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Author: William A. Stein
William Stein's Acronym list

Acronym list

William A. Stein

I found a list of acronyms on the web, and have steadily added to it. If you think of any good ones that aren't listed below please send me an email.
ACLSC = Advanced Cardiac Life Support Certified
AHEC = Area Health Education Center
ASCP = American Society of Clinical Pathologists
BC = Board Certified
CDE = Certified Diabetes Educator
CEMT = Certified Emergency Medical Technician
CFCS = Certified in Family and Consumer Sciences
CHES = Certified Health Education Specialist
CLC = Certified Life Style Counselor
FCS = Family and Consumer Science(s)
FNP = Family Nurse Practitioner
LCPC = Licensed Clinical Professional Counselor
LD = Licensed Dietitian
LGP = Licensed Group Psychotherapist
LMNT = Licensed Medical Nutrition Therapist
LP = Licensed Psychologist
MSc = Master of Science
MT = Medical Technologist
NET = Nutrition Education and Training
NP = Nurse Practitioner
PA-C = Physician's Assistant—Certified
WIC Program = Women, Infants, and Children Program

2D	2-Dimensional
3D	3-Dimensional
3M	Minnesota Mining and Manufacturing
4GL	Fourth Generation Language
4H	Head, Heart, Hands, Health
4WD	Four wheel Drive (see also FWD)
A	Aftermath
AA	Affirmative Action committee
AA	Alcoholics Anonymous
AA	Antiaircraft Artillery
AA	Associate in Accounting
A&A	Astronomy and Astrophysics [Space]
AA	Automobile Association [England]
AAA	American Automobile Association
AAAL	American Academy of Arts and Letters
AAAS	American Association for the Advancement of Science
AAII	American Association of Individual Investors
AAMSI	American Association for Medical Systems Informatics
AAO	Anglo-Australian Observatory [Space]
AAP	Affirmative Action Program
AARC	Anglo-American Cataloging Rules
AARN	Australian Academic Research Network [Networking]
AARP	American Association of Retired Persons
AAS	American Astronomical Society [Space]
AAVSO	American Association of Variable Star Observers [Space]
AB	ABle seaman
ABA	American Bar Association
ABA	American Basketball Association
ABA	American Booksellers Association
ABBR	ABBReviation
ABC	American Broadcasting Company [Corporate name]
AC	Alternating Current (ac, see also DC)
AC	Ante Christum (before Christ)
AC	Ante Cibum (before meals)
ACAA	Agricultural Conservation and Adjustment Administration
ACAWS	Advisory, Caution, And Warning System
ACBL	American Contract Bridge League
ACC	Argonne Code Center
ACCS	Army Command and Control System
ACD	Automatic Call Distributor [Telephony]
ACE	Advanced Composition Explorer [Space]
ACE	Advanced Computing Environments [Corporate name]
ACE	Automatic Calibration and Equalization
ACHEFT	Automated ClearingHouse Electronic Funds Transfer
ACK	ACKnowledge
ACL	Advanced Cmos Logic
ACLU	American Civil Liberties Union
ACM	Association for Computing Machinery
ACRV	Assured Crew Return Vehicle (or) Astronaut Crew Rescue Vehicle [Space]
ACS	Advanced Communications System
ACSE	Association Control Service Entity (ISO/CCITT layer 7)
ACT	Action for Children's Television (in Cambridge, MA)
ACT	American Conservatory Theater
ACTS	Advanced Communications Technology Satellite
ACTS	Automatic Coin Telephone Service [Telephony]
ACU	Alarm Control Unit
ACU	Automatic Call Unit [Telephony]
ACW	Alternating Continuous Waves
AD	After Date
A/D	Analog to Digital converter (see ADC)
AD	Anno Domini (in the year of our Lord)
AD	Application Development
Ad Astra	To the stars [Latin, Space]
ADAP	Alzheimer's disease-associated protein
ADAP	American Discount Auto Parts [Corporate name]
ADB	A DeBugger
ADB	Apple Desktop Bus
ADC	Analog to Digital Converter
ADCI	Automatic Display Call Indicator 
AD&D	Advanced Dungeons & Dragons
ADF	Automatic Direction Finder
ADP	Adenosine Di-Phosphate
ADP	Administrative Data Processing
ADP	Advanced Data Processing
ADPCM	Pulse Code Modulation with Adaptive Quantization
ADS	Application Development System
ADSR	Attack Decay Sustain Release
ADT	Abstract Data Type
ADT	Atlantic Daylight Time
AE	Application Execution
AEA	American Electronics Association
AEC	Atomic Energy Commission
AEF	American Expeditionary Force (see BEF)
AEGIS	Advanced Electronic Guidance and Instrumentation System
AF	Adventures in Fantasy
AF	Air Force
AF	Audio Frequency
AFADS	Automatic Force Adjustment Data System 
AFATDS	Advanced Field Artillery Tactical Data System
AFB	Air Force Base
AFC	American Football Conference
AFC	Automatic Flight Control
AFC	Automatic Frequency Control
AFCAC	Air Force Computer Acquisition Center
AFCC	Air Force Communications Command
AFGE	American Federation of Government Employees
AFIPS	American Federation of Information Processing Societies
AFL	American Federation of Labor
AFL	American Football League
AFLCIO	American Federation of Labor and Congress of Industrial Organizations
AFNOR	Association Francaise de NORmalization
AFP	Appletalk Filing Protocol
AFS	Andrew File System
AFSC	Air Force Systems Command
AFSCME	American Federation of State, County and Municipal Employees
AFTRA	American Federation of Television and Radio Artists
AG	Adjutant General
AG	Arcade Game
AG	Attorney General
AGCT	Army General Classification Test
AGN	Active Galactic Nucleus [Space]
AHL	American Hockey League
AHQ	Air HeadQuarters
AI	Artificial Intelligence
AIAA	American Institute of Aeronautics and Astronautics [Space]
AIC	Automatic Intercept Center 
AID	Agency for International Development
AIDDE	Ames' Interactive Dynamic Display Editor
AIDS	Acquired ImmunoDeficiency Syndrome
AIOD	Automatic Identification Outward Dialing 
AIS	Automatic Intercept System
AIX	Advanced Interactive eXecutive (IBM's name for UNIX)
AJ	Astronomical Journal [Space]
AK	Alaska
AKA	Also Known As
AL	Alabama [US state postal designation]
AL	American League (baseball)
ALA	American Library Association
ALA	Automobile Legal Association
ALBM	Air-to-Land Ballistic Missile
ALC	Automatic Load Control
ALGOL	ALGOrithmic Language
ALIT	Automatic Line Insulation Testing [Telephony]
ALPO	Association of Lunar and Planetary Observers [Space]
ALS	Advanced Launch System [Space]
ALU	Arithmetic Logic Unit
A&M	Agricultural and Mechanical
AM	Amplitude Modulation
AM	Ante Meridiem (before noon)
AMA	American Medical Association
AMA	Automatic Message Accounting [Telephony]
AMARC	Automatic Message Accounting Recording Center 
AMBA	Association of Master of Business Administration
AMC	Albany Medical College
AMC	American Motors Corporation(?) [Corporate name]
AMC	Appalachian Mountain Club
AMD	Advanced Micro Devices [Corporate name]
AMEX	AMerican EXpress [Corporate name]
AMI	Alternate Mark Inversion (see also NRZ, NRZI, B8ZS)
AMORC	Ancient Mystic Order Rosae Crucis
AMP	Adenosine MonoPhosphate
AMPAS	Academy of Motion Picture Arts and Sciences
AMPAS	Acedemy of Motion Picture Arts and Sciences
AMRAAM	Advanced Medium Range Air-To-Air Missile
AMROC	American Rocket Company [Space]
AMSAT	radio AMateur SATellite corp.
