A... AA Auto Answer AAB All-to-All Broadcast AAL Asynchronous Transfer Mode Adaptation Layer AAP Applications Access Point [DEC] AAS All-to-All Scatter AASP ASCII Asynchronous Support Package AAT Average Access Time ABC * Atanasoff-Berry Computer (First digital Calculating machine that used vacuum tubes) ABEND Abnormal End ABI Application Binary Interface ABIOS Advanced BIOS ABIST Automatic Built-In Self-Test [IBM] ABLE Adaptive Battery Life Extender ABR Available Bit Rate ABRS Automated Book Request System [British Library] ABS Absolute ABT Abort ABTS ASCII Block Terminal Services AC Autocheck + Automatic Computer + Alternating Current ACC Accumulator ACD Automated Call Distribution + Automatic Call Distributor ACDI Asynchronous Communications Device Interface ACE Advanced Computing Environment [SCO] + Adverse Channel Enhancements [Microcom] + * Automatic Computing Engine ACF Access Control Field + Advanced Communications Function ACH Automated Clearing House ACIAS Automated Calibration Interval Analysis System ACIS American Committee for Interoperable Systems ACK Acknowledgment ACL Access Control List ACM Association for Computing Machinery Audio Compression Manager [Microsoft] ACMS Application Control Management System ACP Ancillary Control Program + Auxiliary Control Process ACROSS Automated Cargo Release and Operations Service System ACS Access + Access Control Set + Access Control System + Asynchronous Communication Server ACTS Automated Computer Time Service ACTT Advanced Communication and Timekeeping Technology [Seiko] ACU Automatic Calling Unit A/D Analog to Digital ADA Automatic Data Acquisitions + Programming Language named after Augusta Ada Lovelace) ADB Apple Desktop Bus ADC Adaptive Data Compression (protocol) [Hayes] + 1 Add with Carry + Analog to Digital Converter ADCCP Advanced Data Communication Control Procedures ADD Automatic Document Detection [WordPerfect] ADF Automatic Document Feeder + Automatically Defined Function .ADF Adapter Description File (file name extension) ADI AutoCAD Device Interface (driver) ADL Address Data Latch ADLAT Adaptive Lattice Filter ADLC Adaptive Lossless Data Compression [IBM] + Asynchronous Data Link Control ADMACS Apple Document Management and Control System ADMD Administrative Management Domain [X.400] .ADN Add In Utility (file name extension) [Lotus 1-2-3] [LDC] ADP Automatic Data Processing ADPCM Adaptive Differential Pulse Code Modulation ADR Address ADS Application Development Solutions [AT&T] + Application Development System + Automatic Distribution System ADSC Address Status Changed ADSL Asymmetrical Digital Subscriber Line ADSR Attack, Decay, Sustain, Release ADT Application Data Types ADU Automatic Dialing Unit AE Above or Equal AEB Analog Expansion Bus [Dialogic] AF Auxiliary carry Flag AFA Accelerated File Access AFC Automatic Font Change AFD Automatic File Distribution AFII Association for Font Information Interchange AFIRM Automated Fingerprint Image Reporting and Match AFIS Automated Fingerprint Identification System .AFM Adobe Font Metrics (file name extension) [Adobe Systems] AFP Appletalk Filing Protocol [Macintosh] AFS Andrew File System (protocols) AFTP Anonymous File Transfer Protocol AGC Automatic Gain Control AGRAS Antiglare-Antireflective-Antistatic AI Analog Input + Artificial Intelligence AIA Applications Integration Architecture [DEC] AIC AIXwindows Interface Composer [IBM] AIF Audio Interchange Format AIIM Association for Information and Image Management AIN Advanced Intelligent Network [Bell Atlantic] AISB Association of Imaging Service Bureaus AISP Association of Information Systems Professionals AIX Advanced Interactive Executive [IBM] ALC Arithmetic and Logic Circuits + Automatic Level Control ALE Address Latch Enable ALGOL Algorithmic Oriented Language (see IAL) ALIBI Adaptive Location of Internet worked Bases Of Information 2 ALINK Active Link [HTML] ALIWEB Archie like Indexing in the Web [Internet] ALN Asynchronous Learning Network ALR Advanced Logic Research, Inc. ALT Alternate (mode) ALT. Alternate lifestyle [USENET Newsgroup Category] ALU Arithmetic Logic Unit AMANDDA Automated Messaging and Directory Assistance AMD Active Matrix Display + Advanced Micro Devices, Inc. AMI American Megatrends, Inc. AMMA Advanced Memory Management Architecture [Everex Systems] AMPS Advanced Mobile Phone Service ANCOVA Analysis of Covariance ANI Automatic Number Identification .ANI Animated Cursor (file name extension) [Microsoft] ANN Artificial Neural Network .ANN Annotations (file name extension) [IBM] ANOVA Analysis Of Variance ANSI American National Standards Institute AO Analog Output AOCE Apple Open Collaboration Environment AOE Application Operating Environment [AT&T] AOL America Online AOS Add or Subtract AP Adjunct Processor + Application Processor A/P Accounts Payable APA Adaptive Packet Assembly + All Points Addressable + Arithmetic Processing Accelerator APAR Authorized Program Analysis Report [IBM] APAREN Address Parity Enable [IBM] APCUG Association of PC User Groups API Application Program Interface APIC Advanced Programmable Interrupt Controller (bus) [Intel] APIS Advanced Passenger Information System APL A Programming Language (Mathematics) APM Advanced Power Management [IBM OS2] .APP Application (file name extension) [R: Base] APPC Advanced Program-to-Program Communications [IBM] APPI Advanced Peer-to-Peer Internetworking APPN Advanced Peer-to-Peer Networking [IBM] APPS Applications APRP Adaptive Pattern Recognition Processing APS Advanced Photo System + Asynchronous Protocol Specification APSE ADA Programming Support Environment APT Address Pass Through + Advanced Parallel Technology + Automatically Programmed Tools A/R Accounts Receivable ARA AppleTalk Remote Access ARAG Antireflective-Antiglare ARAS Antireflective-Antistatic .ARC Archive (file name extension) ARCA Advanced RISC Computing Architecture 3 ARCnet Attached Resource Computer Network .ARJ Compressed File (file name extension) [Jung] ARL Adjusted Ring Length ARLL Advanced Run Length Limited ARM Advanced RISC Machine (processor) + Annotated Reference Manual + Asynchronous Response Mode ARMA Association of Records Managers and Administrators ARP Address Resolution Protocol [Novell] ARPANET Advanced Research Projects Agency Network ARPL Adjust Requested Privilege Level ARTA Apple Real Time Architecture ARTIC A Real-Time Interface Compressor [IBM] ARTS Asynchronous Remote Takeover Server ARTT Asynchronous Remote Takeover Terminal ARQ Automatic Repeat Request ARU Audio Response Unit AS Autonomous System [Internet] ASAP As Soon As Possible + Automatic Switching and Processing AS3AP ANSI SQL Standard Scalable and Portable .ASC ASCII text (file name extension) ASCII American Standard Code for Information Interchange ASIC Application-Specific Integrated Circuit ASIT Advanced Security and Identification Technology ASL Adaptive Speed Leveling ASLM Apple Shared Library Manager [Macintosh] .ASM Assembler Source Language (file name extension) ASMP Asymmetric Multiprocessing ASN Abstract Syntax Notation + Autonomous System Number ASP Association of Shareware Professionals ASPI Advanced SCSI Programming Interface [Adaptec] ASPS Advanced Signal Processing System ASR Address Space Register + Automatic Send-Receive + Automatic Speech Recognition AST AST Research, Inc. (named from first initials of The founders: Albert Wong, Safi Qureshey, Thomas Yuen) ASYNC Asynchronous AT Advanced Technology + Attention ATA Advanced Technology Attachment ATDP Attention Dial Pulse ATDT Attention Dial Tone ATE Automated Test Equipment ATG Advanced Technology Group ATH Attention Hang-Up (Modem command) ATM Adobe Typeface Manager + Asynchronous Transfer Mode + Automated Teller Machine ATPS AppleTalk Printing Services [Macintosh] ATR Automatic Terminal Recognition ATS Administrative Terminal System + Apple Terminal Services AT&T American Telephone and Telegraph ATTN Attention ATTRIB Attribute (also ATR) 4 ATZ Attention Restore configuration profile from Nonvolatiles RAM (Modem command) .AU Audio (file name extension) AUDIT Automated Data Input Terminal AUI Attachment Unit Interface