This is a list of acronyms and initialisms.

For the purpose of this list, an acronym is an abbreviation that is pronounced as a series of constituent letters, and an initialism is an abbreviation whose pronunciation is wholly or partly the names of constituent letters. Also, a pseudo-blend is an abbreviation that is not really an acronym, nor an initialism nor a true portmanteau word, usually due to extra or omitted letters.

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

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

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

Add new entries here

Please add your own, in a quasi-dictionary order with lowercase treated the same as uppercase. This means that only alphanumeric characters are significant to determine the order, and that lowercase letters occupy the same ordering position as uppercase. For example: Algol appears before ALS. This differs from a strict ASCII ordering. 0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

• 2D - (i) Two-dimensional
• 2.5D - (i) "Two-and-a-half-dee": two-dimensional computer graphics imitating 3D
• 2G - (i) Second-generation mobile (cellular, wireless) telephone system
• 2.5G - (i) Second-and-a-half-generation mobile telephone system
• 3D - (i) Three-dimensional
• 3G - (i) Third-generation mobile telephone system
• 3M - (i) Minnesota Mining and Manufacturing Company
• 4D - (i) Four-dimensional (usually three spatial plus one temporal dimension, sometimes 4 spatial ones)
• 4G - (i) Fourth-generation mobile telephone system
• 4GL - (i) Fourth-generation programming language
• 4WD - (i) Four wheel drive (cf. AWD)

• A4 - (i) many, including a European standard office paper size; see entry

AA

• AA - (i) Alcoholics Anonymous - Automobile Association
• AAA - (p) American Automobile Association ("Triple-A") - anti-aircraft artillery - Administration, Authorization, and Authentication
• AAD - (i) analogue analogue digital - Australian Antarctic Division
• AARP - (i) formerly American Association of Retired Persons, but now officially known only by the initials
• AAS - (i) American Astronomical Society; pronounced "Double-A S"

AB

• ABA - (i) American Bar Association / American Basketball Association / Australian Broadcasting Authority
• ABB - (i) ASEA Brown Boveri (Swiss-Swedish multinational company)
• ABBA - (a) Agneta, Benny, Björn, Anni-Frid (the Swedish pop group)
• ABC - (i) alcoholic-beverage commission - alien big cat - Always Be Careful - American-Born Chinese - American Broadcasting Company - anti-lock brake controller - Associated British Corporation - Atanasoff Berry Computer - Atlantic Baptist College - Atomic Biological Chemical (see NBC) - Australian Broadcasting Corporation
• ABET - (a) Accreditation Board for Engineering and Technology
• ABL - (i) American Basketball League
• ABLE - (a) Airborne law enforcement (police air support unit)
• ABM - (i) anti-ballistic missile - Asynchronous Balanced Mode - automated banking machine
• ABN - (i) Australian Business Number - a number issued by the Australian government as registration of a business (used for taxation purposes)
• ABS - (i) acrylonitrile butadiene styrene - anti-lock braking system

AC

• AC - (i) adriamycin-cyclophosphamide (chemotherapy) - alternating current - Anonymous Coward - ante christum - air conditioning - Albert Champion - Associazione Calcio (Italian, "football (soccer) club")
• ACC - (i) Automatic Climate Control - Atlantic Coast Conference - Air Combat Command
• ACCAC - (a) Awdurdod Cymwysterau, Cwricwlwm ac Asesu Cymru (Qualifications, Curriculum and Assessment Authority for Wales)
• ACE - (a) Automatic Computing Engine - Air Combat Emulator (computer game)
• ACES - (a) Aerolineas Centrales de Colombia
• ACF - (i) American Culinary Federation
• ACK - (p) Acknowledge (telecommunications) (cf. NAK)
• ACL - (i) Access Control List / anterior cruciate ligament
• ACLU - (i) American Civil Liberties Union
• ACM - (i) see entry
• ACN - (i) Australian Company Number - a number issued by the Australian government as registration of a company (limited liability) in Australia.
• ACORN - (i) Association of Community Organizations for Reform Now
• ACS - (i) American Chemical Society, American Cancer Society, Association of Caribbean States, Affiliated Computer Services (NYSE ACS)
• ACTU - (i) Australian Council of Trade Unions

AD-AE

• AD - (i) Latin, Anno Domini ("In the year of our Lord")
• ADA - (i) American Dental Association / Americans with Disabilities Act (but see also the similar, but non-acronymic, Ada as in Ada programming language)
• ADC - (i) Apple Display Connector
• ADD - (i) analogue digital digital - Attention-Deficit Disorder
• ADP - (i) Adenosine diphosphate
• ADHD - (i) Attention-Deficit Hyperactivity Disorder
• ADHS - (i) attention-deficit hyperactivity syndrome
• ADL - (i) Anti-Defamation League
• ADM - (i) Archer Daniels Midland
• ADS - (a/i) Astrophysics Data System - Attention Deficit Syndrome
• ADT - (i) Atlantic Daylight Time (UTC-3 hours)
• AEF - (i) American Expeditionary Force