AMU	Atomic Mass Unit
AMVET	AMerican VETeran
ANA	American Nurses Association
ANAC	Automatic Number Announcemnt Circuit [Telephony]
ANC	All Number Calling [Telephony]
ANC	Army Nurse Corps
ANDF	Architecture-Neural Distribution Format
ANF	Automatic Number Forwarding [Telephony]
ANG	Air National Guard
ANI	Automatic Number Identification (see also: CLID) [Telephony]
ANL	Argonne National Laboratory
ANOVA	ANalysis Of VAriance
ANPA	American Newspaper Publishers Association
ANSI	American National Standards Institute
ANZUS	Australia, New Zealand, United States
AO	Account Of
AOA	Abort Once Around [NASA, Shuttle]
AOA	Abort Once Around (Shuttle abort plan) [Space]
AOL	Absent Over Leave (see AWOL)
AOS	Academic Operating System
AOS	Alternate Operator Service [Telephony]
A/P	Accounts Payable
AP	Additional Premium
AP	All Points
AP	Associated Press [Corporate name]
APA	All Points Addressable
APA	American Psychological Association
APB	All Points Bulletin
APDA	Apple Programmers and Developers Association
API	Application Programming Interface
APICS	American Production and Inventory Control Society
Ap.J	Astrophysical Journal [Space]
APL	A Programming Language
APL	acute promyelocytic leukemia [Disease]
APO	Alpha Phi Omega, service fraternity
APO	Army Post Office
APP	Applications Portability Profile
APPC	Advanced Peer-to-Peer Communications
APR	Annual Percentage Rate (as in loan interest)
APSE	Ada Programming Support Environment
APU	Auxiliary Power Unit [Space]
AQ	Accumulator-Quotient register
A/R	Accounts Receivable
AR	Address Register
AR	Arkansas
ARC	AIDS-related complex
ARC	American Red Cross
ARC	Ames Research Center (NASA) [Space]
ARCNET	Attached Resource Computer local area NETwork
ARO	After Receipt of Order
ARP	Address Resolution Protocol
ARPA	Advanced Research Projects Agency (of the DoD, see DARPA)
ARRL	Amateur Radio Relay League
ARV	American Revised Version
AS	Anglo-Saxon
ASA	Acetyl Salicylic Acid
ASAP	As Soon As Possible
ASC	Accredited Standards Committee
ASCAP	American Society of Composers, Authors, and Publishers
ASCC	Automatic Sequence-Controlled Calculator
ASCII	American Standard Code for Information Interchange
ASDIC	Anti-Submarine Detection Investigation Committee (British for sonar)
ASDSP	Application-Specific Digital Signal Processor
ASG	Automated Sciences Group
ASHRAE	Amer. Soc. of Heating, Refrigerating and Air-cond. Engineers, inc.
ASIC	Application Specific Integrated Circuit
ASME	American Society of Mechanical Engineers
ASN	Abstract Syntax Notation One (ISO/CCITT ASN.1)
ASP	Aggregated Switch Procurement
ASRM	Advanced Solid Rocket Motor [Space]
ASSR	Autonomous Soviet Socialist Republic
AST	Atlantic Standard Time
ASV	American Standard Version
AT	Atlantic Time
ATA	Automatic Trouble Analysis 
ATACC	Advanced Tactical Air Command Central
ATB	Advanced Technology Bomber (stealth bomber)
ATC	Air Traffic Control
ATDRS	Advanced Tracking and Data Relay Satellite [Space]
ATF     Dept. of Alcohol Tobacco and Firearms  
ATF	Advanced Technology Fighter
ATIS	Atherton Tools Interface Specification
ATLAS	Atmospheric Laboratory for Applications and Science [Space]
ATM	Amateur Telescope Maker [Space]
ATM	Asynchronous Transfer Mode
ATM	Automatic Teller Machine
ATO	Abort To Orbit [NASA, Shuttle]
ATO	Abort To Orbit (Shuttle abort plan) [Space]
ATOMS	AT&t Optimized Materials Simulator
ATP	Adenosine TriPhosphate
ATPCO	Airline Tariff Publishing COmpany
AT&T	American Telephone & Telegraph [Corporate name]
ATT	American Telephone & Telegraph (normally written AT&T when seperate)
ATTIS	American Telephone and Telegraph Information Systems [AT&T] (Division)
ATV	All Terrain Vehicle
AU	Astronomical Unit (93,000,000 miles) [Space]
AU	Astronomical Unit [Space]
AUI	Attachment Universal Interface
AURA	Association of Universities for Research in Astronomy [Space]
AUS	Army of the United States
AUTODIN AUTOmatic DIgital Network
AUTOVON AUTOmatic VOice Network
AV	AudioVisual
AVLIS	Atomic Vapor Laser Isotope Separation
AWACS	Airborne Warnings And Control Systems
AWEA	American Wind Energy Association
AWK	al Aho, peter Weinberger, brian Kernighan (pattern scanning language)
AWOL	Absent WithOut Leave (also Absent Without Official Leave) (see AOL)
AW&ST	Aviation Week and Space Technology (a.k.a. AvLeak) [Space]
AXAF	Advanced X-ray Astrophysics Facility [Space]
AZ	Arizona
B	Book
B8ZS	Binary 8 Zero Substitution (see also NRZ, NRZI, AMI)
BA	Bachelor of Arts
BACH	Business Alliance for Commerce in Hemp
BAFO	Best And Final Offer
BARRNet Bay Area Regional Research Network (SF Bay Area)
BASIC	Beginner's All-purpose Symbolic Instruction Code
BATSE	Burst And Transient Source Experiment (on GRO) [Space]
BB	Bases on Balls
BB	Best of Breed
BB	Bunnies and Burrows
BBA	Bachelor of Business Administration
BBB	Better Business Bureau
BBC	British Broadcasting Corporation
BBL	Barrel
BBN	Bolt, Beranek, and Newman, Inc. [Corporate name]
BBXRT	Broad-Band X-Ray Telescope (ASTRO package) [Space]
BC	Battlecars
BC	Before Christ
BC	British Columbia
BC/BS	Blue Cross/Blue Shield
BCD	Bad Conduct Discharge
BCD	Binary Coded Decimal
BCDIC	Binary Coded Decimal Interchange Code
BCE	Before the Common Era (substitute for BC)
BCNU	Be Seeing You [Net jargon]
BCP	Byte Controlled Protocols
BCPL	Basic Combined Programming Language
BCS	Bachelor of Commercial Science
BCS	Binary Compatibility Standard
BCS	Boston Computer Society
BCS	British Computer Society
BD	Bachelor of Divinity
BD	Bank Draft
BD	Bills Discounted
BD&D	Basic Dungeons & Dragons
BDF	Binary Distribution Format
BDT	Billing Data Transmitter
BE	Bill of Exchange
BEF	British Expeditionary Force (see AEF)
BELCORE BELL COmmunications REsearch
BEM	Bug Eyed Monster
BEM	Bug-Eyed Monster [Space]
BENELUX BElgium, NEtherlands, and LUXembourg
BER	Bit Error Rate
BERT	Bit Error Rate Test
