cartoon Fridays
• CCG
  • (i) Canadian Coast Guard
  • Collectible Card Game
• CCGC
  • (i) Canadian Coast Guard Cutter
  • Canadian Coast Guard College
• CCGH – (i) Canadian Coast Guard Hovercraft
• CCGS
  • (i) Canadian Coast Guard Ship
  • Christ Church Grammar School
• CCH – (i) Computer-Controlled Hostile
• CCIF – (p) Comité consultatif international des communications téléphoniques à grande distance (French for International Telephone Consultative Committee, merged with the CCIT in 1956 to form the CCITT)
• CCII
  • (i) Command and Control Information Infrastructure
  • Community Capital Investment Initiative
• CCIR
  • (i) Comité consultatif international pour la radio (French for Consultative Committee on International Radio, became the ITU Radiocommunication Sector, ITU-R, in 1992)
  • Commander's Critical Information Requirements
• CCIT – (p) Comité consultatif international télégraphique (French for International Telegraph Consultative Committee, merged with the CCIF in 1956 to form the CCITT)
• CCITT – (p) Comité consultatif international téléphonique et télégraphique (French for International Telegraph and Telephone Consultative Committee, became the ITU Telecommunication Standardization Sector, ITU-T, in 1992)
• CCK
  • (p) Cholecystokinin
  • (s) Cocos (Keeling) Islands (ISO 3166 trigram)
• CCM
  • (i) Canada Cycle & Motor Co. Ltd. (now split into two separate companies bearing the CCM name, one manufacturing bicycles and the other ice hockey equipment)
  • Contemporary Christian music
• CCOC
  • (i) Canadian Children's Opera Chorus
  • Crosley Car Owners Club
• CCOP – (i) Coalition Common Operating/Operational Picture
• CCP
  • (i) Casualty Collection Point
  • Communications Checkpoint
  • Contingency Communications Package
• CCPA – (i) Consumer Credit Protection Act
• CCR – (i) Creedence Clearwater Revival
• CCRAp – (p) Canadian Conservative Reform Alliance party
• CCRP – (i) Command and Control Research Program
• CCRTS – (i) Command and Control Research and Technology Symposium
• CCSCS – (a) Coordinadora de Centrales Sindicales del Cono Sur
• CCSCS – (i) Consultative Committee for Space Data Systems
• CCSIL – (i) Command and Control Simulation Interface Language ("cecil")
• CCSK – (i) Cyclic Code Shift Keying
• CCT – (i) Current Commitments Team
• CCTT – (i) Close Combat Tactical Trainer

CD

• cd – (s) Candela
• Cd – (s) Cadmium
• CD – many, including Compact Disc; see entry
• CD1 – (i) Cluster of Differentiation 1 (a small gene family)
• CDA – (i) UK Centre for Defence Analysis
• CDC
  • (i) Centers for Disease Control and Prevention (originally (U.S.) Communicable Disease Center)
  • Control Data Corporation
  • Cult of the Dead Cow
• CDD – (i) Capabilities Development Document
• CDE – (i) Chemical Defence Equipment
• CDEC – (i) U.S. Combat Development Experimentation Center
• CDF
  • (i) California Department of Forestry [and Fire Protection]
  • Common Data Format
  • (s) Democratic Republic of Congo franc congolais (ISO 4217 currency code)
• CDIAC – (a) Carbon Dioxide Information Analysis Center ("see-dee-ack")
• CDipAF – (i) Certified Diploma in Accounting and Finance
• CDM
  • (i) Clean Development Mechanism (Kyoto protocol)
  • Cold Dark Matter (astronomy)
• CDMA – (i) Code Division Multiple Access
• CDMSII – (p) Cryogenic Dark Matter Search II
• Cdr – (p) Commander
• CDS
  • (i) Chief of the Defence Staff
  • Credit default swap
• Cdt – (p) Commandant
• CDT – (i) Central Daylight Time (UTC−5 hours)