AF-AG

• AFAIC - (i) As far as I'm concerned
• AFAICT - (i) As far as I can tell
• AFAIK - (i) As far as I know
• AFAIR - (i) As far as I remember/recall
• AFC - (i) American Football Conference - Asian Football Confederation
• AFJ - (i) April Fool's Joke
• AFK - (i) Away from keyboard (Internet chat abbreviation)
• AFL - (i) American Federation of Labor - American Football League - Arena Football League - Australian Football League
• AG - (i) Aktiengesellschaft (German for incorporated)
• AGA - (a/i) AB Gas-accumulator ("ah-gah", Swedish company) - Advanced Graphics Architecture
• AGB - (i) Internal Nintendo initialism for Game Boy Advance.
• AGC - (i) Apollo Guidance Computer - Automatic Gain Control
• AGM - (i) Annual General Meeting
• AGP - (i) Accelerated Graphics Port

AI-AM

• AI - (i) Amnesty International - Artificial insemination - Artificial intelligence
• AIA - (i) Aerospace Industry Association
• AIC - (i) African Independent Church
• AICMFP - (i) and I claim my five pounds
• AIDS - (a) Acquired Immune Deficiency Syndrome
• AIM - (i) many, including AOL Instant Messenger; see entry
• AIPAC - (i) American Israel Public Affairs Committee
• aka - (i) also known as
• AKDT - (i) Alaska Standard Daylight Saving Time (UTC-8 hours)
• AKST - (i) Alaska Standard Time (UTC-9 hours)
• AL - Anno Lucis, the "Year of Light" in Masonic tradition. Most often seen on plaques bearing the founding dates of buildings, in years AD and years AL.
• ALAP - (a) as long/late as possible
• ALGOL - (a) Algorithmic language
• ALS - (i) Amyotrophic lateral sclerosis
• AM - (i) many, including Amplitude modulation; see entry
• AMA - (i) American Medical Association
• AMD - (i) Advanced Micro Devices (U.S. company)
• AMP - (i) Adenosine monophosphate
• AMRAAM - (a) Advanced Medium-Range Air-to-Air Missile
• AMS - (i) American Mathematical Society

AN-AR

• ANA - (a) All Nippon Airways, anti-nuclear anti-body
• ANC - (i) African National Congress
• ANSI - (a) American National Standards Institute
• ANZAC - (a) Australian and New Zealand Army Corps
• AOL - (i) America Online
• AP - (i) Associated Press - Advanced Placement
• APB - (i) All points bulletin (police jargon)
• apm - (i) Advanced Power Management
• ARSC - (i) Artic Region Supercomputing Center.

AS

• ASA - (i) Acetesalicylic acid - American Standards Association - Army Security Agency - Atlantic Southeast Airlines
• ASAP - (a) as soon as possible
• ASCAP - (a) American Society of Composers, Authors, and Publishers
• ASCC - (i) Automatic Sequence Controlled Calculator
• ASCII - (a) American Standard Code for Information Interchange
• ASDF - (i) Attack, Sustain, Decay, Release (sound envelope specification)
• ASEAN - (i) Association of Southeast Asian Nations
• ASFAR - (a) Americans for a Society Free of Age Restrictions
• ASIC - (a) Application-specific integrated circuit
• ASICS - (a) Latin, Anima Sana In Corpore Sano ("A Sound Mind in a Sound Body") (athletic shoe manufacturer)
• ASIO - (i) Australian Security Intelligence Service
• ASL - (i) American Sign Language
• ASP - (i) Active Server Pages - Application Service Provider (cf ISP)
• ASQ - (a) American Society for Quality
• ASRAAM - (a) Advanced Short-Range Air-to-Air Missile
• AST - (i) Atlantic Standard Time (UTC-4 hours)
• ASTREA - (a) Aerial support to regional enforcement agencies (sheriff's air support unit)

AT-AY

• ATAS - (a) Air-to-Air Stinger (missile)
• ATB - (i) Active Time Battle.
• ATM - (i) automated teller machine - asynchronous transfer mode - at the moment
• ATP - (i) Adenosine triphosphate
• AT&T - (i) American Telephone and Telegraph (U.S. company, aka "Ma Bell")
• ATI - (i) Allied Telesyn International, Inc.
• ATV - (i) All-Terrain Vehicle
• AUC - (i) Latin, Ab Urbe Condita ("from the founding of the city") / Anno Urbis Conditae ("in the year since the founding of the city") (of Rome) - Area Under the Curve (concentration time curve; medicine)
• AVI - (i) Audio Video Interleave
• AVO - (i) Apprehended Violence Order
• AWACS - (a) Airborne Warning and Control System
• AWD - (i) many, including all wheel drive; see entry
• AWOL - (a) Absent Without Official Leave - Absent w/o Leave (military jargon)
• AYU - (i) As Yet Unknown

• B2B - (i) Business-to-business electronic commerce
• B2C - (i) Business-to-consumer electronic commerce
• B2E - (i) Business-to-employee electronic commerce
• B&W - (i) black and white - Babcock & Wilcox - Bowers & Wilkins