BEST	Borland Enhanced Support and Training
BF	Brought Forward
BFA	Bachelor of Fine Arts
BFD	Bristol (RI) Fire Department (probably typical of any town starting "B")
BH	Black Hole [Space]
BH	Boot Hill
BHP	Brake HorsePower
BICS	Building Industry Consulting Services [Telephony]
BID	Bis In Die (twice a day)
BIMA	Berkeley Illinois Maryland Array [Space]
BIOS	Basic Input Output System
BIS	Business Information System
BISDN	Broadband ISDN (q.v.) [Telephony]
BiSync	Binary Synchronous Communications (BSC is preferred) [IBM]
Bit	BInary digiT
BITNET	Because It's Time Network
BLAST	BLocked ASynchronous Transmission
BLERT	BLock Error Rate Test
BLF	Busy Lamp Field [Telephony]
BLT	Bacon, Lettuce, and Tomato (sandwich)
BLT	BLock Transfer [Instruction]
BLT	Branch Less Than [Instruction]
BM	Basal Metabolism
BM	Bowel Movement
BMA	Bank Marketing Association
BMEWS	Ballistic Missile Early Warning
BMO	Ballistic Missile Office
BMOC	Big Man On Campus
BMR	Basal Metabolism Rate
BNC	Bayonet Neill Concelman (connector) [Electronics] (see also TNC)
BNF	Bachus-Naur Form
BO	Body Odor
BO	Branch Office
BO	Buyer's Option
BOC	Bell Operating Company
BOD	Board Of Directors
BOF	Birds Of a Feather
BOM	Bill Of Materials
BOOTP	Bootstrap Protocol [Internet]
BOQ	Bachelor Officers' Quarters
BOS	Business Office Supervisor
BOSIX	Biin Open System Interface eXtension
BP	Blood Pressure
BP	British Petroleum
BP	British Pharmacopoeia
BPI	Bits Per Inch
BPL	Boston Public Library
BPL	Branch if PLus [Instruction]
BPOE	Benevolent and Protective Order of Elks
BPS	Bits Per Second
BR	Bills Receivable
BR	British Rail
BRA	Boston Redevelopment Authority
BRI	Basic Rate Interface (ISDN) [Telephony]
BRIEF	Basic Reconfigurable Interactive Editing Facility
BRL	army Ballistic Research Laboratory
BRS	Bibliographic Retrieval Service
BS	Bachelor of Science
BS	Bill of Sale
BSA	Birmingham Small Arms
BSA	Boy Scouts of America
BSc	Bachelor of SCience
BSC	Binary Synchronous Communications (also sometimes BiSync) [IBM]
BSD	Berkeley Software Distribution
BSN	Bachelor of Science in Nursing
BSS	Block Started by Symbol
BSTJ	Bell System Technical Journal
BT	British Telecom
BTAM	Basic Telecommunications Access Method [IBM]
BThU	British Thermal Unit (BTU {q.v.} is preferred)
BTL	Bell Telephone Laboratories
BTO	Bachman Turner Overdrive
BTU	British Thermal Unit
BTW	By The Way [Net jargon]
BU	Boston University
BUF	B-52 bomber ("Big Ugly Fellow") [USAF]
BV	Blessed Virgin
BWI	Baltimore-Washington International (airport)
BWI	British West Indies
BX	Base eXchange (see also PX)
c	centi- (metric 1/100)
C	programming language (successor to B, which was based on BCPL)
CA	California
CA	Chartered Accountant
CA	Chief Accountant
CA	Chronological Age
CA	Collision Avoidance (as in CSMA/CA (q.v.))
CAB	Civil Aeronautics Board
CACM	Communications of the Association for Computing Machinery
CAD	Computer Aided Design (sometimes seen as CAD/CAM)
CAD	Computer Aided Dispatching
CAE	Common Applications Environment
CAE	Computer Aided Engineering
CAI	Computer Aided Instruction
CAIS	Common Apse Interface Specification
CALS	Computer-aided Acquisition and Logistics Support
CAM	Computer Aided Management
CAM	Computer Aided Manufacturing (sometimes seen as CAD/CAM)
CAM	Content Addressable Memory
CAMA	Centralized Automatic Message Accounting [Telephony]
CAMP	Campaign Against Marijuana Planting
CAP	Civil Air Patrol
CAP	Columbia Appletalk Package
CAR	Contents of the Address part of the Register (LISP)
CARE	Committee on American Relief in Europe
CARP	California Air Resources Board
CASE	Computer Aided Software Engineering
CASSIS	Classification and Search Support Information System
CAT	Computer-Aided Tomography
CATIS	Common Applications and Tools Integration Services
CATV	Common Antenna TeleVision
CATV	Community Antenna TeleVision
CAVU	Ceiling And Visibility Unlimited
CB	Citizens Band radio
CBC	Canadian Broadcasting Corporation
CBD	Cash Before Delivery
CBD	Commerce Business Daily
CBEMA	Computer & Business Equipment Manufacturers Association
CBR	Chemical, Biological, Radiological warfare
CBS	Columbia Broadcasting System [Corporate name]
CBW	Chemical and Biological Warfare
CC	C (language) Compiler
CC	Carbon Copy
CCA	Computer Corporation of America [Corporate name]
CCAFS	Cape Canaveral Air Force Station [Space]
CCC	Canadian Committee on Cataloging
CCC	Civil(ian) Conservation Corps
CCC	Command, Control, and Communications (sometimes C^3 or C3)
CCC	Concourse Computer Center [MIT]
CCCCM	CCC CounterMeasures (sometimes C^3CM)
CCCI	Command, Control, Communications, and Intelligence
C4RSI	Command, Control, communications, Computers, Reconnaissance, Surveillance, and Intelligence
CCD	Charge Coupled Device (see CID)
CCD	Charge-Coupled Device [Space]
CCDS	Centers for the Commercial Development of Space [Space]
CCF	Hundred Cubic Feet
CCI	Computer Carrier Interrupt
CCI	Computer Consoles, Incorporated
CCIP	Continuously Computed Impact Point
CCIRN	Coordinating Committee for Intercontinental Research Networking
CCIS	Common Channel Interoffice Signaling [Telephony]
CCITT	Comite' Consultatif International Telegraphique et Telephonique
CCITT	Consultative Committee on International Telephony and Telegraphy
CCITT	International Telegraph and Telephone Consultative Committee
CCR	Commitment, Concurrency, and Recovery
CCR	Creedence Clearwater Revival [Music]
CCRI	Community College of Rhode Island [Corporate name]
CCRP	Continuously Computed Release Point
CCS	Hundred Call Seconds [Telephony]
CCS7	Common Channel Signalling (version #7) [Telephony, AT&T]
CCSA	Common Control Switching Arrangement [Telephony]
CCTA	Central Computer and Telecommunications Agency
CCTV	Closed Circuit TeleVision
CD	Carrier Detect (properly DCD (q.v.)) (EIA RS-232-C)
CD	Certificate of Deposit
CD	Civil Defense
CD	Collision Detection (as in CSMA/CD (q.v.))