CE

• ce – (s) Chechen language (ISO 639-1 code)
• Ce – (s) Cerium
• CE – many, including Christian/Common Era (cf. AD); see entry
• CEA – (i) Campaign Effectiveness Analysis
• CECOM – (p) U.S. Army Communications and Electronics Command
• CEDEX – (p) Courrier d'entreprise à distribution exceptionnelle (French, "Company Mail with Exceptional Distribution"; "exceptional" refers to the volume of mail)
• CEGEP – (i) Collège d'enseignement général et professionnel (French, "College of General and Vocational Education")
• CEI – (i) Competitive Enterprise Institute
• CENTCOM – (p) United States Central Command
• CENTO – (a) Central Treaty Organization (Baghdad Pact)
• CENZUB – (p) Centre d'entraînement aux actions en zone urbaine (French, "Urban Operations Training Centre")
• CEO – (i) Chief Executive Officer
• CEP – (i) Circular Error Probable
• CEPT – (a/i) Conférence européenne des administrations des postes et des télécommunications (French, "European Conference of Postal and Telecommunications Administrations")
• CERCLA – (a) U.S. Comprehensive Environmental Response, Compensation, and Liability Act (Superfund)
• CERDEC – U.S. Communications-Electronics Research, Development and Engineering Center
• CERGA – (a) Centre de recherches en géodynamique et astrométrie (French, "Astrometry and Geodynamics Research Centre")
• CERN – (a) Centre européen pour la recherche nucléaire (French, "European Organization for Nuclear Research")
• CERT – (a) Computer Emergency Response Team
• ces – (s) Czech language (ISO 639-2 code)
• CESS – (i) Centre for Earth Science Studies (India)
• CEV – (i) Combat Engineer Vehicle – Crew Exploration Vehicle
• CEWC – (a/i) Council for Education in World Citizenship

CF

• cf. – (i) confer (Latin "compare", or "see also")
• Cf – (s) Californium
• CF – (i) Canadian Forces – (s) Central African Republic (ISO 3166 digram) – Republic of the Congo (FIPS 10-4 country code)
• CFA – (i) Cat Fanciers' Association – Chartered Financial Analyst – Colour Filtering Array – County Fire Authority – Covering Force Area
• CFAR – (i) Christine's – Federal Acquisition Regulation
• CFC – (i) ChloroFluoroCarbon - Canadian Fish Company
• CFES – (a) Continuous Flow Electrophoresis System
• CFFZ – (i) Call For Fire Zone
• CFG – (i) Context-free grammar – Control flow graph
• CFHT – (i) Canada-France-Hawaii Telescope
• CFI – (i) Center for Inquiry (CSICOP)
• CFL – (i) Canadian Football League – Co-ordinated Fire Line
• CFLCC – (i) Coalition Forces Land Component Command
• CFM – (i) Certified Facilities Manager [(IFMA)]http://www.ifma.org/
• CFO – (i) Chief Financial Officer
• CFR – (i) Code of Federal Regulations – Căile Ferate Române (Romanian, "Romanian Railways")
• CFRP – (i) Carbon fibre reinforced plastic
• CFS – (i) Chronic Fatigue Syndrome
• CFSP – (i) Common Foreign and Security Policy
• CFU – (i) Colony Forming Unit(s) in Microbiology
• CFV – (i) Cavalry Fighting Vehicle
• CFZ – (i) Critical Friendly Zone

CG

• CG – (i) Client Group – Computer Graphics – (s) Democratic Republic of the Congo (FIPS 10-4 country code) – Republic of the Congo (ISO 3166 digram)
• CG – (ii) Controls Group
• CGDC – (i) Computer Game Developers Conference (became GDC in 1998)
• CGF – (i) Computer-Generated Forces (Simulation)
• CGH – (i) Comparative Genomic Hybridisation
• CGIG – (i) Cross-Government Implementation Group
• CGM – (i) Computer Graphics Metafile
• CGO – (s) Republic of the Congo (IOC and FIFA trigram, but not ISO 3166)
• CGS – (i) Chief of the General Staff
• CGSI -Consumer Guidance Society of India
• CGT – (i) Capital Gains Tax

