List of acronyms: C

(Main list of acronyms)


 * 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) Coast to Coast Athletic Conference
 * Consumer-To-Consumer electronic commerce
 * Cam-To-Cam internet chat
 * C2D or C2D – (i) Intel Core 2 Duo
 * 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
 * Coastal Athletic Association or its former name of Colonial Athletic Association
 * CAAT
 * (i) or (a) Campaign Against Arms Trade
 * Center for Alternatives to Animal Testing
 * CABB (p/i) – Confederación Argentina de Básquetbol (Spanish, "Argentine Basketball Confederation")
 * CAC
 * (i) California Association of Criminalists
 * Chronic Asymptomatic [Disease] Carrier
 * CACM
 * (i) Central American Common Market
 * (i) Communications of the ACM
 * CAD
 * (s) Canadian dollar (ISO 4217 currency code)
 * (a) Computer-Aided Design
 * Computer-Aided Dispatch
 * Cpplint Anxiety Disorder - (a) Condition suffered by software developers who worry about whether they've left any whitespace on the end of a line
 * CADCAM – (a) Computer-Aided Design/Computer-Aided Manufacturing
 * CADMID – (a) Concept, Assessment, Demonstration, Manufacture, In service, Disposal (life cycle mnemonic)
 * CADPAT – (p) CAnadian Disruptive PATtern
 * CADT – Child/Adolescent Day Treatment
 * 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
 * CalSTRS – (p) California State Teachers' Retirement System
 * Caltrans – (p) California Department of Transportation
 * 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
 * CAQ – (i) Coalition Avenir Québec (French, "Coalition for Québec's Future"; political party in that Canadian province)
 * CARB (i) – California Air Resources Board
 * 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
 * CASA –(a) Civil Aviation Safety Authority
 * 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
 * CAVE - Citizens Against Virtually Everything
 * 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
 * CBN – CardsApp Brand Number
 * 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
 * CBP – (i) (U.S.) Customs and Border Protection
 * CBR – (i) Case-Based Reasoning
 * CBRE
 * (i) Canadian Brotherhood of Railway Employees
 * Certified broadcast radio engineer (U.S. professional certification)
 * Chemical, Biological, Radiological and Explosive Defence Group (Singapore)
 * Coldwell Banker Richard Ellis
 * 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) Cock and Ball Torture
 * (i) Cognitive Behaviour Therapy
 * (p) Combat
 * CBUS – (i) Columbus, Ohio

CC

 * CC – many, including carbon copy; see entry
 * CCA – (i) Counter Command Activity
 * CCCAA – (p/i) California Community College Athletic Association (usually pronounced "3C-2A")
 * CCC
 * CCC - (p/i) Coricidin Cough & Cold
 * 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 requirement
 * 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
 * Cape Cod Mall
 * CCOC
 * (i) Canadian Children's Opera Chorus
 * 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) Covenants, conditions, and restrictions (related to real estate, especially in the US)
 * 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
 * CDL – (i) Commercial driver's license
 * CDM
 * (i) Clean Development Mechanism (Kyoto protocol)
 * Cold Dark Matter (astronomy)
 * CDMA – (i) Code Division Multiple Access
 * CDMO – (i) Contract Developpement & Manufacturing Organizations
 * CDMSII – (p) Cryogenic Dark Matter Search II
 * CDMX – (p) Ciudad de México, the Spanish name of Mexico City
 * 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 – (p) 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 of 1980 (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
 * Confédération européenne de volleyball (French, "European Volleyball Confederation")
 * 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
 * College Football Association (former consortium of US major college football conferences)
 * Color Filter Array
 * County Fire Authority
 * Covering Force Area
 * CFAR
 * (i) Christine's
 * Federal Acquisition Regulation
 * CFC
 * (i) ChloroFluoroCarbon
 * Canadian Fish Company
 * CFE – (i) Constitution for the Federation of Earth
 * 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
 * CFP
 * (i) Call for papers
 * College Football Playoff
 * Common Fisheries Policy (EU)
 * 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 – Controls Group – (s) Democratic Republic of the Congo (FIPS 10-4 country code) – Republic of the Congo (ISO 3166 digram)
 * 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 – ch(L) is used to denote the Chern character of a line bundle
 * 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 – (a) Clearing House Automated Payment System
 * CHDK – (i) Canon Hack Development Kit (Canon camera firmware hack)
 * 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
 * Catholic Health Initiatives (US hospital network)
 * (s) Chile (IOC and FIFA trigram, but not ISO 3166)
 * (i) Columbia Helicopters, Inc
 * 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
 * CHPSO – (a) California Hospital Patient Safety Organization
 * CHRS – Canadian Heart Rhythm Society
 * 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
 * Cru' in Action
 * 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
 * CICS – (a) Customer Information Control System (IBM mainframe software; "kicks" or "C-I-C-S")
 * CID
 * (i) Certified Interior Designer (New York State professional licensing designation)
 * (p) Combat Identification
 * (i) Criminal Investigation Division
 * Criminal Investigations Department
 * CIÉ – (i) Commission internationale de l'éclairage
 * CIEF – (i) Comité international d'enregistrement des fréquences (International Frequency Registration Board)
 * CIF
 * (i) California Interscholastic Federation (high school sports governing body)
 * 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 Object 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, a former name of the organization now known as U Sports
 * 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