CD	Compact Disk
CDA	Call Data Accumulator
CDA	Compound Documents Architecture
CDC	Centers for Disease Control
CDC	Control Data Corporation, Inc. [Corporate name]
CDEV	Control panel DEVice
CDIAC	Carbon Dioxide Information Analysis Center
CDO	Community Dial Office
CDR	CommanDeR
CDR	Contents of the Decrement part of the Register (LISP)
CD-ROM	Compact Disk Read Only Memory
CD-ROM	Compact Disk Read-Only Memory [Space]
CDSF	Commercially Developed Space Facility
CDT	Central Daylight Time
CDU	Control Display Unit
CE	Chemical Engineer
CE	Civil Engineer
CE	Common Era (substitute for AD)
CE	Corps of Engineers
CE	Customer Engineer (see also FE, SE)
CEA	Commissariat a l'Energie Atomique (Frenc Atomic Energy Commision)
CEA	Council of Economic Advisors
CEA	County Education Authority
CEC	Commission of the European Communities
CED	Committee for Economic Development
CELSS	Controlled Ecological Life Support System [Space]
CENS	Centre d'Etudes Nucleaires de Seclay
CENTO	CENtral Treaty Organization
CEO	Chief Executive Officer
CERFnet California Education and Research Federation Network
CERN	European Organization for Nuclear Research
CERN	organisation (formerly Conseil) Europeenne pour la Recherche Nucleaires
CERT	Computer Emergency Response Team
CEVI	Common Equipment Voltage Indicator
CF	Carry Forward
CF	Coin First (payphone) [Telephony]
CF	Cystic Fibrosis [Disease]
CFA	Center For Astrophysics [Space]
CFC	Chloro-FluoroCarbon [Chemical]
CFC	Combined Federal Campaign
CFD	Computational Fluid Dynamics
CFHT	Canada-France-Hawaii Telescope [Space]
CFI	Cost, Freight, and Insurance
CFL	Canadian Football League
CFO	Chief Financial Officer
CG	Coast Guard
CG	Commanding General
CGA	Color Graphics Adapter
CGCT	Compagnie Generale de Constructions Telephoniques
CG&E	Cincinnati Gas & Electric
CGE	Compagnie Generale d'Electricite
CH	Cardboard Heroes
CH	ClearingHouse
CH	CourtHouse
CH	Customs House
CHA	Champions
CHAP	CHAnnel Processor
CHARA	Center for High Angular Resolution Astronomy [Space]
CHI	Chill:	Adventures into the Unknown
CHOTS	Corporate Headquarters Office Technology System
CHP	California Highway Patrol
CI	Cubic Inches
CIA	Central Intelligence Agency [US Government]
CIA	Culinary Institute of America (Hyde Park, NY)
CIC	Carrier Identification Codes [Telephony] (10XXX codes)
CIC	Committee on Institutional Cooperation
CIC	Coordination and Information Center [CSNet]
CICA	Competition in Contracting Act
CICS	Customer Information Control System [IBM]
CID	Caller ID [Telephony] (see also: CLID, ANI)
CID	Central Institute for the Deaf
CID	Charge Injection Device (see CCD)
CID	Computer Integrated Design
CIDIN	Common Icao Data Interchange Network
CIM	Computer Integrated Manufacturing
CIO	Chief Information Officer
CIRRIS	Cryogenic InfraRed Radiance Instrument for Shuttle [Space]
CISC	Complex Instruction Set Computer
Cislunar	The space between the Earth and the Moon
CIT	California Institute of Technology
CIT	Case Institute of Technology (part of CWRU, Cleveland, OH)
CIT	Circumstellar Imaging Telescope [Space]
CLASP	Comprehensive Logistics Automated Support Program
CLASS	Custom Local Area Signaling Service [Telephony]
CLI	Command Line Interpreter
CLID	Calling Line ID [Telephony] (see also: CID, ANI)
CLNP	Connectionless-mode Network Protocol
CLNS	Connectionless-mode Network Service
CLR	Combined Line and Recording
CLRC	Circuit Layout Record Card
CLU	Chartered Life Underwriter
CLUT	Color LookUp Table
cm	centimeters
CM	Command Module (Apollo spacecraft) [Space]
CM	Congregation of the Mission
CMC	Communication Machinery Corp.
CMD	Centralized Message Distribution
CMIP	Common Management Information Protocol
CMIS	Common Management Information Services
CML	Current Model Logic
CMMU	Cache/Memory Management Unit
CMOS	Complementary Metal Oxide Semiconductor (see MOS)
CMOT	Common Management Information Services and Protocol Over TCP/IP
CMRR	Common Mode Rejection Ratio
CMS	Circuit Maintenance System
CMSgt	Chief Master Sergeant
CMU	Carnegie-Mellon University
CMYK	Cyan, Magenta, Yellow, blacK
CN	Canadian National [Corporate name, Railroading]
CN/A	Customer Name / Address [Telephony]
CNI	Common Network Interface [Telephony, AT&T] (Department of AT&T)
CNN	Cable News Network
CNO	Carbon-Nitrogen-Oxygen [Space]
CNO	Chief of Naval Operations
CNR	Canadian National Railways
CNR	Carrier to Noise Ratio
CNRI	Corporation for National Research Initiatives
CNRS	Centre National de la Recherche Scientifique (French National Center for Scientific Research)
CNS	Central Nervous System
CNSR	Comet Nucleus Sample Return [Space]
CO	Cash Order
CO	Central Office [Telephony]
CO	Colorado
CO	Commanding Officer
CO	Conscientious Objector
C/O	in Care Of
COB	Close Of Business
COBE	COsmic Background Explorer [Space]
COBOL	COmmon Business Oriented Language
COC	Call of Cthulhu
COCOT	Customer Owned, Coin Operated Telephone [Telephony]
COD	Collect On Delivery; Cash On Delivery
COER	Central Office Equipment Report
COLA	Cost-Of-Living Allowance
COM	Computer Output (on) Microfiche
COM	Computer Output (on) Microfilm
COMAS	Central Office Maintenance and Administration System
COMM	Communications
COMPACT COMmercial Product ACquisition Team
COMPTEL COMPton TELescope (on GRO) [Space]
COMSAT	Communications Satellite [Space]
CONACYT Consejo Nacional de Cienca Y Tecnologia (Mexican National Council of Science and Technology)
CONS	Connection-Oriented Networking Service
CONS	Connection-Oriented Networking Session
CORE	COntrolled Requirement Expression
CORN	COmputer Resource Nucleus
COS	Corporation for Open Systems
COSINE	Cooperation for Open Systems Interconnection Networking in Europe
COSMIC	COmmon System Main InterConnecting frame
COSMIC	COmputer Software Management and Information Center
COSMOS	COmputer System for Mainframe OperationS
COSTAR	Corrective Optics Space Telescope Axial Replacement [Space]
COT	Card Or Tape (NCR)
COTS    Commercial Off the Shelf                
CP	Campus Police (MIT, others probably too)
CP	Canadian Pacific
CP	Chemically Pure
CP	Command Post
CP	Command Processor
CP	the Canadian Press
CPA	Certified Public Accountant
CPE	Customer Premises Equipment
CPE	Customer Provided Equipment
CPFF	Cost Plus Fixed Fee
CPI	Characters Per Inch
CPI	Common Programming Interface
CPL	Combined Programming Language
CPM	Control Program for Microcomputers (sometimes CP/M)
CPM	Control Program Monitor (sometimes CP/M)
CPO	Chief Petty Officer
CPO	Chief Post Office