BA-BC

• BALCO - (a) Bay Area Laboratory Co-operative
• BAR - (a) British American Racing - Browning Automatic Rifle - Buy-American restrictions
• BART - (a) Bay Area Rapid Transit
• BASE - (a) as in BASE jumping - Building, Antenna, Span, Earth(form)
• BASF - (i) Badische Anilin und Soda Fabrik (German chemicals company)
• BASIC - (a) Beginner's All-purpose Symbolic Instruction Code, acronym was added later, originally it was simply Basic
• BATF - (i) U.S. Bureau of Alcohol, Tobacco, and Firearms
• BB - (i) Brigitte Bardot (actress) - Boys' Brigade (Christian youth organisation)
• BBB - (i) blood-brain barrier - Better Business Bureau
• BBC - (i) British Broadcasting Corporation
• BBQ - (i) Barbeque
• BC - (i) Before Christ - Before Common era - Blind Copy (in emailers) - British Columbia - Boston College
• BCC - (i) Blind Carbon Copy
• BCCI - (i) Board of Control for Cricket in India
• BCD - (i) Binary-coded decimal
• BCE - (i) Before Common Era - British Columbia Electric - Banque Centrale Européenne
• BCER - (i) British Columbia Electric Railway
• BCPL - (i) BCPL programming language (progenitor of C)
• BCS - (i) Bowl Championship Series (US college football)

baa british airport authority

BD-BN

• BDA - (i) British Dental Association
• BDFL - (i) Benevolent Dictator For Life
• BDNF - (i) Brain-derived neurotrophic factor
• BDOS - (a) Basic disk operating system; part of CP/M
• BDU - (i) battle-dress uniform
• BFE - (i) Beyond/Butt/Bum F*****' Egypt (colloquial for "quite far away")
• BIOS - (a) basic input/output system
• BIST - (a) Built-in self-test
• BIT - (i) Bilateral Investment Treaty - Built-in test
• BJT - (i) bipolar junction transistors
• BLUI - (a/i) Body Language User Interface
• BME - (i) Biomedical Engineering
• BMI - (i) Broadcast Music Incorporated - Body mass index
• BMW - (i) Bayerische Motoren Werke / Bavarian Motor Works
• BMX - (i) Bicycle/Bike Moto(r) Cross
• BNF - (i) Backus-Naur Form (computing)
• BNS - (i) Bank of Nova Scotia
• BNSF - (i) Burlington Northern Santa Fe

BO-BR

• BO2K - (i) Back Orifice 2000
• BOAC - (i) British Overseas Airways Corporation (predecessor of British Airways)
• BOAT - (a) Byway Open to All Traffic (pronounced as 2 syllables, "Bo-At")
• BODMAS - (a) Brackets, Of, Division, Multiplication, Addition, Subtraction
• BOFH - (i) Bastard operator from hell
• BOGOF - (a) Buy one, get one free
• BOHICA - (a) Bend Over Here It Comes Again
• BOP - (i) Balance of Payments
• BOT - (i) Balance of Trade
• BP - (i) British Petroleum (today, BP doesn't officially stand for everything)
• BPM - (i) Beats Per Minute
• BRB - (i) "be right back" (Internet chat abbreviation)
• BRFSS - (i) Behavioral Risk Factor Surveillance System (a CDC health survey covering the US and US territories; pronounced "BURF us")

BS-BY

• BSA - (i) Boy Scouts of America - Birmingham Small Arms (motorcycles company)
• BSD - (i) Berkeley Software Distribution (distinct from BSoD)
• BSE - (i) Bovine Spongiform Encephalopathy, better known as Mad Cow disease
• BSL - (i) British Sign Language
• BSoD - (i) Blue screen of death (distinct from BSD)
• BSP - (i) Between-show Promotion - Binary Space Partitioning - Board Support Packages - (p) Business Sponsored
• BST - (i) Binary search tree - Blended Sales Tax - Bovine somatotropin - British Summer Time
• BT - (i) British Telecommunications plc
• BTO - (i) Built to Order
• BTU - (i) British thermal unit
• BTW - (i) By the way
• BWARS - (a) Bees, Wasps & Ants Recording Society
• BWR - (i) boiling-water reactor
• BYOB - (i) Bring your own beverages/bottle
• BYOC - (i) Bring your own computer. Play on BYOB.
• BYU - (i) Brigham Young University

CA-CD

• CAC - (i) California Association of Criminalists
• CAD - (a) Computer Aided Design - computer aided dispatch
• CAIR - (i) Council on American-Islamic Relations
• CALABARZON - (p) a region in the Philippines: Cavite, Laguna, Batangas, Rizal, Quezon (not an acronym in the strictest sense)
• CAMRA - (a) The Campaign for Real Ale
• CANDU - (p) from "Canada Deuterium Uranium", a nuclear reactor design
• CARE - (a) Cooperative for Aid and Relief Everywhere (originally C.A.R.E. - Cooperative for American Remittances to Europe)
• CAW - Canadian Auto Workers trade union
• CB - (i) citizens' band radio
• CBE - (i) Commander of the Order of the British Empire
• CBC - (i) Canadian Broadcasting Corporation - Cipher Block Chaining
• CBM - (i) many, including Canadian Baptist Ministries and Commodore Business Machines; see entry
• CBT - (i) Cognitive behavior therapy
• CC - (i) many, including carbon copy; see entry
• CCCP - (i) Cyrillic for SSSR (Union of Soviet Socialist Republics) - Central Committee of the Communist Party
• CCD - (i) charge-coupled device
• CCRAp - (a) Canadian Conservative Reform Alliance party
• CD - (i) many, including Compact disc; see entry
• CDC - (i) Centers for Disease Control and Prevention - Control Data Corporation
• CDF - (i) California Department of Forestry and Fire Protection