AUP Acceptable Use Policy [Internet] AUTO Automatic AUTOEXEC Automatic Execution AUX Auxiliary + (First Serial Port) AV Audio/Video + Audiovisual AVA Audio Visual Authoring [IBM] AVC Audio Visual Connection [IBM] AVG Average AVI Audio Visual Interleave [Microsoft] AVR Automatic Voice Recognition AWG American Wire Gage AWK (UNIX language named after its authors... Al Aho, Peter Weinberger and Brian Kernighan) AWS Advanced Workstations and Systems (group) [IBM] AX Architecture Extended + Automatic Transmission B... BAK Binary Adaptation Kit [Microsoft] .BAK Backup (file name extension) BAL Basic Assembly Language BALUN Balanced Unbalanced (device) BAM Boyan Action Module BARTS Bell Atlantic Regional Timesharing .BAS Basic Language (file name extension) BASH Bourne Again Shell [UNIX] BASIC Beginner's All-purpose Symbolic Instruction Code BASM Built-In Assembler BAT Block Address Translation .BAT Batch Processing (file name extension) BBS Bulletin Board System BCC Block Check Character BCC: Blind Carbon Copy BCD Binary Coded Decimal BCL Batch Command Language BCN Beacon BCP Best Current Practice + Bulk Copy Program BCPL Basic Computer Programming Language BCR Byte Count Register BCS Bar Code Sorter BDA Bios Data Area BDE Borland Database Engine [Borland] BDOS Basic Disk Operating System BDR Bus Device Request BE Below or Equal BEL Bell BELLCORE Bell Communications Research BERT Bit Error Rate Test/Tester BF Bad Flag 5 B/F Background/Foreground BFF Binary File Format [IBM] BFT Binary File Transfer BGA Ball Grid Array BGCOLOR Background Color [HTML] BGE Branch if Greater or Equal .BGI Borland Graphic Interface (file name extension) BGP Border Gateway Protocol BGT Branch if Greater Than BHI Branch if Higher BHIS Branch if Higher or Same BI Binary Input .BIB Bibliography (file name extension) BiDi Bi-Directional BIM Beginning of Information Marker .BIN Binary (file name extension) BINAC * Binary Automatic Computer BIOS Basic Input/Output System BIS Business Information System BISDN Broadband Integrated Services Digital Network BIST Built-In Self-Test BiSYNC (See BSYNC) BIT Binary Digit BITNET Because It's Time Network BITNIC Bitnet Network Information Center BIU Bus Interface Unit BIX Byte Information Exchange (BBS) BIZ. Business [USENET Newsgroup Category] .BK! Backup (file name extension) [WordPerfect] .B~K Backup (file name extension) BKSP Backspace BL Backlit BLAST Blocked Asynchronous Transmission (protocol) [Communications Research Group] .BLD BASIC Bload Graphics (file name extension) BLE Branch if Less or Equal BLER Block Error BLK Block BLMC Buried Logic Macrocell BLOB Binary Large Object BLOS Branch if Lower Or Same BMI Branch if Minus BMIC BusMaster Interface Controller [Intel] BMP Basic Mapping Support + Batch Message Processing Program .BMP Bitmap Picture (file name extension) BNC Bayonet Neill-Concelman (connector used with Coaxial cable invented by Mr. Neill-Concelman) BNE Branch if Not Equal BNS Backbone Network Service BO Binary Output BoB Break-out Box BOC Basic Operator Console BOM Beginning Of Message BOOTP Bootstrap Protocol [Internet] BOPS Billion Operations Per Second BORPQU Borland Pro Quattro BORQU Borland Quattro 6 BOS Basic Operating System BOT Beginning of Table + Beginning of Tape BP Base Pointer BPB BIOS Parameter Block BPI Bits per Inch BPL Branch if Plus BPS Bits per Second + Bytes per Second BR Bad Register BRGC Binary Reflected Gray Code BRI Basic Rate Interface + Brain Response Interface BS Backspace BSAM Basic Sequential Access Method BSC Binary Synchronous Communication .BSC Boyan Script (file name extension) [Boyan Communications] BSCS Bachelor of Science (Degree) in Computer Science BSD Berkely Software/Standard Distribution BSF Bit Scan Forward BSI British Standards Institute BSR Bit Scan Reverse BSS Block Started by Symbol BSV BASIC Bsave Graphics (file name extension) BSY Busy BSYNC Binary Synchronous Communications (protocol) BT Bit Test BTAM Basic Telecommunications Access Method [IBM] BTB Branch Target Buffer BTC Bit Test and Complement BTOA Binary To ASCII BTP