CPR	Canadian Pacific Railway
CPS	Characters Per Second
CPSR	Computer Professionals for Social Responsibility
CPU	Central Processing Unit
CPW	Certified Public Weigher
CQ	Change of Quarters
CR	Carriage Return (ASCII 15 octal)
CRA	Cambridge Redevelopment Authority
CRAF	Comet Rendezvous / Asteroid Flyby [Space]
CRAM	Card Random Access Memory (NCR, but maybe others)
CRC	Chemical Rubber Company
CRC	Cyclic Redundancy Check
CREG	Concentrated Range Extension with Gain
CREN	The Corporation for Research and Educational Networking (merge of BITNET and CSNet)
CRRES	Combined Release / Radiation Effects Satellite [Space]
CRRES	Combined Release and Radiation Effects Satellite [NASA]
CRT	Cathode Ray Tube (also generic reference to a terminal)
CRTC	Canadian Radio-television and Telecommunications Commission
C&S	Chivalry & Sorcery
CS	Civil Servant
CS	Computer Science; Computing Science
CS	County Seat
CSA	Confederate States of America
CSAB	Computing Sciences Accreditation Board
CSACS	Centralized Status, Alarm and Control System
CSC	Computer Sciences Corporation
CSDC	Circuit Switched Digital Capability
CSF	Critical Success Factor
CSI	Commercial Systems Integration
CSIS	Canadian Security and Intelligence Service
CSL	Coin Supervising Link 
CSM	Command and Service Module (Apollo spacecraft) [Space]
CSM	Command Sergeant Major
CSMA	Carrier Sense Multiple Access
CSMA/CA Carrier Sense Multiple Access with Collision Avoidance
CSMA/CD Carrier Sense Multiple Access with Collision Detection
CSNET	Computer + Science Network (merged with BITNET to make CREN)
CSO	Central Services Organization
CSOC	Consolidated Space Operations Center (at Colorado Springs)
CSP	Control Switching Point
CSR	Control and Status Register
CSR	Customer Service Representative [Telephony]
CSRG	Computer Systems Research Group
CSRS	civil Service Retirement System
CSS	Customer Switching System
CST	Central Standard Time
CSU	Channel Service Unit
CT	Central Time
C&T	Communications & Tracking [Space]
CT	Connecticut
CTC	Canadian Transport Commission
CTC	Centralized Traffic Control [Railroading]
CTD	Computing and Telecommunications Division
CTIO	Cerro Tololo Inter-american Observatory
CTIO	Cerro Tololo Interamerican Observatory [Space]
CTNE	Compania Telefonica Nacional de Espana
CTO     Chief Technology Officer       
CTS	Clear To Send (EIA RS-232-C)
CTS	Compatible Timesharing System
CTV	Canadian TeleVision network
CU	Close-Up
CUA	Common User Access
CUL	See You Later [Net jargon]
CV	Curriculum Vitae
CW	Car Wars
CW	Chemical Warfare
CW	Child Welfare
CW	Churchwarden
CW	Churdwarden
CW	Continuous Wave
CWO	Cash With Order
CWO	Chief Warrant Officer
CWRU	Case Western Reserve University
CXI	Common X-windows Interface
CY	Calendar Year
CYO	Catholic Youth Organization
CZ	Canal Zone
D	Depth
DA	Days after Acceptance
DA	Department of Agriculture
DA	Deposit Account
D/A	Digital to Analog converter
DA	Directory Assistance (/C = computerized, /M = Microfilm) [Telephony]
DA	District Attorney
DA	Don't Answer [Telephony] (may be more general)
DAC	Digital to Analog Converter
DA/C	Directory Assistance/Computerized
DACCS	Digital Access Cross Connect System [Telephony] (suspect, see DACS)
DACS	Digital Access Cross-connect System [Telephony]
DAD	Draft ADdendum
DAG	Directed Acyclic Graph
DAL	Dedicated Access Line [Telephony]
DA/M	Directory Assistance/Microfilm
DAP	Division Advisory Panel (of NSF (q.v.) DNCRI (q.v.))
DAR	Daughters of the American Revolution
DARE	Drug Abuse Resistance Education
DARPA	Defense Advanced Research Projects Agency (of the DoD, see also ARPA)
DASD	Direct Access Storage Device
DAT	Digital Audio Tape
DATA	Defense Air Transport Administration
DAV	Disabled American Veterans
DB	DataBase
db	decibel(s)
dba	doing business as
DBF	DBase Format
DBME	DataBase Managment Environment
dbms	DataBase Management System (rdbms for Relational ...)
DBRAD	Data Base Relational Application Directory
DC	Direct Current (dc, see also AC)
DC	District of Columbia
DCA	Defense Communications Agency
DCA	Distributed Communication Architecture
DCA	Document Content Architecture
DCC	Descriptive Cataloging Committee
DCCO	Defense Commercial Communications Office
DCD	Data Carrier Detect (sometimes CD (q.v.)) (EIA RS-232-C)
DCE	Data Communication Equipment
DCL	Digital Command Language
DCP	Distributed Communications Processor
DCTS	Dimension Custom Telephone Service
DD	Daredevils
DD	Data Dictionary
DD	Days after Date
DD	Demand Draft
DD	Dishonorable Discharge
DD	Disk Drive
DD	Doctor of Divinity
D&D	Dungeons & Dragons
DDC	Digital Data Converter
DDCU	DC-to-DC Converter Unit [Space]
DDD	Direct Distance Dialing [Telephony] (principally US, elsewhere STD)
DDL	Document Description Language
DDN	Defense Data Network
DDP	Distributed Data Processing
DDS	Dataphone Digital Service [AT&T]
DDS	Digital Data Service
DDS	Direct Digital Service
DDS	Doctor of Dental Science
DDS	Doctor of Dental Surgery
DDT	DEC Debugging Tape
DDT	Di- (pesticide)
DDT	Dynamic Debugging Technique
DE	Delaware
DEA	Drug Enforcement Agency [US Government]
DEAR	Department of Energy Acquisition Regulation
DEC	Digital Equipment Corporation [Corporate name]
DECUS	Digital Equipment Corporation Users Society
DES	Data Encryption Standard [NIST]
DEW	Distant Early Warning (as in DEW Line)
DF	Damage Free
D/F	Direction Finding
DFC	Distinguished Flying Cross
DFD	Data Flow Diagram
DFE	Data Flow Editor
DFM	Distinguished Flying Medal
DFN	Deutsche Forschungsnetz Verein (German Research Network Association)
DFRF	Dryden Flight Research Facility [Space]
DFS	Depth-First Search
DFW	Dallas-Ft.Worth (regional airport)
DG	Data General [Corporate name]
DG	Dei Gratia (by the grace of God)
DG	Director General
DGSC	Defense General Supply Center
DHHS	Department of Health and Human Services
DHSS	british Department of Health and Social Security
DHSS	Department of Health and Social Security (British)
DIA	Document Interchange Architecture
DIAD	(magnetic) Drum Information Assembler / Dispatcher
DIAL	Direct Information Access Line
DIAS	Defense Automatic Integrated System
DID	Direct Inward Dialing [Telephony]
DIF	Document Interchange Format
DIN	Deutsches Institut fur Normung
DIRE	Dire Is Really Emacs
DIRTFT  (Dirt Foot) Do it right the first time 
DIS	Draft International Standard [ISO]
DISA	Data Interchange Standards Association
DISOSS	Distributed Office Support System [IBM]
DIY	Do It Yourself
DJ	Disc Jockey
DLA	Defense Logistics Agency
DLI	Data Link Interface(?)
