C C Programming Language
.C C source code (file name extension) [C]
CA Collision Avoidance
.CAB Cabinet (file name extension) [Microsoft]
CAD Computer Aided Design
CADD Computer Aided Design and Drafting
CADE Client/server Application Development Environment
CAE Client Application Enabler + Common Applications
Environment + Computer Aided Engineering
CAEN Chemically Assembled Electronic Nanocomputer
CAEX Computer Aided Exploration
CAG Column Address Generator
CAI Computer Aided Instruction
CAIRN Collaborative Advanced Interagency Research Network
CAL Calendar + Client Access License +
Computer Aided Learning
CALS Computer-Aided Acquisition in Logistic Support
CAM Common Access Method + Computer Aided Manufacturing +
Contents Addressable Memory
CAN Cancel
CANBUS Conroller Area Network Bus
CAP Carrierless Amplitude and Phase-Modulation +
Central Arbitration Point +
Communication Application Platform +
Competitive Access Provider +
Computer Aided Publishing
.CAP Capture (file name extension)
CAPD Computing To Assist Persons With Disabilities [Johns
Hopkins University]
CAPE Concurrent Art-to-Product Environment
CAPS Capitals (Upper Case Letters) +
Cassette Programming System
CARL Colorado Alliance of Research Libraries [Internet]
CAS Column Address Select +
Communications Application Specification +
Computer Aided Styling
CASE Computer Aided Software Engineering
CASL Crosstalk Application scripting Language [DCA]
CASS Computer Assisted Search Service
CASSIS Classified and Search Support Information System
CAT Computer Adaptive Test + Computer Aided Testing +
Computer Aided Tomography +
Computer Aided Transcription + Concatenate
.CAT Catalog (file name extension)
CATS Computer Assisted Training System
CAT SCAN Computerized Axial Tomography Scan
CATV Community Antenna Television (this was the original
name for what is now known as Cable TV)
CAU Controlled Access Unit
CAV Constant Angular Velocity
CAVE Computer Automatic Virtual Environment
CBC Cipher Block Chaining
CBCR Channel Byte Count Register
CBDS Connectionless Broadband Data Service
CBEMA Computer and Business Equipment
Manufacturers Association
CBGA Ceramic Ball Grid Array
CBI Computer Based InstructionInstrumentation
CBL Computer Based Learning
.CBL COBOL source code (file name extension)
CBMS Computer-Based Mail System
CBR Case Based Reasoning + Constant Bit Rate
CBT Computer Based Training
CBW Convert Byte to Word
CBX Computer-Controlled Branch Exchange
CC Cluster Controller
CC: Carbon Copy
CCD Charged-Coupled Device
CCFT Cold Cathode Fluorescent Tube
CCI Common Client Interface
CCIE Cisco Certified Internetwork Expert [Cisco]
CCITT Comite Consultatif International Telegraphique et
Telephonique/ Consultative Committee for International
Telegraph and Telephone
CCL Connection/Cursor Control Language
CCP Certified Computing Professional +
Console Command Processor
CCS Common Command Set + Common Communications Services +
Common Communications Support +
Continuous Composite Servo
.CCS Color Calibration System (file name extension)
CCSD Cellular Circuit-Switched Data
CD Carrier Detect + Change Directory +
Collision Detection + Color Display + Compact Disk
C/D Control Data
C2D Character To Decimal [REXX]
CDA Compound document Architecture [DEC]
.CDA CD Audio Track (file name extension)
CDBT Compact Disk-Based Training
CDC Control Data Corporation
CD_CHRDY Card Channel Ready [IBM]
CD-DA Compact Disk -Digital Audio
CDDI Copper Distributed Data Interface
CDE Common Desk Environment + Complex Data Entry
CD-E Compact Disk - Erasable
CDF Channel Definition Format
.CDF Comma Delimited Format (file name extension)
CDFS Compact Disc File System [Microsoft]
CD+G Compact Disk plus Graphics
CD-I Compact Disk - Interactive
CDIA Certified document Imaging Architect
CDL Computer Design Language
CDMA Code Division Multiple Access
CDMF Commercial Data Masking Facility [IBM]
CD-MO Compact Disk - Magneto Optical
CDOS Concurrent Disk Operating System
CDP * Certificate In Data Processing (First certification