CH

• ch – (s) Chamorro language (ISO 639-1 code)
• CH – (p) Chieftain tank – (s) China (FIPS 10-4 country code) – Switzerland (ISO 3166 digram; from Latin Confoederatio Helvetica)
• cha – (s) Chamorro language (ISO 639-2 code)
• CHAMPUS – (a) (U.S.) Civilian Health and Medical Program of the Uniformed Services (now known as TRICARE)
• CHAOS – (a) Cambridge Heart Anti-Oxidant Study
• CHAPS - Clearing House Automated Payment System
• che – (s) Chechen language (ISO 639-2 code)
• CHE – (s) Switzerland (ISO 3166 trigram; from Latin Confoederatio Helvetica)
• CHF – (s) Swiss franc (ISO 4217 currency code)
• CHI – (i) Columbia Helicopters, Inc
• CHI – (i) Computer-Human Interaction
• CHiP – (a) California Highway Patrol
• CHIPS – (a) Cosmic Hot Interstellar Plasma Spectrometer
• CHL – (s) Chile (ISO 3166 trigram)
• CHLA – (a) Core Historical Literature of Agriculture
• CHN – (s) China (ISO 3166 trigram)
• CHOGM – (a) Commonwealth Heads of Government Meeting
• CHP – (i) California Highway Patrol – Combined Heat and Power
• CHS – (i) Combat Health Support
• CHT – (i) Certified Hand Therapist
• chu – (s) Old Church Slavonic language (ISO 639-2 code)
• chv – (s) Chuvash language (ISO 639-2 code)
• CREN – (p) Christian Real Estate Network Real Estate Association

CI

• Ci – (s) Curie
• CI
  • (s) Chile (FIPS 10-4 country code)
  • Côte d'Ivoire (ISO 3166 digram)
  • (i) Counter-Intelligence
  • 101 (in Roman numerals)
• CIA
  • (i) Cairo International Airport
  • Central Intelligence Agency
  • Culinary Institute of America
• CIAO
  • (i) Critical Infrastructure Assurance Office
  • Component-Integrated ACE ORB
• CIB – (i) Complete In Box (Internet auction/trading listings)
• CIBC – (i) Canadian Imperial Bank of Commerce (obsolete)
• CICS – (a) Customer Information Control System (IBM mainframe software; "kicks" or "C-I-C-S")
• CID
  • (p) Combat Identification
  • (i) Criminal Investigation Division
  • Criminal Investigations Department
• CID - Certified Interior Designer - A Certified Interior Designer (CID) licensed in New York (USA) plans, designs, supervises and/or consults on various aspects of interior spaces.
• CIÉ – (i) Commission internationale de l'éclairage
• CIEF – (i) Comité international d'enregistrement des fréquences (International Frequency Registration Board)
• CIF – (i) Cost, Insurance, and Freight (Paid) (shipping)
• CIMIC – (p) Civil-Military Co-operation
• CIMMYT – (a/i) Centro Internacional de Mejoramiento de Maíz Y Trigo (Spanish, "International Maize and Wheat Improvement Center")
• CINC – (p) Commander in Chief
• CINEOS – (a) Campo Imperatore Near-Earth Objects Survey
• CIO
  • (i) Chief information officer
  • Congress of Industrial Organizations
• CIP – (a) Combat Identification Panel
• CIPE – (i) (European) Centre for International Political Economy
• CIR – (i) (Commander's) Critical Information Requirements
• CIR – (s) Corotating Interaction Region
• CIS
  • (i) Canadian Interuniversity Sport
  • Commonwealth of Independent States
  • Command and Information System
  • Communication and Information System
• CISA – (a) (U.S.) C4I Integration Support Activity
• CISB – (i) Complete In Sealed Box (Internet auction/trading listings)
• CISPR – (i) Comité international spécial des perturbations radioélectriques (Special International Committee on Radio Interference)
• CISSP – (i) Certified Information Systems Security Professional
• CITES – (p) Convention on International Trade in Endangered Species (of Wild Fauna and Flora) ("sigh-tease")
• CITS – (i) Combat Identification Training System
• CIV – (s) Côte d'Ivoire (ISO 3166 trigram)
• CIVETS – (a) Colombia, Indonesia, Vietnam, Egypt, Turkey, South Africa (economics)
• CIVPOP – (p) Civilian Population
• CIWS – (i) Close-In Weapon System
• CHRS – Canadian Heart Rhythm Society

CJ

• CJ – (s) Cayman Islands (FIPS 10-4 country code) – (i) Criminal Justice
• CJC – (i) Canadian Jewish Congress – Cold Junction Compensation
• CJD – (i) Chronological Julian Day – Creutzfeldt-Jakob Disease
• CJCS – (i) Chairman of the Joint Chiefs of Staff
• CJO – (i) Chief of Joint Operations
• CJTF – (i) Combined Joint Task Force

CK

• CK – (s) Cocos (Keeling) Islands (FIPS 10-4 country code) – Cook Islands (ISO 3166 digram)
• CKA – (i) commonly known as, (a) Canada Kicks Ass
• CKND – Codename: Kids Next Door