CE-CH

• CE - (i) [many meanings, including Christian/Common Era (cf. AD); see entry]
• CENTO - (a) Central Treaty Organization (Baghdad Pact)
• CEO - (i) Chief executive officer
• CEPT - (a/i) Conference Européenne des administration des Postes et des Télécommunications (European Conference of Postal and Telecommunications Administrations)
• CERN - (a) Centre Européen pour la Recherche Nucléaire
• CERT - (a) Computer Emergency Response Team
• cf. - (i) Latin, confer ("compare", or "see also")
• CF - Canadian Forces
• CFA - (i) Cat Fanciers' Association - Chartered financial analyst - Colour filtering array - Country Fire Authority
• CFG - (i) Context-free grammar - Control flow graph
• CFO - (i) Chief financial officer
• CFSP - (i) Common Foreign and Security Policy
• CGT - (i) Capital gains tax
• CHP - (i) California Highway Patrol

CI-CM

• CIA - (i) Central Intelligence Agency - Culinary Institute of America
• CIB - (i) Complete in box (of items on Internet auction/trading listings)
• CIBC - (i) once the Canadian Imperial Bank of Commerce
• CICS - (a) Customer Information Control System (IBM mainframe software)
• CID - (i) Criminal Investigations Department
• CIO - (i) Chief information officer - Congress of Industrial Organizations
• CIS - (i) Commonwealth of Independent States (former Soviet Union) - Canadian Interuniversity Sport
• CISB - (i) Complete in sealed box (of items on Internet auction/trading listings)
• CIWS - Close-in weapon system
• CJ - (i) Criminal Justice
• CJC - (i) Canadian Jewish Congress
• CLEC - (i) Competitive Local Exchange Carrier
• CLEMARS - (a) California Law Enforcement Mutual Aid Radio System
• CLI - (i) command line interface/interpreter
• CMHC - (i) Canada Mortgage and Housing Corporation
• CMM - (i) Capability Maturity Model
• CMOS - (i) complementary metal-oxide-semiconductor - Canadian Meteorological and Oceanographic Society
• CMR - (i) Coaxial Main Rotors (helicopter type)
• CMYK - (i) cyan magenta yellow key (colour model)

CN-CQ

• CN - (i) Canadian National
• CND - (i) Campaign for Nuclear Disarmament
• CNN - (i) Cable News Network - Cellular nonlinear network
• CNR - (i) Canadian National Railway
• CO - (i) many, including Central Office (phone company); see entry; (ii) Commanding Officer
• COO - (i) Chief Operting Officer
• c/o - (i) care of (postal code indicating temporary address change)
• COBOL (a) - Common Business-Oriented Language
• COD - (i) cash on delivery
• COLA - (a) cost of living adjustment - comp.os.linux.announce
• CONCACAF - (a) Confederation of North, Central American and Caribbean Association Football
• CONMEBOL - (p) Confederación Sudamericana de Fútbol (South American Football Confederation)
• CPA - (i) Certified Public Accountant
• COSER - (i) COoperative SERvice
• CPAC - (i) Conservative Political Action Conference - Canadian Parliamentary Affairs Channel
• CPPCC - (i) Chinese People's Political Consultative Conference
• CPR - (i) Canadian Pacific Railway - cardiopulmonary resuscitation
• CPSU - (i) Communist Party of the Soviet Union
• CPU - (i) central processing unit
• CQD - (i) come quick, distress (?)

CR-CW

• CRC - (i) Christian Reformed Church - Cyclic redundancy check - Chemical Rubber Company
• CREB - (a) Cyclic AMP-response element binding (protein)
• CREEP - (a) Committee to Re-elect the President
• CRM - (i) Customer Relationship Management
• CRT - (i) cathode ray tube - Chinese remainder theorem
• CRTC - (i) Canadian Radio-television and Telecommunications Commission
• CSA - (i) Confederate States of America - Canadian Standards Association - Canadian Space Agency - Child Support Agency - Czech Airlines - Community-supported agriculture
• CSI - (i) see entry
• CSICOP - (i) Committee for the Scientific Investigation of Claims of the Paranormal
• CSIS - (i) Canadian Security Intelligence Service - Center For Strategic & International Studies
• CSS - (i) Cascading Style Sheets - content-scrambling system - cross site scripting - Confederate States Ship
• CTO - (i) Chief technical officer
• CTSS - (i) Compatible Time-Sharing System
• CUNY - (a) City University of New York (usually pronounced "CUE-knee")
• CUPE - (i) Canadian Union of Public Employees
• CUPW - (i) Canadian Union of Postal Workers
• CV - (i) many, including curriculum vitae (resumé); see entry
• CVR - (i) Cockpit voice recorder
• CVS - (i) Concurrent Versions System
• CWC - (i) Chemical Weapons Convention

• D&D - (i) Dungeons and Dragons.