DLL	Data Link Layer [ISO OSI]
DLL	Dial Long Line equipment
DLO	Dead Letter Office
DM	Dungeon Master
DMA	Direct Memory Access
DMD	Doctor of Dental Medicine
DME	Distance Measuring Equipment
DMF	Probably part of an X.400 address in Europe
DMOS	Diffusion Metal Oxide Semiconductor (see MOS)
DMSP	Defense Meteorological Satellite Program [Space]
DMV	Department of Motor Vehicles
DMV	Department of Motor Vehicles (Calif)
DMZ	DeMilitarized Zone
DNA	DeoxyriboNucleic Acid
DNA	Digital Network Architecture [DEC]
DNCRI	[NSF] (q.v.) Division of Networking and Communications Research and Infrastructure
DNHR	Dynamic NonHierarchical Routing
DNIC	Data Network Identification Code [Telephony]
DNIS	Dialed Number Identification Service (see also DID) [Telephony]
DNL	Director of Naval Laboratories
DNR	Dialed Number Recorder [Telephony]
DNS	Domain Name System
DOA	Dead On Arrival
DOB	Date Of Birth
DOC	Dynamic Overload Control
DOD	Department Of Defense [US Government] (sometimes DoD)
DOE	Department of Energy [US Government]
DOHC	Dual OverHead Cams [Automotive]
DOMAIN	Distributed Operating Multi Access Interactive Network (Apollo)
DOS	Disk Operating System
DOT	Department Of Transportation [US Government]
DOT&E	Director, Operational Test and Evaluation
DOV	Data Over Voice [Telephony]
DOY	Day of Year
DP	Data Processing
DP	Dial Pulse [Telephony]
DP	Displaced Persons (expelled from native land)
DP	Display Postscript
DP	Double Penetration
DP	Double Play
DP	Draft Proposal
DPA	Delegation of Procurement Authority
DPANS	Draft Proposed American National Standard
DPI	Dots Per Inch
DPS	Display PostScript
DQ	Dairy Queen
DQ	Dragon Quest
DQDB	Distributed Queue Dual Bus (IEEE 802.6) [Telephony, Networking]
DQL	Database Query Language
DR	Dead Reckoning
DR	Dining Room
DRAM	Dynamic Random Access Memory (as opposed to static RAM)
DRD	Data Reading Device
DRE	Directional Reservation Equipment
DRG	Democratic Republic of Germany (East Germany)
DRI	Defense Research Internet
DRI	Digital Research, Incorporated [Corporate name]
d.s.	died single [Genealogy]
DS	Double-Sided
DS	Draft Standard
DSA	Dial System Assistance
DSE	Data Structure Editor
DSEE	Domain Software Engineering Environment
DSM	Distinguished Service Medal
DSO	Distinguished Service Order
DSP	Decessit Sine Prole (died without issue)
DSP	Digital Signal Processing
DSRI	Digital Standard Relational Interface
DSS	Decision Support System
DSS	Direct Station Selection [Telephony]
DST	Daylight Saving Time
DSTN	Double SuperTwisted Nematic
DSU	Digital Service Unit
DT	Delirium Tremens
DTE	Data Terminal Equipment
DTF	Dial Tone First payphone [Telephony]
DTMF	Dial Tone Multi Frequency [Telephony]
DTP	DeskTop Publishing
DTR	Data Terminal Ready (EIA RS-232-C)
DUI	Driving Under the Influence
DUT	Device Under Test
DV	Deo Vo lente (God willing)
DVM	Digital Volt Meter
DVM	Doctor of Veterinary Medicine
DWAPS	Defense Warehousing Automated Processing System
DWI	Died Without Issue [Genealogy]
DWI	Driving While Intoxicated
DWIM	Do What I Mean
DX	Distance (as in long distance radio communication)
DXT	Data eXtractT facility
d.y.	died young [Genealogy]
E	East
E	Espionage
EADASS	Engineering and Administrative Data AcquiSition System
EAFB	Edwards Air Force Base [Space]
EAN	Certainly part of an X.400 Address in Europe
EARN	European Academic Research Network
EAS	Extended Area Service (or Engineering Admin. System) 
EASI	European Academic Supercomputer Initiative (of IBM)
EBCDIC	Extended Binary Coded Decimal Interchange Code
EC	Exchange Carrier [Telephony]
ECAFE	Economic Commission for Africa and the Far East
ECASS	Electronically Controlled Automatic Switching System
ECASS	Export Control Automated Support System
ECC	Error Correction Code
ECC	Error Correction Code (corrects error in memory or transmission)
ECCM	Electronic Counter-CounterMeasures
ECDO	Electronic Community Dial Office
ECG	ElectroCardioGram
ECL	Emitter Coupled Logic (see also TTL)
ECLSS	Environmental Control and Life Support System [Space]
ECM	Electronic Counter Measure
ECM	European Common Market
ECMA	European Computer Manufacturers Association
ECO	Ecological
ECO	Electronic Central Office
ECO	Engineering Change Order
ECPA	Electronic Communications Privacy Act [US law]
ECS	Environmental Control System [Space]
ECT	ElectroConvulsive Therapy
ECV	Electric Cargo Vehicle [NASA OEXP]
ED&D	Expert Dungeons & Dragons
EDGAR	Electronic Data Gathering, Analysis, and Retrieval
EDI	Electronic Data Interchange
EDIF	Electronic Design Interchange Format
EDO	Extended Duration Orbiter [Space]
EDP	Electronic Data Processing
EDS	Electronic Data Systems
EDT	Eastern Daylight Time
EDTA	Ethylene Diamine Tetraacetic Acid
EDTCC	Electronic Data Transmission Communications Central
EE	Electrical Engineer
EE	Electrical or Electronics Engineer
EEC	European Economic Community
EEC	European Economic Comunity
EEG	ElectroEncephaloGram
EEL	Epsilon Extension Language
E&EO	Errors and Omissions Excepted
EEPROM	Electrically Erasable Programmable Read Only Memory
EFF	Electronic Frontier Foundation
e.g.	??? (Latin(?): for example)
EGA	Enhanced Graphics Adapter
EGP	Exterior Gateway Protocol [Internet]
EGRET	Energetic Gamma Ray Experiment Telescope (on GRO) [Space]
EHF	Extremely High Frequency (30-300GHz)
EIA	Electronic Industries Association
EINE	EINE Is Not Emacs
EISA	Extended Industry-Standard Architecture
EISS	European Intelligence Support System
EKG	ElectroKardioGramm (see ECG)
EL	ElectroLuminescent (as in display)
ELF	Extremely Low Frequency
ELO	Electric Light Orchestra
ELP	Emerson, Lake and Palmer (or Powell)
ELV	Expendable Launch Vehicle [Space]
E&M	``Ear and Mouth''; receive and transmit leads of a signalling system
EM	Enlisted Man (see EW)
EMA	Electronic Mail Association
EMACS	Eight Megabytes And Constantly Swapping
E-MAIL	Electronic MAIL
EMF	ElectroMotive Force
EMF	ElectroMotive Force (voltage)
EMI	ElectroMagnetic Interference
EMP	Electromagnetic Pulse
EMPRESS EnvironMental Pulse Radiation Environment Simulator for Ships
EMR	ElectroMagetic Response
EMR	ElectroMagnetic Response
EMS	Electronic Message System
EMS	Extended Memory Specification
EMT	Emergency Medical Technician
EMU	ElectroMagnetic Unit
EMU	Extravehicular Mobility Unit [Space]
ENIAC	Electronic Numerical Integrator and Calculator
EO	End Office [Telephony]
EO	Erasable Optical
EOF	End Of File
EOM	End Of Month
EOS	Earth Observing System [Space]
EOWG	Engineering and Operations Working Group (under FNC)
EP	Experience Points
EP	Extended Play
EPA	Environmental Protection Agency
EPOS	Engineering and Project-management Oriented Support system
EPRI	Electric Power Research Institute
EPROM	Erasable Programmable Read Only Memory
EPS	Encapsulated PostScript
EPT	Empire of the Petal Throne
EQ	Educational Quotient (see IQ)
ER	Emergency Room
ERA	Earned Run Average
ERA	Entity-Relationship-Attribute
ERA	Equal Rights Amendment
ERD	Entity-Relation Diagram
ERE	Entity Relationship Editor
ERT	Earth Resources Technology [Space]
ES	Expert System
ESA	European Space Agency
ESA	European Space Agency [Space]
ESAC	Electronic Systems Assistance Center
ESDI	Enhanced Standard Device Interface
ESE	East South East
ESF	Extended Superframe Format [Telephony]
ESM	Electronic Support Measures
ESnet	Energy Sciences network (DoE) [Networking]
ESO	European Southern Observatory
ESO	European Southern Observatory [Space]
ESP	Extra Sensory Perception
ESPS	Entropic Signal Processing System
ESS	Electronic Switching System [Telephony]
ESSEX	Experimental Solid State EXchange
EST	Eastern Standard Time
ET	Eastern Time
ET	Extra Terrestrial [Space]
ET	(Shuttle) External Tank [Space]
ETA	Estimated Time of Arrival
ET/ACC	External Tank/Aft Cargo Carrier (see also ET) [Space]
ETC	Et cetera, and so on...