CL

• Cl – (s) Chlorine
• CL – (s) Chile (ISO 3166 digram) – (i) Co-ordination Line – One Hundred and Fifty (in Roman numerals)
• CLA – (i) Clutterers Anonymous
• CLEC – (i) Competitive Local Exchange Carrier
• CLEMARS – (a) California Law Enforcement Mutual Aid Radio System
• CLI – (i) Command Line Interface/Interpreter
• CLIC – (p) Compact LInear Collider
• CLO – (i) Cornell Lab of Ornithology
• CLOB – (p) Character Large OBject
• CLOS – (i) Command to Line-Of-Sight (missile control system)
• CLOS – (a) Common Lisp Object System
• CLP – (s) Chilean peso (ISO 4217 currency code) – (i) Common [Operating/Operational] Land Picture
• CLPFC – (i) CentroLateral PreFrontal Cortex
• CLRP – (a) College Loan Repayment Program

CM

• Cm – (s) Curium
• CM – (s) Cameroon (FIPS 10-4 country code; ISO 3166 digram) – (i) Cruise Missile – (s) Nine Hundred (in Roman numerals)
• CMA – (i) U.S. Chemical Materials Agency – (i) Crystal Meth Anonymous
• CMB – (i) Cosmic Microwave Background
• CMBR – (i) Cosmic Microwave Background Radiation
• CME – (a) Coronal Mass Ejection (usually Sun)
• CMHC – (i) Canada Mortgage and Housing Corporation
• CMIS – (a) Content Management Interoperability Services – (a) Common management information service
• CMJ – (i) Christopher Martin-Jenkins (BBC sports commentator)
• CML – (p) Chemical – (i) Chronic Myelogenous Leukemia (formerly Chronic Myeloid Leukemia)
• CMLL – (i) Consejo Mundial de Lucha Libre (Spanish, "Worldwide Wrestling Council"—Mexican professional wrestling promotion)
• CMM – (i) Capability Maturity Model
• CMMC – (i) Corps Materiel Management Centre
• CMML – (i) Chronic MyeloMonocytic Leukemia, (i) Continuous Media Markup Language
• CMO – (i) Civil-Military Operations
• CMOC – (i) Civil-Military Operations Centre
• CMOS – (i) Canadian Meteorological and Oceanographic Society – Complementary Metal-Oxide-Semiconductor
• CMP – (i) Common [Operating/Operational] Maritime Picture
• CMP – (i) Canadian Military Pattern truck (World War II)
• CMPD – (i) Chronic Myeloproliferative Disease
• CMPD – (i) Charlotte Mecklenburg Police Department
• CMR – (s) Cameroon (ISO 3166 trigram) – (i) Coaxial Main Rotors (helicopter type)
• CMS – (i) Centers for Medicare and Medicaid Services - (a) The Chicago Manual of Style
• CMT – (i) Country Music Television
• CMU – (i) Carnegie Mellon University, (i) Central Michigan University, (i) Concrete Masonry Unit
• CMW – Marconi's Wireless Telegraph Company of Canada – Canadian Manufacturing Week—Canadian Music Week – Catherine McAuley Westmead (school in New South Wales, Australia) – Chicago, Missouri and Western (Railway) – Compartmented Mode Workstation – Compton's Most Wanted – Continuous Microwave (processing technology) – Custom Maintenance Wizard, (Microsoft Office Resource Kit)
• CMYK – (i) Cyan Magenta Yellow Key/blacK (colour model)

CN

• Cn – (i) Canadian National (railway) – (s) China (ISO 3166 digram) – Comoros (FIPS 10-4 country code)
• CNA – (i) Center for Naval Analyses – Certified Network Administrator – Computer Network Attack
• CNBC – (a/i) Consumer News and Business Channel
• CND – (i) Campaign for Nuclear Disarmament – Computer Network Defence
• CNE – (i) Canadian National Exhibition – Computer Network Exploitation – Certified Network Engineer
• CNI – (i) Communications, Navigation and Identification
• CNI – (a) Clinical Nursing Intern
• CNN – (i) Cable News Network – Cellular Nonlinear Network
• CNO – (i) Computer Network Operations
• CNR – (i) Canadian National Railway – Combat Net Radio
• CNV – (i) Copy-Number Variable (genetics)
• CNY – (s) Chinese yuan renminbi (ISO 4217 currency code)