for Computer Professionals)
CDPD Cellular Digital Packet Data
CDR Call Detail Record + Call Detail Recording +
Common Data Representation
CD-R Compact Disk - Recordable
CDRAM Cache DRAM
CD-RDx Compact Disk - Read Only Memory Data Exchange Standard
CDRL Contract Data Requirements List
CD-ROM Compact Disk - Read Only Memory
CD-RTOS Compact Disk - Real Time Operating System
CD-RW Compact Disk - Re-Writable
CDS Current Directory Structure
CDSA Common Data Security Architecture
CDSL Consumer Digital Subscriber Line [Rockwell]
.CDT Corel Draw Template (file name extension)
CD-V Compact Disk - Video
CD-WO Compact Disk - Write Once
.CDX Compound Index (file name extension) [Fox Pro]
CD-XA Compact Disk - Extended Architecture
CE Cache Enable + Chip Enable + Collision Elimination +
Convert Enable
CEG Continuous Edge Graphics
CEI Conducted Electromagnetic Interference
CELP Card Edge Low Profile (socket) [Intel]
CEMS Constituent Electronic Mail System
CEOP Conditional End Of Page
CER Canonical Encoding Rules
CERN The Europien Particle Physics Laboratory (initials
originally from Conseil European pour la Recherche
Nucleaire)
CERT Computer Emergency Response Team
CFB Cipher Feedback + Configurable Function Block
.CFG Configuration (file name extension)
CFM Code Fragment Manager [Macintosh] +
Cubic Feet Per Minute
CFML ColdFusion Markup Language
CFR Computerized Facial Recognition
CFS Caching/Common File System
CFV Call For Votes [Bitnet]
CG Control Gate
CGA Color Graphics Adapter
CGE Common Graphics Environment
CGI Computer Generated Images + Computer Graphics Interface
CGI-BIN Common Gateway Interface - Binary
.CGM Computer Graphics Metafile (file name extension) +
Graph (file name extension) [Lotus 1-2-3] [LDC]
CGS Continuous-Grain Silicon
CHAP Challenge-Handshake Authentication Protocol
CHAR Character
CHAT Conversational Hypertext Access Technology [Internet]
CHCK Channel Check
CHCP Change Code Page
CHDIR Change Directory
CHFN Change Finger [Unix]
CHGRP Change Group
CHIPS Clearinghouse Interbank Payments System
.CHK CHKDSK (file name extension)
CHKDSK Check Disk
CHMOD Change Mode
CHOWN Change Owner
CHP Chapter
CHR Character
CHRP Common Hardware Reference Platform
CHS Cylinder Head Sector
CHTML Compressed HTML
CI Component Interface
CIA Current Instruction Address
CIAC Computer Incident Advisory Capability
CICS/VS Customer Information Control System/
Virtual Storage [IBM]
CID Charge-Injection Device +
Configuration/Installation/Distribution
CIDR Classless Inter-Domain Routing
CIF Common Interchange/Intermediate Format +
Crystallographic Information File +
Customer Information Feed
CIFS Common Internet File System
CIM Common Information Model +
CompuServe Information Manager +
Computer Integrated Manufacturing
CIO Chief Information Officer
CIOCS Communication Input/Output Control System
CIP Command Interface Port + Common Indexing Protocol
CIR Committed Information Rate
CIRC Circular Reference +
Cross-Interleaved Reed-Solomon Code
CIS Card Information Structure + Client Information System +
CompuServe Information Service +
Computer Information Systems + Contact Image Sensor +
Customer Information System
CISC Complex Instruction Set Computing
CIT Computer-Integrated Telephony
CIVR Computer and Interactive Voice Response
CIX Commercial Internet Exchange +
Compulink Information Exchange
CJLI Command Job Language Interpreter
CKD Count Key Data (device)
CLAR Channel Local Address Register
CLASS Client Access to Systems and Services +
Cooperative Library Agency for Systems and Services +
Custom Local-Area Signaling Services
CLC Clear Carry Flag
CLD Clear Direction Flag
CLEC Competitive Local Exchange Carrier
CLI Call-Level Interface + Clear Interrupt Flag +
Client Library Interface + Command Line Interface
CLIB C Library
CLID Calling Line Identification
CLIST Command List
CLK Clock
CLNP Connectionless Network Protocol
CLOS Common Lisp Object System
CLP Cell Loss Priority + Constraint Logic Programming
.CLP Clipboard (file name extension) [Windows]
CLS Clear Screen
CLSID Class Identifier