Batch Transfer Program BTR Bit Test and Reset BTS Bit Test and Set BU Branch Unit BUBL Bulletin Board for Libraries [Janet] BUF Buffer BVH Base Video Handler BWM Block-Write Mode B2X Binary To Hexadecimal [REXX] BYTE Binary Element String C... C C Programming Language .C C source code (file name extension) [C] CA Collision Avoidance 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 CAEX Computer Aided Exploration CAG Column Address Generator CAI Computer Aided Instruction CAL Calendar + Computer Aided Learning CAM Common Access Method + Computer Aided Manufacturing + Contents Addressable Memory 7 CAN Cancel CAP Carrierless Amplitude and Phase-Modulation + Central Arbitration Point + Communication Application Platform + Computer Aided Publishing .CAP Capture (file name extension) CAPD Computing To Assist Persons with Disabilities [Johns Hopkins University] 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 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 CBC Cipher Block Chaining CBCR Channel Byte Count Register CBEMA Computer and Business Equipment Manufacturers Association CBGA Ceramic Ball Grid Array CBI Computer Based Instruction CBL Computer Based Learning .CBL COBOL source code (file name extension) CBMS Computer-Based Mail System CBR 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 CCITT Comite Consultatif International Telegraphique ET Telephonique/ Consultative Committee for International Telegraph and Telephone CCL Connection Control Language CCP 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 8 C2D Character to Decimal [REXX] CDA Compound Document Architecture [DEC] CDC Control Data Corporation CD_CHRDY Card Channel Ready [IBM] CD-DA Compact Disk -Digital Audio CDDI Copper Distributed Data Interface CDE Common Desktop Environment + Complex Data Entry .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 CDPD Cellular Digital Packet Data CDR Call Detail Record + Call Detail Recording CD-R Compact Disk - Recordable 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 CDS Current Directory Structure .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 CEMS Constituent Electronic Mail System CEOP Conditional End of Page CERN the European Particle Physics Laboratory (initials Originally from Conseil European pour la Recherché Nucleaire) CERT Computer Emergency Response Team CFB Cipher Feedback + Configurable Function Block .CFG Configuration (file name extension) CFM Code Fragment Manager [Macintosh] CFR Computerized Facial Recognition CFS Common File System CFV Call For Votes [Bitnet] CGA Color Graphics Adapter CGE Common Graphics Environment CGI Common Gateway Interface + Computer Generated Images + Computer Graphics Interface .CGM Computer Graphics Metafile (file name extension) + Graph (file name extension) [Lotus 1-2-3] [LDC] CHAP Challenge Authentication Protocol (protocol) CHAR Character CHAT Conversational Hypertext Access Technology [Internet] CHCK Channel Check CHCP Change Code Page CHDIR Change Directory 9 CHFN Change Finger [Unix] CHGRP Change Group .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 CIA Current Instruction Address CICS/VS Customer Information Control System/ Virtual Storage [IBM] CID Configuration/Installation/Distribution CIDR Classless Interdomain Routing CIF Common Interchange/Intermediate Format + Customer Information Feed CIM CompuServe Information Manager + Computer Integrated Manufacturing CIO Chief Information Officer CIOCS Communication Input/Output Control System CIP Command Interface Port CIR Committed Information Rate CIRC Circular Reference 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 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 CLI Call-Level Interface + Clear Interrupt Flag + Command Line Interface CLIST Command List CLK Clock CLNP Connectionless Network Protocol CLP Cell Loss Priority + Constraint Logic Programming .CLP Clipboard (file name extension) [Windows] CLS Clear Screen CLTP Connectionless Transport Protocol CLTS Clear Task Switch Flag 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 + 10