DA-DE

• DAQ - (p) Data acquisition
• DART - (a) Dublin Area Rapid Transit
• DASL - (i) DASL programming language Datapoint's Advanced Systems Language
• d/b/a - (i) doing business as
• DBE - (i) Dame Commander of the Order of the British Empire
• DC - (i) da capo - Italian Democrazia Cristiana - direct current - District of Columbia - Douglas Aircraft Company - Dublin Core - duty cycle
• DD - (i) many, including dear daughter (increasingly prevalent on social mailing lists, blogs, and bulletin boards); see entry
• DDA - (i) digital differential analyzer
• DDD - (i) digital digital digital (CD mastering) - Data Display Debugger
• DDoS - (i) distributed denial of service
• DDR - (i) Dance Dance Revolution - Deutsche Demokratische Republik (East Germany, English abbr.: GDR, qv.) - Double Data Rate
• DDS - (i) Doctor of Dental Surgery
• DDT - (i) dichloro-diphenyl-trichloroethane (insecticide) - Dynamic Debugging Tool (computing)
• DEA - (i) Drug Enforcement Agency
• DEC - (a/i) Digital Equipment Corporation - Disasters Emergency Committee - Department of Environmental Conservation
• DECT - (a) Digital European Cordless Telephone

DH-DP

• DH - (i) Designated hitter - dear husband (increasingly prevalent on social mailing lists, blogs, and bulletin boards)
• DHS - (i) Department of Homeland Security.
• DHSS - (i) Department of Health and Social Security
• DIMM - (a) Dual In-line Memory Module (computing)
• DINK - (a) Double income, no kids
• DIY - (i) do it yourself
• DMA - (i) direct memory access (computing)
• DMD - (i) Doctor of Dental Medicine
• DMT - (i) Dimethyltryptamine
• DMV - (i) Department of Motor Vehicles
• DMZ - (i) demilitarized zone
• DNA - (i) DeoxyriboNucleic Acid - Douglas Adams
• DND - (i) Do Not Disturb - Department of National Defense
• DOA - (i) Dead On Arrival - Dead or Alive
• DOI - (a) Digital Object Identifier
• DOM - (i) Document Object Model
• DOS - (a) Density of State - Disk Operating System - Denial of Service (DoS, cf. DDoS)
• DPCO - (i) double-pole change over
• DPDT - (i) double-pole double-throw
• DPRK - (i) Democratic People's Republic of Korea
• DPST - (i) double-pole single-throw

DR-DW

• DRA - (i) Democratic Republic of America
• DRAM - (a) dynamic random access memory ("dee-ram") (computing)
• DRC - (i) Democratic Republic of the Congo
• DREA - (i) Defense Research Establishment Atlantic
• DRL - (i) daytime running lights - Dorman Roberts Ltd.
• DSRV - (i) Deep Submergence Rescue Vehicle - Deaf Sports Recreation Victoria
• DS - (i) dear husband, dear daughter, dear son (increasingly prevalent on social mailing lists, blogs, and bulletin boards)
• DTE - (i) Down to earth, or Data Terminal Equipment
• DTL - (i) diode-transistor logic (electronics)
• DTRA - (i) Defence Threat Reduction Agency
• DIP - (a) dual in-line package (electronics)
• DUI - (i) Driving Under the Influence - Data Use Identifier - Data Use Institute - Davis Unified Ignition - Diving Unlimited International - Documento Único de Identidad - Documento Unico de Importación - Duke University Improv
• DVD - (i) Digital Versatile Disk (was Digital Video Disk)
• DVM - (i) Doctor of Veterinary Medicine
• DWI - (i) Driving While Intoxicated/Impaired - Dance With Intensity - Danish West Indies - Diffusion-weighted imaging - Direct water injection - Disaster Welfare Inquiry - Drinking Water Inspectorate

• E3 - (i) Electronic Entertainment Expo and other meanings, see entry

EA-EM

• EAFUS - (i) "Everything" Added to Food in the United States (FDA list)
• EBCDIC - (a/i) Extended Binary Coded Decimal Interchange Code (pronounced "eb-see-dik") (cf. BCD)
• EBE - (i) extraterrestrial biological entity
• EBW - (i) exploding bridgewire
• ECL - (i) emitter coupled logic (electronics)
• ECS - (i) Extended Chip Set (computing)
• ECT - (i) Electroconvulsive therapy
• EDS - (i) Electronic Data Systems
• EEC - (i) European Economic Community (predecessor of the EU, qv.)
• EEG - (i) Electroencephalogram
• EFF - (i) Electronic Frontier Foundation
• e.g. - (i) example gratis (Latin, roughly "for example", "for instance")
• EKG - (i) Electrocardiogram (from German, Elektrokardiogramm)
• ELF (sometimes pronounced "elf") - (i) Earth Liberation Front - Endangered Language Fund - Eritrean Liberation Front - Executable and Linkable Format - Extremely Low Frequencies
• EMF - (i) electromotive force
• EMO - (i) emergency-measures organisation
• EMP - (i) electromagnetic pulse
• EMT - (i) emergency medical technician