CLTP Connectionless Transport Protocol
CLTS Clear Task Switch Flag
CLTV Constant Linear Time Velocity
CLUI Command Line User Interface
CLUT Color Look-Up Table
CLV Constant Linear Velocity
CM Centimeter + Control Mark + Corrective Maintenance
CMA Concert Multi-thread Architecture
CMC Common Mail Calls + Common Messaging Calls +
Communication Management Configuration +
Complement Carry Flag +
Computer-Mediated Communication [Internet]
CMD Circuit Mode Data
.CMD Command (file name extension)
CMF Creative Music Format
CNIDR Clearinghouse for Network Information and
Discovery and Retrieval [Internet]
CMIP Common Management Information Protocol
CMIS Common Management Information Services/System
CML Chemical Markup Language + Conceptual Modelling Language +
Computer Managed Learning + Current Mode Logic
CMM Capability Maturity Model
CMMS Computerized Maintenance Management Software
CMMU Cache/Memory Management Unit [Motorola]
CMOS Complementary Metal-Oxide Semiconductor
CMOV Conditional Move
CMP Compare + Computer
CMPS Compare word String
CMS Code Management System + Compiler Monitor System +
Conversation Monitor System
CMVC Configuration Management Version Control [IBM]
CMW Compartmented Mode Workstation
CMY Cyan-Magenta-Yellow (color model)
CMYK Cyan-Magenta-Yellow-Black (color model)
CNA Certified NetWare/Network Administrator
CNAPS Co-Processing Node Architecture for Parallel Systems
CNC Computerized Numerical Control
CNE Certified NetWare Engineer
.CNF Configuration (file name extension)
CNG Calling (tone)
CNI Certified Novell Instructor [Novell]
CNIDR Clearinghouse for Networked Information and Retrieval
CNN Composite Network Node
CNR Carrier to Noise Ratio
CNSS Core Nodal Switching Subsystem [Internet]
.CNT Contents (file name extension)
CNV Conventional (pertaining to Memory)
CNVT Convert
CNX Certified Network Expert
CO Central Office + Command Output + Convert Out
COAST Card On A Stick (module)
COAX Coaxial Cable
COB Chip-On-Board
.COB COBOL source code (file name extension)
COBOL Common Business-oriented Language (See HLL)
.COD Code List (file name extension)
CODASYL * Conference on Data System Languages (Group that
designed COBOL)
CODE Client-Server Open Development Environment
CODEC Coder/Decoder + Compression/Decompression
COEM Commercial Original Equipment Manufacturer
COFF Common Object File Format [Unix]
COGO Coordinate Geometry (Programming Language)
COL Collision + Computer Oriented Language
COLD Computer Output to Laser Disk
COLL Collision
COM Component Object Model [Microsoft] +
Computer Output Microfilm
.COM Command (file name extension) +
Commercial Business (Domain Name) [Internet]
COM1 First serial Port (asynchronous port)
COM2 Second serial Port
COM3 Third serial Port
COM4 Fourth serial Port
COMDEX Computer Dealers Exposition
COMET Cornell Macintosh Terminal Emulator
COMP Compare + Communications
COMP. Computers [USENET Newsgroup Category]
COMSAT Communications Satellite Corporation
CON Console (includes Keyboard and Screen)
COND Condition
CONFIG Configuration
CONS Connection-Oriented Network Service
CONTONE Continuous Tone
COPICS Communications Oriented Production Information
and Control System [IBM]
COR Common Object Runtime
CORBA Common Object Request Broker Architecture
CoREN Corporation for Research and Enterprise Network
COS Compatible Operating System
COSE Combined Office Standard Environment +
Common Open Software/Systems Environment
COSMIC Computer Software Management and Information
Center [NASA]
COSMOS Computer System for Mainframe Operations
COSS Common Object Services Specification
COTS Commercial Off-The-Shelf
CP Copy Protected
CPA Certified Public Accountant
CPC Constant Point Calculation
CPCS Check Processing Control System [IBM]
CPE Central Processing Element +
Customer Premises Equipment +
Customer Provided Equipment
.CPE Cover Page (file name extension)
CPG Clock Pulse Generator
CPI Characters Per Inch + Clock Per Instruction +
Common Programming Interface [IBM]
.CPI Code Page Information (file name extension) [MS-DOS]