ETD	Estimated Time of Departure
ETFD	Electronic Toll Fraud Device [Telephony]
ETH	Eidgn\:oessiche Technische Hochschule (Swiss Federal Institute of Technology)
ETLA	Extended Three Letter Acronym [Space]
ETO	Earth-to-Orbit [Space]
ETR	Eastern Test Range [Space]
ETS	Electronic Translator System
ETV	Education TeleVision
EUUG	European Unix User Group
EUV	Extreme UltraViolet
EUV	Extreme UltraViolet [Space]
EUVE	Extreme UltraViolet Explorer [Space]
EVA	ExtraVehicular Activity
EVA	ExtraVehicular Activity [Space]
EVX	Electronic Voice eXchange
EW	Electronic Warfare
EW	Enlisted Woman (see EM)
EWOS	European Workshop for Open Systems
FA	Football Association (British soccer--a word derived from Association)
FAA	Federal Aviation Agency [US Government]
FACD	Foreign Area Customer Dialing
FAO	Food and Agriculture Organization [US Government]
FAQ	Frequently Asked Questions [Space]
FAR	Federal Acquisition Regulations
FAS	Foreign Agricultural Service
FAS	Free Alongside Ship
FASST	Flexible Architecture Standard System Technology
FAST	Fast Auroral SnapshoT explorer [Space]
FAT	Foreign Area Translation
FAX	FAcsimile
FB	Freight Bill
FBI	Federal Bureau of Investigation [US Government]
FCC	Federal Communications Commission [US Government]
FCC	Federal Computer Conference
FCCSET	Federal Coordinating Committee for Science, Education and Technology (under OSTP) {Maybe Eng. for Edu.??}
FCO	Field Change Order
FCO	Frequency Controlled Oscillator
FCS	Frame Check Sequence
FDA	Food and Drug Administration [US Government]
FDDI	Fiber Digital Data Interface
FDDI	Fiber Distributed Data Interface
FDHD	Floppy Drive High Density
FDIC	Federal Deposit Insurance Corporation
FDIC	Federal Deposit Insurance Corporation [US Government]
FDM	Frequency Division Multiplexing
FDR	Franklin Delano Roosevelt [US President]
FE	Field Engineer (see also CE, SE)
FEA	Finite Element Analysis
FEDSIM	FEDeral Systems Integration and Management center
FEMA	Federal Emergency Management Agency
FEMF	Foreign EMF (q.v.) (a.k.a. Cross Battery) [Telephony]
FEPC	Fair Employment Practices Commission
FEPG	Federal Engineering Planning Group (of FNC under EOWG, originally of FRICC)
FERS	Federal Employees Retirement System
FET	Federal Excise Tax
FET	Field Effect Transistor
FFA	Future Farmers of America
FFT	Fast Fourier Transform
FFT	Fast Fourier Transform [Space]
FG-A	Feature Group A [Telephony] (Line Side termination for LD carriers)
FG-B	Feature Group B [Telephony] (Trunk Side termination for LD carriers (aka ENFIA B), 950 service)
FG-D	Feature Group D [Telephony] (Trunk Side termination for LD carriers, 1+ service)
FGS	Fine Guidance Sensors (on HST) [Space]
FHA	Federal Home Administration
FHA	Future Homemakers of America
FIB	Focused Ion Beam
FICA	Federal Insurance Contributions Act
FIDO	Fog Investigation Dispersal Operation
FIFO	First In First Out (as in registers and buffers)
FILO	First In Last Out (see also FIFO)
FIMS	Forms Interface Management System
FINE	FINE Is Not Emacs
FIO	Frequency In and Out
FIPS	Federal Information Processing Standard
FIR	Far InfraRed [Space]
FIR	Finite Impulse Response
FIRMR	Federal Information Resource Management Regulation
FIT	Federal Information Technologies, inc.
FITS	Flexible Image Transport System [Space]
FIX	Federal Inter-agency eXchange [Networking]
FL	Florida
FLACC	Full Level Algol Checkout Compiler
FLEA	Four Letter Extended Acronym
FLL	Fixed Loss Loop [Telephony]
FLOP	FLoating point OPeration
FLOPS	FLoating-point OPerations per Second
FLRA	Federal Labor Relations Authority
FM	Frequency Modulation
FMB	Federal Maritime Board
FMCS	Federal Mediation and Conciliation Service
FMR	Follow Me Roaming [Telephony]
FMS	Financial Management Service (Treasury Dept) [US Government]
FMS	Forms Management System
FNC	Federal Networking Council (formerly FRICC) [US Government] (under OSTP)
FO	Foreign Office
FO	Forward Observer
FOAC	Federal Office Automation Center
FOB	Free On Board
FOB	Full Of Bull (aperiodical of) [TMRC]
FOC	Faint Object Camera (on HST) [Space]
FOC	Free Of Charge
FOIA	Freedom Of Information Act
FOIMS	Field Office Information Management System
FOIRL	Fiber Optic Inter(?) Repeater(?) Link(?) [Ethernet]
FOOBAR	See FUBAR [Net jargon]
FOR	Free On Rail
FORCS	Faa's Operational Reporting Communication System
FORD	Fix Or Repair Daily [Humor]
FORD	Found On Road Dead [Humor]
FOS	Faint Object Spectrograph (on HST) [Space]
FOSE	Federal Office Systems Exposition
FOT	Fiber Optic Transceiver [Ethernet]
FOT	Free On Truck
FOV	Field Of View
FPA	Floating Point Accelerator
FPC	Fish Protein Concentrate
FPE	Floating Point Engine
FPHA	Federal Public Housing Authority
FPLA	Field Programmable Logic Array (see PLA)
FPM	Feet Per Minute
FPO	Field Post Office
FPO	Fleet Post Office
fps	Feet Per Second
FPU	Floating Point Unit
FQDN	Fully Qualified Domain Name [TCP/IP] (DNS)
FR	Frame Relay [Telephony, Networking]
FRACTAL FRACTional dimensionAL
FRED	Fred Resembles Emacs Deliberately
FRG	Federal Republic of Germany (West Germany)
FRICC	Federal Research Internet Coordinating Committee (now FNC, q.v.) [Networking, US Government]
FROG	Free Rocket Over Ground
FRPG	Fantasy Role Playing Game
FRS	Federal Reserve System
FS	Field Service
FS	File System
FS	Full Standard
FSF	Free Software Foundation
FSK	Frequency Shift Keying
FSLIC	Federal Savings and Loan Insurance Corporation
FSS	Federal Supply Service
FSW	Forward Swept Wings
Ft	Foot
FTAM	File Transfer And Management (ISO upscale FTP)
FTC	Federal Trade Commission
FTL	Faster Than Light
FTP	File Transfer Protocol (esp. of the TCP/IP suite)
FTS	Federal Telecommunications System [Telephony, US Government]
FTS	Flight Telerobotic Servicer [Space]
FUBAR	F***ed Up Beyond All Recognition/Repair
FUBAR	Fouled Up Beyond All Recognition/Repair
FUSE	Far Ultraviolet Spectroscopic Explorer [Space]
FW	Fringeworthy
FWD	Front Wheel Drive
FWHM	Full Width at Half Maximum [Space]