EN-EV

• ENE - (i) east northeast
• EPCOT - (a) Experimental Prototype Community of Tomorrow
• EPL - (i) English Premier League
• ERA - (i) earned run average - Engineering Research Associates - Equal Rights Amendment
• ERCIM - (i) European Research Consortium for Informatics and Mathematics
• ESA - (i) European Space Agency
• ESE - (i) east southeast
• ESP - (i) Extra-Sensory Perception
• ESU - (i) Emergency services unit
• ETA - (i) estimated time of arrival - Euzkadi Ta Azkatasuna
• etc - (i) latin "et cetera" (and remaining)
• ETLA - (i) Extended TLA
• EU - (i) European Union
• EULA - (i) End-User License Agreement
• EVA - (i) extra-vehicular activity

FA-FI

• FAAQ - (i) Frequently Asked and Anticipated Questions (cf. FAQ)
• FAD - (i) Flavin adenine dinucleotide
• FAO - (i) Food and Agriculture Organization
• FAQ - (a/i) Frequently Asked Questions (sometimes pronounced "fak")
• FARC - (a) Fuerzas Armadas Revolucionarias de Colombia (Revolutionary Armed Forces of Colombia)
• FASEB - (i) Federation of American Societies for Experimental Biology
• FBI - (i) Federal Bureau of Investigation
• FCC - (i) Federal Communications Commission
• FCM - (i) Fogarty's Cove Music - Federation of Canadian Municipalities
• FDA - (i) Food and Drug Administration (U.S.)
• FDR - (i) Franklin Delano Roosevelt - Flight data recorder
• FEMA - (a/i) Federal Emergency Management Agency
• FF - (i) Final Fantasy
• FFT (i) Fast Fourier Transform - Final Fantasy Tactics
• FIDE - (a) The Fédération Internationale des Échecs (World Chess Foundation)
• FIFA - (a) Fédération Internationale de Football Association (International Association Football Federation)
• FIFO - (a) First In First Out
• FIS - (a/i) Federation Internationale de Ski (International Ski Federation)
• FIU - (i) Florida International University

FL-FY

• FLAC - (a/i) Free Lossless Audio Codec.
• FLIR - (i) forward looking infrared (sensor)
• FLK - (i) Funny-Looking Kid (medical diagnosis in-joke)
• FM - (i) frequency modulation (electronics)
• FMSF - (i) False Memory Syndrome Foundation
• Fortran - (p) Formula Translator (programming language)
• FPS - (i) First person shooter (computer/video games) - frames per second (motion pictures, television, computer graphics)
• FQDN - Full Qualified Domain Name
• FSC - (a) Forest Stewardship Council (an ecological pressure group)
• FSF - (i) Free Software Foundation
• FST - (i) Finlands Svenska Television (Finland's Swedish-language television)
• FTC - (i) Federal Trade Commission
• FTL - (i) Faster Than Light
• FTP - (i) File Transfer Protocol
• FTSE - (a/i) Financial Times Stock Exchange (pronounced "footsie")
• FVF - (i) Firefox Version Format
• FUBAR - (a) Fucked (or Fouled) Up Beyond All Recognition
• FUD - (a) Fear, Uncertainty & Doubt (marketing strategy)
• FWI - (i) French West Indies
• FWIW - (i) For What It's Worth
• FYI - (i) For Your Information
• FYROM - (i) Former Yugoslav Republic of Macedonia

• G3 - (i) many, including Heckler und Koch G3; see entry
• G4 - (i) Generation Four PowerPC microprocessor
• G5 - (i) Generation Five  PowerPC microprocessor

GA-GI

• GAAR - (a) General anti-avoidance rule (see Tax evasion)
• GABA - (i) Gamma-aminobutyric acid
• GAD - (a) Generalized Anxiety Disorder
• GBE - (i) Knight/Dame Grand Cross of the Order of the British Empire
• GCD - (i) see entry
• GCF - (i) greatest common factor
• GDP - (i) gross domestic product
• GDR - (i) German Democratic Republic (cf. DDR)
• GE - (i) General Electric - Genetic Engineering (cf. GM)
• GEOS - (i) Graphical Environment Operating System
• Gestapo - (p) GEheime STAatsPOlizei ("secret state police")
• GEV - (i) Ground Effect Vehicle - Giga Electron-Volt (spelled GeV).
• GFCI - (i) ground fault circuit interrupter (aka GFI)
• GFDL - (i) GNU Free Documentation License
• GFI - (i) ground fault interrupter (aka GFCI)
• GFY - (i) Internet chat acronym, "good for you", or "go fuck yourself", depending on the context
• GHB - (i) gamma-hydroxybutyrate
• GI - (i) Galvanised Iron - General Issue - Government Issue - Gastro-intestinal
• GIF - (a) Graphics Interchange Format
• GIGO - (a) Garbage In Garbage Out
• GIMP - (a) GNU Image Manipulation Program