CPI-C Common Programming Interface for Communications [IBM]
CPIO Copy In and Out [Unix]
CPL Current Privilege Level
.CPL Control Panel (file name extension)
CPLD Complex Programmable Logic Device
CPM Critical Path Method
CP/M Control Program for Microcomputers [Digital Research]
CPS Characters Per Second + Cycles Per Second
CPT Command Pass Through
CPU Central Processing Unit
CPW Commercial Processing Workload [IBM]
CR Carriage Return
CRAM Cyberspatial Reality Advancement Movement
CRAYON Create Your Own Newspaper
CRC Cyclic Redundancy Check
.CRD Cardfile (file name extension) +
Chord (music file name extension)
CREN Computer Research Education Network +
Corporation for Research and Education Networking
CRF Cable Retransmission Facility + Cross Reference File
CRI Color Reproduction Indices
CR/LF Carriage Return/Line Feed
CRM Customer Relationship Management
CROM Control Read Only Memory
CRT Cathode Ray Tube
CRTC CRT Controller
CRUD Create, Retrieve, Update, Delete
CS Chip Select + Clear to Send + Code Segment
C/S Client/Server
CSA Calendaring and Scheduling API [IBM]
CSAR Channel System Address Register
CSCW Computer Supported Cooperative Work
CSD Circuit-Switched Data +
Computer Services Department +
Corrective Service Diskette [IBM]
CSDS Circuit Switched Data Service
CSE Certified System Engineer
CSFI Communication Subsystem For Interconnection
CSG Constructive Solid Geometry +
Consulting Services Group [Lotus]
CSI Command Sequence Introducer + CompuServe Incorporated
CSID Call Subscriber ID
CSL Computer Sensitive Language
CSLIP Compressed Serial Line Interface Protocol [Internet]
CSM Code Set Map (file) + Communications Services Manager
CSMA/CA Carrier Sense Multiple Access/with Collision Avoidance
CSMA/CD Carrier Sense Multiple Access/with Collision Detection
CSMS Customer Support Management System
CSN Card-Select Number
CSNET Computer Science Network
CSO Central Services Organization
CSP Certified Systems Professional +
Chip-Scale Packaging +
Commercial Service Provider +
  Commercial Subroutine Package +
CompuCom Speed Protocol [CompuCom] +
Communicating Sequential Processes +
Cross System Product [IBM]
CSPDN Circuit Switched Public Data Network
CSRAM Custom Static RAM
CSS * Continuous System Simulator (Language)
CSS Cascading Style Sheet [Microsoft] +
Contact Start-S
CSSM Client-Server Systems Management [IBM]
CS/SS Card Service/Socket Service
CSTA Computer-Supported Telephony Applications
CSU Channel Service/Switching Unit
CSV Circuit-Switched Voice +
Comma-Separated value/Variable +
Common Services Verbs (interface) [Microsoft]
C&T Chips and Technologies
CTB Cipher Type Byte
CTC Channel To Channel
CTCP Client-To-Client Protocol
CTI Computer-Telephony Integration
CTOS Computerized Tomography Operating System +
Convergent Technologies Operating System
CTPA Coax-to-Twisted-Pair Adapter
CTRCO * Calculating,Tabulating,Recording Company (The name of
this company was changed to "International Business
Machines" by Thomas J. Watson, Sr.)
CTRL Control
CTS Clear To Send + Computer Telephony Solution [IBM] +
Customer Telephone System
CTSS * Compatible Time Sharing System
CUA Common User Access [IBM]
CUB Cursor Backward
CUD Cursor Down
CUE Custom Updates and Extras (card) [Egghead Software]
CUF Cursor Forward
CUI Character-Oriented User Interface +
Common User Interface [IBM]
CUP Cursor Position
CUPID Completely Universal Processor I/O Design [AST]
.CUR Cursor (file name extension)
CUSIP Committee for Uniform Security Identification
Procedures [U.S. Treasury]
CUT Control Unit Terminal
CUTE Clarkston University Terminal Emulator
CUU Cursor Up
CVF Compressed Volume File
CVGA Color Video Graphics Array
CVIA Computer Virus Industry Association
CVT Convert
CVW CodeView for Windows
CWD Convert Word to Double Word +
Change Working Directory [Internet]
CWIS Campus Wide Information Service/System [Internet] +
Community Wide Information Service/System [Internet]
C2X Character To Hexadecimal [REXX]
CYL Cylinder
CYMK Cyan-Yellow-Magenta-Black (color model)