CO

• c/o – (i) care of (postal code indicating temporary address change)
• co – (s) Corsican language (ISO 639-1 code)
• Co – (s) Cobalt
• Co. – Company
• CO – many, including Central Office (phone company); see entry – (s) Colorado (postal symbol) – (i) Commanding Officer (military)
• COA – (i) Certificate/Concept Of Analysis – Course Of Action (military)
• COB – (i) Close Of Business [day]
• COBOL (p) – COmmon Business-Oriented Language
• COCOM – (p) Combatant Command (military)
• COD – (i) Cash On Delivery – (s) Democratic Republic of the Congo (ISO 3166 trigram)
• CoDA – (i) Co-Dependents Anonymous
• codec – (p) Coder-Decoder / Compressor-Decompressor / Compression-Decompression algorithm
• COE – (i) Cab Over Engine (see truck) – Common Operating Environment (military)
• COEA – (i) Cost Operational Effectiveness Analysis (military)
• COEIA – (i) Combined Operational Effectiveness and Investment Appraisal (military)
• C of I – (i) Certificate of Indebtedness (financial) – (i) The College of Idaho
• COFT – (i) Conduct Of Fire Trainer (military)
• COG – (i) Centre Of Gravity – Current Operations Group (military) – (s) Republic of the Congo (ISO 3166 trigram)
• COGENT – (a) Cognitive Objects within a Graphical EnviroNmenT
• COIL – (a) Chemical Oxygen Iodine Laser
• COIN – (p) Counter-Insurgency (military)
• COK – (s) Cook Islands (ISO 3166 trigram)
• COL – (s) Colombia (ISO 3166 trigram)
• COLA – (a) comp.os.linux.announce – Cost Of Living Adjustment
• COLT – (a) Combat Observation and Lasing Team (military)
• COM – (s) Comoros (ISO 3166 trigram) – (a) Component Object Model
• COMECON – (p) Council for Mutual Economic Assistance (economic counterpart of the Warsaw Pact, 1949–1991)
• COMMZ – (p) Communications Zone (military)
• COMSEC – (p) Communications Security (military)
• CONAD – (p) U.S. Continental Air Defense Command
• CONCACAF – (a) Confederation Of North, Central American and Caribbean Association Football
• CONMEBOL – (p) Confederación Sudamericana de Fútbol or Confederação Sul-Americana de Futebol (respectively Spanish and Portuguese for "South American Football Confederation")
• CONOPS – (p) Concept of Operations (military)
• CONUS – (p) Continental United States
• COO – (i) Chief Operating Officer
• COP – (s) Colombian peso (ISO 4217 currency code) – (a) Common Operating/Operational Picture
• COPE – (a) U.K. Committee On Publication Ethics
• COPUS – (p) U.K. Committee on the Public Understanding of Science
• cor – (s) Cornish language (ISO 639-2 code)
• CORBA – (a) Common Object Request Broker Architecture
• CORD – (i/a) Common Operational Requirements Document
• CORE – (a) Consortium for Oceanographic Research and Education
• CORG – (i) (U.S.) Combat Operations Research Group
• COROT – (p) COnvection, ROtation and planetary Transits
• cos – (s) Corsican language (ISO 639-2 code) – Cosine
• COS – (i) Cooper Ornithological Society
• COSCOM – (p) Corps Support Command (military)
• COSER – (p) COoperative SERvice
• COTS – (a) Commercial Off The Shelf
• Coy – (s) Company (military unit)Cow

CP

• CP – (i) Canadian Pacific – Check Point – Command Post - Club Penguin
• CPA – (i) Certified Public Accountant
• CPAC – (p) Conservative Political Action Conference - Cable Public Affairs Channel ("see-pack")
• CPCU – Certified Property Casualty Underwriter
• CPD – (i) Capabilities Production Document
• CPE – (i) Certificate of Proficiency in English
• CPE – (i) Certified Professional Ergonomist
• CPF – (i) Calibration Parameter File – Canadian Patrol Frigate
• CPG – (a) Clinical Practice Guideline
• CPIM – (a) Certification on Production and Inventory Management
• CPON – (i) Certified Pediatric Oncology Nurse
• CPPCC – (i) Chinese People's Political Consultative Conference
• CPR – (i) Canadian Pacific Railway
• CPR – (i) Cardiopulmonary resuscitation
• CPSM – (i) Continuous Phase Shift Modulation
• CPSU – (i) Communist Party of the Soviet Union
• CPT – (i) Contingency Planning Team
• CPU – (i) Central Processing Unit – Contract Postal Unit
• CPV – (s) Cape Verde (ISO 3166 trigram)
• CPX – (p) Command Post eXercise