GL-GU

• GL - (i) Grenade Launcher - Graphics Language
• GLUT - (a/i) OpenGL Utility Toolkit.
• GLAAD - (a) Gay and Lesbian Alliance Against Defamation
• GM - (i) GameMaster (role-playing terminology) / Genetically Modified / General Motors / Guru Meditation
• GmbH - (i) Gesellschaft mit beschränkter Haftung (German, roughy "Inc" or "Ltd")
• GMO - (i) Genetically modified organism
• GMT - (i) Greenwich Mean Time
• GNOME - (a) GNU Network Object Model Environment
• GNU - (a) GNU's Not Unix
• GOMER - (a) Get Out of My Emergency Room (derogatory reference to hypochondriac patients)
• GOP - (i) Grand Old Party (United States Republican Party)
• GPG - (i) GNU Privacy Guard
• GPIB - (i) General-Purpose Instrumentation/Interface Bus
• GPL - (i) General Public License
• GPS - (i) Global Positioning System
• GRAS - (i) Generally Regarded as Safe (FDA list)
• grep - (a) (search) globally for regular expression, print (lines)
• GSOH - (i) Good sense of humour
• GST - (i) Goods and Services Tax (in Canada, Australia, etc
• GT - (i) Gran Turismo - Grand Touring
• GUI - (a) Graphical User Interface (pronounced goo-ey)
• Gulag - (p) Glavnoe Upravlenie ispravitel'no-trudovykh LAGerei
• GUT - (i) grand unification theory

HA-HM

• HAI - (a) Human Awareness Institute
• HALO - (a) High Altitude Low Opening (type of a parachute jump)
• HCF - (i) highest common factor
• HDD - (i) hard disk drive - high-density disk
• HEPA - (i) High-efficiency particulate air (filter)
• Hg - (i) Mercury (element)
• Hird - (a) Hurd of interfaces representing depth (cf. HURD)
• HIV - (i) Human Immunodeficiency Virus
• HKS - (i) hyperkinetic syndrome
• HLA - (i) Human leukocyte antigen - High level architecture
• HLL - (i) high-level language
• HMCE - (i) Her Majesty's Customs and Excise
• HMCS - (i) Her/His Majesty's Canadian Ship
• HMO - (i) Health Management Organization
• HMP - (i) Her/His Majesty's Prison
• HMS - (i) Her/His Majesty's Ship (see Royal Navy)
• HMSO - (i) Her/His Majesty's Stationery Office
• HMV - (i) His Master's Voice

HP-HW

• HP - (i) Hewlett-Packard - horse power
• HP-GL - (i) Hewlett-Packard Graphics Language
• HP-IB - (i) Hewlett-Packard Instrument/Interface Bus (first implementation of GP-IB, later standardised and now known as IEEE-488)
• HP-IL - (i) Hewlett-Packard Interface Loop (serial bus used with some HP calculators and computers, notably the HP-41 and HP-71 series)
• HPV - (i) Human papilloma virus
• HQ - (i) Headquarters
• HRH - (i) Her/His Royal Highness
• HSS - (i) High-Speed Steel
• HST - (i) see entry
• HSV - (i) herpes simplex virus - hue saturation value (colour model)
• HTML - (i) Hypertext Markup Language
• HURD - (a) Hird of Unix-Replacing Daemons (cf. Hird)
• HVP - (i) hydrolized vegetable protein - HarborView Properties - High Vacuum Process
• HW - (i) hardware

IA-ID

• IAAF - (i) International Association of Athletics Federations
• IAAL - (i) I am a lawyer
• IAEA - (i) International Atomic Energy Agency
• IAF - {i} Industrial Areas Foundation
• IAI - (i) International African Institute - Israel Aircraft Industries
• IANA - (i) Internet Assigned Numbers Authority
• IANAL - (i) I am not a lawyer
• IATA - (a/i) International Air Transport Association
• ICAO - (i) International Civil Aviation Organization
• ICBM - (i) intercontinental ballistic missile
• ICBN - (i) International Code of Botanical Nomenclature
• ICC - (i) International Criminal Court
• ICD - (i) Implantable cardioverter-defibrillator - International Classification of Diseases
• ICHTHYS - (a) Iesous Christos, Theou Yios, Soter (Greek for "Jesus Christ, Son of God, Savior")
• ICP - (i) Insane Clown Posse - inductively coupled plasma
• ICZN - (i) International Code of Zoological Nomenclature
• IDF - (i) Israel Defence Forces