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
 * Country Music Association (also used to refer to the organization's annual awards)
 * 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
 * CMIIAW – (i) Correct me if I am wrong
 * CMIS
 * (a) Content Management Interoperability Services
 * 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, "World Wrestling Council"—Mexican professional wrestling promotion)
 * CMM – (i) Capability Maturity Model
 * CMMC – (i) Corps Materiel Management Centre
 * CMML
 * (i) Chronic MyeloMonocytic Leukemia
 * Continuous Media Markup Language
 * CMO – (i) Civil-Military Operations
 * CMOC – (i) Civil-Military Operations Centre
 * CMOS
 * (i) Canadian Meteorological and Oceanographic Society
 * (The) Chicago Manual of Style
 * 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
 * (i) Charlotte-Mecklenburg Police Department
 * (i) Costa Mesa Police Department
 * CMR
 * (s) Cameroon (ISO 3166 trigram)
 * (i) Coaxial Main Rotors (helicopter type)
 * CMS
 * (i) Centers for Medicare and Medicaid Services
 * The Chicago Manual of Style
 * CMT – (i) Country Music Television
 * CMU
 * (i) Carnegie Mellon University
 * Central Michigan University
 * Concrete Masonry Unit
 * CMW
 * (i) 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 (color model)

CN

 * CN
 * (i/s) Canadian National (railway; also the AAR reporting mark for said company)
 * (s) China (ISO 3166 digram)
 * Comoros (FIPS 10-4 country code)
 * CNA
 * (i) Center for Naval Analyses
 * Certified Network Administrator
 * Computer Network Attack
 * Continental (Casualty Company), National (Fire Insurance Company), and American (Casualty Company), the three companies that merged to form what is now known as CNA Financial
 * 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
 * CNES – (i) Centre national d'études spatiales (French, "National Centre for Space Studies")
 * CNF – (p) Cost and Freight
 * 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
 * COBRA – Consolidated Omnibus Budget Reconciliation Act of 1985
 * 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)
 * (i) Cost of Living
 * 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)
 * COMLEX-USA – (p/a) Comprehensive Osteopathic Medical Licensing Examination of the United States (of America); "COMLEX" typically pronounced as a single word, with "USA" spelled out
 * 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
 * COPD –(i) Chronic obstructive pulmonary disease
 * 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
 * COSHH – (p) Control Of Substances Hazardous to Health (United Kingdom)
 * CoSIDA – (p) College Sports Information Directors of America, the original name of the organization now known as College Sports Communicators
 * CoT – (i) Car of Tomorrow (former NASCAR race car design)
 * COTS – (a) Commercial Off The Shelf
 * COVID-19 – Coronavirus disease 2019
 * 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")
 * CPAP
 * (i) Center for Public Administration and Policy
 * Coalition for the Prevention of Alcohol Problems
 * Consecutive primes in arithmetic progression
 * (p) Continuous positive airway pressure ("see-pap")
 * CPC – Certified Professional Coder, a certification from AAPC
 * CPCU – Certified Property Casualty Underwriter
 * CPD – (i) Capabilities Production Document
 * CPE
 * (i) Certificate of Proficiency in English
 * Certified Professional Ergonomist
 * (i) Clinical Pastoral Education
 * CPEC – (p) China–Pakistan Economic Corridor ("see-pec")
 * CPF
 * (i) Calibration Parameter File
 * Canadian Patrol Frigate
 * CPG – (a) Clinical Practice Guideline
 * CPI – (i) CERDEC Command, Power and Integration
 * CPIM – (a) Certification on Production and Inventory Management
 * CPIR – Computationally-Private Information Retrieval
 * CPON – (i) Certified Pediatric Oncology Nurse
 * CPPCC – (i) Chinese People's Political Consultative Conference
 * CPR
 * (i) Canadian Pacific Railway
 * (i) Cardiopulmonary resuscitation
 * CPS
 * Crown Prosecution Service (UK government agency)
 * Child Protection Service (Collection of US government agencies)
 * 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)
 * C.R.E.A.M. –Cash Rules Everything Around Me
 * 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
 * CRISPR – (a) clustered regularly interspaced short palindromic repeats
 * CRM – (i) Cardiac Rhythm Management – Customer Relationship Management
 * CRO – (s) Croatia (IOC and FIFA trigram, but not ISO 3166) – Contract Research Organization
 * 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
 * Counter-Strike
 * (s) Costa Rica (FIPS 10-4 country code)
 * Serbia and Montenegro (ISO 3166 digram; obsolete since 2006)
 * CSA
 * (i) Canadian Soccer Association
 * Canadian Space Agency
 * Canadian Standards Association
 * Chief Scientific Advisor
 * 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)
 * College Sports Communicators (U.S. organization for college sports information directors)
 * Compact system camera
 * Computer Sciences Corporation (became DXC Technology in 2017)
 * Computer Security Centre
 * CSCC - Canadian Society of Clinical Chemists
 * 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
 * CSM – see entry
 * 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
 * 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 – Chrono Trigger (Computer/Video games) – (s) Connecticut (postal symbol) – Canterbury (postal symbol) – Chhattisgarh (Indian state code)
 * 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
 * (i) Carrie Underwood
 * (s) Cuba (FIPS 10-4 country code; ISO 3166 digram)
 * (i) University of Colorado Boulder
 * CUB – (s) Cuba (ISO 3166 trigram)
 * CUCV – (i) Commercial Utility Cargo Vehicle
 * CUDAAP –(a) Custom Database Applications
 * 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
 * (s) Cook Islands (FIPS 10-4 territory code)
 * (i) Clothes washer
 * (i) The CW
 * CW/CE – (i) Construction Worker / Construction Electrician IBEW
 * CWC – (i) Chemical Weapons Convention
 * CWL – (i) Campus Wide Login
 * 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)
 * (s) IATA code for Cam Ranh International Airport

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 – constructive Zermelo-Fraenkel
 * CZMA – (i) (US) Coastal Zone Management Act
 * CZW – (i) Combat Zone Wrestling