CQ

• CQ – (i) Carrier Qualification – Central Queensland – Charge of Quarters – Congressional Quarterly – Constellation Airlines (IATA airline designator) – Northern Mariana Islands (FIPS 10-4 territory code)
• CQD – (i) Close Quarters Drill (Morse distress code preceding SOS: CQ "calling all stations", D "Distress"; often incorrectly interpreted as "Come Quick, Distress")

CR

• cr – (s) Cree language (ISO 639-1 code)
• Cr – (s) Chromium
• CR
  • (s) Coral Sea Islands (FIPS 10-4 territory code)
  • Costa Rica (ISO 3166 digram)
• CRAM – (i) Combined Radiometric Correction Model
• CRC
  • (i) Central RTI Component
  • Chemical Rubber Company
  • Christian Reformed Church
  • Control and Reporting Centre
  • Cyclic Redundancy Check
  • (s) Costa Rican colón (ISO 4217 currency code)
  • Costa Rica (IOC and FIFA trigram, but not ISO 3166)
• CRD – (i) Capstone Requirements Document
• cre – (s) Cree language (ISO 639-2 code)
• CREB – (a) Cyclic AMP-response Element Binding (protein)
• CREEP – (a) Committee for the Re-Election of the President, a pejorative nickname used by opponents
• CRI
  • (a) China Radio International
  • (s) Costa Rica (ISO 3166 trigram)
• CRIPL – (i) Consolidated Remain-In-Place List
• CRM – (i) Cardiac Rhythm Management – Customer Relationship Management
• CRO – (s) Croatia (IOC and FIFA trigram, but not ISO 3166)
• CRP
  • (i) Committee for the Re-Election of the President
  • Control and Reporting Post
• CRT
  • (i) Cardiac Resynchronization Therapy
  • Cathode Ray Tube
  • Chinese Remainder Theorem
• CRTC – (i) Canadian Radio-television and Telecommunications Commission

CS

• cs – (s) Czech language (ISO 639-1 code)
• Cs – (s) Caesium
• CS – (i) Combat Support – Computer Scientist – (s) Costa Rica (FIPS 10-4 country code) – Serbia and Montenegro (ISO 3166 digram)
• CSA – (i) Canadian Space Agency – Canadian Standards Association – Child Support Agency – Command Staff Advisor – Community-supported agriculture – Confederate States of America – Corps Storage Area – (p) Czech Airlines
• C/S/A – (i) CINC, Service, and Agency
• CSAR – (p) Combat Search and Rescue ("seessar")
• CSC – (i) Closed Spacelike Curve (relativity) – Computer Security Centre
• CSEAL – (i/a) Combat Systems Engineering and Analysis Laboratory ("see-seal")
• CSERIAC – (p) (U.S. DoD) Crew Systems Ergonomics Information Analysis Center
• CSG – (i) Corps Support Group
• CSI – see entry
• CSICOP – (i) Committee for the Scientific Investigation of Claims of the Paranormal (became the Committee for Skeptical Inquiry in 2006)
• CSIP – (i) Commercial Stable Image Platform (AMD)
• CSIS – (p) Canadian Security Intelligence Service ("seessiss") – (i) (U.S.) Center for Strategic & International Studies
• CSK – (s) Czechoslovakia (ISO 3166 trigram; obsolete since 1993)
• CSL – (i) U.K. Central Science Laboratory
• C-SPAN – (i) Cable-Satellite Public Affairs Network
• CSPI – (i) Center for Science in the Public Interest
• CSR – (i) Control Supply Rate
• CSR – (i) Corporate Social Responsibility [1]
• CSRC – (i) Conflict Studies Research Centre
• CSRF – (i) Cross-Site Request Forgery
• CSS – (i) Cascading Style Sheets – Catalina Sky Survey – Central Security Service – Combat Service Support – Confederate States Ship – Content-scrambling system – Cross-site scripting
• CSSCS – (i) Combat Service Support Control System
• CST – (i) Central Standard Time (UTC−6 hours)

