# List of acronyms: 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 if it were a word, e.g., SARS = severe acute respiratory syndrome, pronounced to rhyme with cars
* initialism = an abbreviation pronounced wholly or partly using the names of its constituent letters, e.g., CD = compact disc, pronounced cee dee
* pseudo-blend = an abbreviation whose extra or omitted letters mean that it cannot stand as a true acronym, initialism, or portmanteau (a word formed by combining two or more words).
    (a) = acronym, e.g.: SARS – (a) severe acute respiratory syndrome
    (i) = initialism, e.g.: CD – (i) compact disc
    (p) = pseudo-blend, e.g.: UNIFEM – (p) United Nations Development Fund for Women
    (s) = symbol (none of the above, representing and pronounced as something else; for example: MHz – megahertz)
Some terms are spoken as either acronym or initialism, e.g., VoIP, pronounced both as voyp and V-O-I-P.
(Main list of acronyms)

## Contents

* Top
* C0–9 CA CB CC CD CE CF CG CH CI CJ CK CL CM CN CO CP CQ CR CS CT CU CV CW CX CY CZ
* c – (s) Centi
* C – (s) Carbon – Coulomb – One Hundred (in Roman numerals)

## C0–9

* C2 or C$^2$ – (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 C$^2$D – (i) Intel Core 2 Duo
* C2IEDM or C$^2$IEDM – (i) Command and Control Information Exchange Data Model
* C2IS or C$^2$IS – (i) Command and Control Information System
* C2PC or C$^2$PC – (i) Command and Control Personal Computer
* C2V or C$^2$V – (i) Command and Control Vehicle
* C2W or C$^2$W – (i) Command and Control Warfare
* C3 or C$^3$
** (i) Colorectal Cancer Condition
** Command, Control, and Communications
* C3I or C$^3$I – (i) Command, Control, Communications, and Intelligence
* C4 or C$^4$ – (i) Command, Control, Communications, and Computers
* C4I or C$^4$I – (i) Command, Control, Communications, Computers, and Intelligence
* C4ISR or C$^4$ISR – (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
** (i) Closed Beta Test
** (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 Development & 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)
** (s) Consolidated Freightways
** 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
* [C.R.A.P. (acronym) Citizens Raging Against Phones] Group of people on GTA III (PS2)]
* 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
* [CWAJGA? (disambiguation) Can't We All Just Get Along?] Used in the 90s & early 2000s to resolve or stop arguments and disagreements between people

## 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