IE-IQ

• i.e. - (i) id est (Latin, roughly "that is")
• IE - Internet Explorer - Indo-European
• IED - (i) Improvised Explosive Device
• IEEE - (i) Institute of Electrical and Electronics Engineers (pronounced "I triple-E")
• IETF - (i) Internet Engineering Task Force
• IFO - (i) Identified flying object
• IHR - (i) Institute for Historical Review
• IIRC - (i) If I recall/remember correctly
• IIT - (i) Indian Institutes of Technology - Illinois Institute of Technology - Indiana Institute of Technology
• ILC - (i) International Law Commission
• ILO - (i) International Labour Organisation
• IMF - (i) International Monetary Fund
• IMHO - (i) In My Humble Opinion
• IMO - (i) International Maritime Organization - In My Opinion
• IMRI - (i) Industrial Membrane Research Institute - Information Management Research Institute - International Market Research Information - Institut pour le Management de la Recherche et de l'Innovation - intraoperative magnetic resonance imaging
• INC - (i) Iraqi National Congress
• INLA - (i) Irish National Liberation Army
• INRI - (a/i) Iesus Nazarenus Rex Iudæorum (Latin, "Jesus of Nazareth, King of the Jews")
• IP - (i) Intellectual property - Internet Protocol
• IPN - (i) Instytut Pamieci Narodowej (Institute for National Memory)
• IQ - (i) Intelligence Quotient

IR-IU

• IR - (i) Infrared
• IRA - (i) Individual Retirement Account (legally, Individual Retirement Arrangement) - Irish Republican Army
• IRBM - (i) intermediate Range Ballistic Missile
• IRC - (i) International reply coupon
• IRC - (i) Internet relay chat
• IRO - (i) International Refugee Organisation
• IRS - (i) Internal Revenue Service
• ISA - (i) Individual Savings Account - industry standard architecture - Instruction Set Architecture - International Seabed Authority
• ISAF - (a) International Sailing Federation - International Security Assistance Force
• ISCII - (a) Indian Standard Code for Information Interchange
• ISO - (i) In search of - International Organization for Standardization
• IT - (i) Information Technology
• ITN - (i) Independent Television News (British TV news company)
• ITS - (i) Incompatible Time-sharing System
• ITT - (i) International Telephone and Telegraph (US company)
• ITU - (i) International Telecommunication Union
• IUPAC - (a) International Union of Pure and Applied Chemistry (pronounced "eye-yoo-pac"
• IWW - (i) Industrial Workers of the World

• JAG - (a) Judge Advocate General (US military lawyers)
• JAL - (a) Japan Airlines
• JAMA - (i) Journal of the American Medical Association
• JATO - (a) Jet Assisted Takeoff Unit
• JCS - (i) Joint Chiefs of Staff
• JDL - (i) Jewish Defense League
• Jeb Bush - (a) John Ellis Bush
• Jeb Stuart - (a) James Ewell Brown (Stuart's given names)
• JFK - (i) John Fitzgerald Kennedy or the airport named after him.
• JPEG - (a) Joint Photographic Experts Group
• JRA - (i) Japanese Red Army
• JW - (i) Jehovah's Witnesses

• KARNAC - (a) Knowledge Aided Retrieval in Activity Context
• KBE - (i) Knight Commander of the Order of the British Empire
• KCK - (i) Kansas City, Kansas
• KCMO - (p) Kansas City, Missouri (pronounced "K-C-Moe")
• KFC - (i) Kentucky Fried Chicken
• KGB - (i) Komitet Gosudarstvennoy Bezopasnosti (Committee for State Security - Soviet Intelligence Service)
• KIA - (i) Killed In Action
• KISS - (a) Keep it simple stupid
• KKK - (i) Ku Klux Klan
• KLM - (i) Koninklijke Luchtvaart Maatschappij (Royal Dutch Airlines)
• KMFDM - (i) Kein mitleid für die mehrheit, or "no pity for the majority" (band)

LA-LI

• LA - (i) Los Angeles
• LACMA - (i) Los Angeles County Museum of Art
• LAN - (a) Local Area Network
• LANL - (i) Los Alamos National Laboratory
• LARC - (a) Livermore Advanced Research Computer (cf. LLNL)
• Laser - (a) Light Amplification by Stimulated Emission of Radiation (cf. Maser)
• LATA - (i) Local Access Transport Area
• LabVIEW - (p) Laboratory Virtual Instrumentation Engineering Workbench
• LBGT - (i) Lesbian, Gay, Bisexual, Transgender
• LBJ - (i) Lyndon Baines Johnson - Lady Bird Johnson - Little Beagle Johnson (their dog) - Lightbulb joke
• LBNL - (i) Lawrence Berkeley National Laboratory
• LBS - Location-Based Services
• LBW - (i) leg before wicket
• LCD - (i) liquid crystal display
• LCM - (i) least common multiple
• LDAP - (a/i) Lightweight Directory Access Protocol (pronounced "ell-dap")
• LDS - (i) Latter Day Saint - Liberal Democracy of Slovenia
• LEC - (i) Local Exchange Carrier
• LED - (i) Light Emitting Diode
• LGB - (i) Lesbian, Gay, Bisexual
• LGM - (i) little green men
• LIFO - (a) Last in, first out

LL-LV

• LLC - (i) limited liability company
• LLNL - (i) Lawrence Livermore National Laboratory
• LLP - (i) limited liability partnership
• LMAO - (i) Laughing my a** off.
• LMS - (i) London Mathematical Society
• LNG - (i) liquefied natural gas
• LOL