CT

• CT – (i) Computed tomography (medical scan also known as a CAT scan), Central Time zone, (s) Connecticut (postal symbol), Canterbury (postal symbol), (i) Chrono Trigger (Computer/Video games)
• CTA
  • (s) Central African Republic (FIFA trigram, but not ISO 3166 or IOC)
  • (i) Chicago Transit Authority
  • (i) Comando-Geral de Tecnologia Aerospacial (Portuguese, [Brazilian] "General Command for Aerospace Technology")
• CTBT – (i) Comprehensive [Nuclear] Test Ban Treaty
• CTC – (i) Closed Timelike Curve (relativity) – (U.S.) Combat Training Center
• CTDB – (i) Compact Terrain Data Base (file format)
• CTE
  • (s) Canton and Enderbury Islands (ISO 3166 trigram; obsolete 1984)
  • (i) Chronic traumatic encephalopathy
• CTGF – (i) connective tissue growth factor
• CTI – (i) Co-operative Target Identification
• CTIL – (i) Critical Tracked Items List
• CTIS – (i) Central Tire-Inflation System
• CTMS – (i) Clinical Trial Management System
• CTO – (i) Chief Technical Officer – Chief Technology Officer
• CTS – (i) Clear-To-Send – Collective Training Standards – Communications Technology Service – Contract Technical Services – Conversation Time Sharing – COSMIC Top Secret
• CTSS – (i) Compatible Time-Sharing System
• CTU – (i) Counter Terrorist Unit (fictional branch of the Central Intelligence Agency in the television action series 24)
• CTVT – (i) Canine Transmissible Venereal Tumour

CU

• cu – (s) Old Church Slavonic language (ISO 639-1 code)
• Cu – (s) Copper (Latin Cuprum)
• CU – (s) Carrie Underwood – Cuba (FIPS 10-4 country code; ISO 3166 digram)
• CUB – (s) Cuba (ISO 3166 trigram)
• CUCV – (i) Commercial Utility Cargo Vehicle
• CUNY – (a) City University of New York ("CUE-knee")
• CUP – (s) Cuban peso (ISO 4217 currency code)
• CUPE – (a) Canadian Union of Public Employees ("CUE-pee")
• CUPS – (a) Common Unix Printing System
• CUPW – (i) Canadian Union of Postal Workers
• CUREA – (a) Consortium for Undergraduate Research and Education in Astronomy
• CuW – (s) Copper-tungsten pseudo-alloy (from the chemical symbols of the two component elements)
• CUW – (s) Curaçao (ISO 3166 trigram)

CV

• cv – (s) Chuvash language (ISO 639-1 code)
• CV – many, including curriculum vitae (résumé); see entry
• CVCC
  • (i) Combat Vehicle Command and Control
  • Compound Vortex Controlled Combustion (1970s Honda automobile engine technology)
• CVE – (s) Cape Verde escudo (ISO 4217 currency code)
• CVI – (i) Combat Vehicle Identification
• CVLL – (i) Crypto Variable Logic Label
• CVR – (i) Cockpit Voice Recorder – Combat Vehicle Reconnaissance
• CVR(T) – (i) Combat Vehicle Reconnaissance (Tracked)
• CVS – (i) Concurrent Versions System
• CVSD – (i) Continuous Variable Slope Delta (modulation)
• CVT – (i) Continuously Variable Transmission

CW

• CW – (i) Continuous Wave – Clothes Washer - (s) Cook Islands (FIPS 10-4 territory code)
• CW/CE – (i) Construction Worker / Construction Electrician IBEW
• CWC – (i) Chemical Weapons Convention
• CWS – (i) Canadian Wildlife Service
• CWRU – (i) Case Western Reserve University

CX

• CX – (s) Christmas Island (ISO 3166 digram) – One Hundred and Ten (in Roman numerals)
• CXR – (s) Christmas Island (ISO 3166 trigram)

CY

• cy – (s) Welsh language (ISO 639-1 code)
• CY – (i) Calendar year – (s) Cyprus (ISO 3166 and FIPS 10-4 country code digram)
• cym – (s) Welsh language (ISO 639-2 code)
• CYM – (s) Cayman Islands (ISO 3166 trigram)
• CYP – (s) Cyprus (ISO 3166 trigram) – Cyprus pound (ISO 4217 currency code)

CZ

• CZ – (i) Combat Zone – (s) Czech Republic (ISO 3166 and FIPS 10-4 country code digram)
• CZE – (s) Czech Republic (ISO 3166 trigram)
• CZK – (s) Czech koruna (ISO 4217 currency code)
• CZF - (a) (Christian Zombie Fan)
• CZMA – (i) (US) Coastal Zone Management Act