FX	Foriegn eXchange [Telephony]
FY	Fiscal Year
FYI	For Your Information
G	General audiences [Movie rating]
G	Gravity
GA	Gamblers Anonymous
GA	General Assembly
GA	General Average
GA	General of the Army
GA	Georgia
GAAP	Generally Accepted Accounting Principles
GAB	Group Audio Bridging [Telephony]
Gaia	Earth's self-sustaining Biosphere (Not an acronym, from some ancient language, I think)
GAN	Global Area Network
GAO	General Accounting Office [US Government]
GAR	Grand Army of the Republic
GARR	Gruppo Arminizzazione Rete por la Ricerca (Italian Research Network Harmonization Group)
GAS	Get-Away Special [Space]
GATT	General Agreement on Tariffs and Trade
GAW	Guaranteed Annual Wage
GAW	Guarenteed Annual Wage
GB	Gangbusters
GB	GigaByte
GB	Great Britain
GBIP	General Purpose Interface Bus
GBT	Green Bank Telescope [Space]
GC	Garbage Collection (LISP)
GC	Gas Chromatograph (or Chromatography)
GCA	Ground Controlled Approach
GCC	Gnu C Compiler
GCD	Ground Controlled Descent
GCL	Graphics Command Language
GCM	General Court Martial
GCR	Group-Coded Recording (magnetic tape, 6250 bpi)
GCT	Greenwich Civil Time
GCVS	General Catalog of Variable Stars [Space]
GDB	Gnu DeBugger
GDP	Gross Domestic Product
GDS	Great Dark Spot [Space]
GE	General Electric
GEM	Giotto Extended Mission [Space]
GEM	Graphics Environment Manager
GEO	Geosynchronous Earth Orbit [Space]
GHQ	General HeadQuarters
GHRS	Goddard High Resolution Spectrograph (on HST) [Space]
GHz	Giga HertZ (unit of frequency, 1,000,000,000 cycles per second)
GI	Galvanized Iron
GI	Gastro Intestinal (as in upper GI)
GI	General Issue
GI	Government Issue
GIF	Graphics Interchange Format
GIGO	Garbage In Garbage Out
GIN	Graphics INput
GISS	Goddard Institute for Space Studies
GKS	Graphical Kernel Standard
GKS	Graphics Kernel System
GM	Game Master
GM	General Manager
GM	General Motors [Corporate name, Automobile]
GM	Guided Missile
GMBH	Gesellschaft Mit Beschraenkter Haftung
GMC	Giant Molecular Cloud [Space]
GMD	Gesellschaft f\:ur Mathematik und Datenverarbeitung (German Institute for Mathematics and Data Processing)
GMRT	Giant Meter-wave Radio Telescope [Space]
GMT	Greenwich Mean Time (also called UT)
GNP	Gross National Product
GNU	GNU's Not Unix
GOES	Geostationary Orbiting Environmental Satellite [Space]
GOES	Geostationary Orbiting Environmental Satellites [Space]
GOSIP	Government Open Systems Interconnection Profile (calls for government procurement of ISO/CCITT products)
GOSIP	Government OSI Profile
GP	General Practitioner
GP	General Purpose (RR engines and origin of Jeep) [Railroading, Automobile]
GPC	General Purpose Computer [Space]
GPI	Graphics Programming Interface
GPIB	General Purpose Interface Bus
GPIB	General-Purpose Interface Bus
GPL	GNU General Public Licence
GPO	General Post Office
GPO	Government Printing Office
GPS	Global Positioning System
GPS	Global Positioning System [Space]
GQ	General Quarters
GRB	Gamma Ray Burst(er)
GREP	Global Regular Expression Print, g/re/p, (UNIX command)
GREP	Global Regular Expression Print [UNIX]
GRO	Gamma Ray Observatory [Space]
GRS	Gamma Ray Spectrometer (on Mars Observer) [Space]
GRS	Great Red Spot [Space]
GS	General Schedule
GS	Glide Slope
GSA	General Services Administration
GSA	General Services Adminstration [US Government]
GSA	Girl Scouts of America
GSBCA	General Services administration Board of Contract Appeals
GSC	Guide Star Catalog (for HST) [Space]
GSFC	Goddard Space Flight Center (Greenbelt, MD) [NASA, Space]
GSI	Gesellschaft f\:ur Schwerionenforschung (German Federal Research Institute for Heavy Ion Research)
GSM	Global System Mobile
GSM	Groupe Speciale Mobile (Committee Designing preceding)
GSTS	Ground-based Surveillance and Tracking System
GT	Gross Ton
GTE	General Telephone and Electric [Corporate name]
GTO	Geostationary Transfer Orbit [Space]
GTSI	Government Technology Services, inc.
GUI	Graphical User Interface
GW	Gamma World
GWEN	Ground Wave Emergency Network
GWM	Generic Window Manager [X]
H	Harn
H	Height
HACD	Home Area Customer Dialing
HAL	Heuristically programmed ALgorithmic computer (movie 2001)
HAM	Hold And Modify
HAO	High Altitude Observatory [Space]
Hb	HemogloBin
HBM	Her British Majesty; His British Majesty
HBO	Home Box Office
HC	Holy Communion
HC	House of Commons
HCFA	Health Care Financing Administration
HCFC	hydrochlorofluorocarbon [Chemical]
HCL	High Cost of Living
HD	Hard Disk
HD	Heavy Duty
HD	Henry Draper catalog entry [Space]
HDA	Head Disk Assembly (in winchester disk drives)
HDBV	Host Data Base View
HDL	High Density Lipoprotein
HDLC	High-level Data Link Control [Networking]
HDTV	High Definition Television
HE	His Eminence
HE	His Excellency
HEAO	High Energy Astronomical Observatory [Space]
HEDM	High Energy-Density Matter [Space]
HEMP	Help End Marijuana Prohibition
HEO	High Earth Orbit [Space]
HEPnet	High Energy Physics network [Networking]
HERO	Hazards of Electromagnetic Radiation to Ordnance
HF	High Fantasy
HF	High Frequency (3-30MHz)
HFE	Human Factors Engineering
HFS	Hierarchical File System
HGA	High Gain Antenna [Space]
HHS	(US Department of) Health and Human Services
HI	Hawaii
HIIPS	Hud Integrated Information Processing Services
HLC	Heavy Lift Capability [Space]
HLL	High-Level Language
HLV	Heavy Lift Vehicle [Space]
HMC	Halley Multicolor Camera (on Giotto) [Space]
HMOS	High performance Metal Oxide Semiconductor (see MOS)
HMS	His/Her Majesty's Ship
HMT	His/Her Majesty's Transport
HNPA	Home Numbering Plan Area [Telephony]
HOBIS	HOtel Billing Information System 
HOL	High-Order System
HOTOL	HOrizontal Take-Off and Landing
HP	Hewlett Packard, Inc. [Corporate name]
HP	High Pressure
HP	Higher Power (sort of an AA "in" term, usually God)
HP	Hit Points
HP	HorsePower
HPGe	High Purity Germanium
HPL/T	High-Productivity Languages/Tools
HQ	HeadQuarters
HR	Hertzsprung-Russell (diagram) [Space]
HR	House of Representatives
HRH	Her Royal Highness
HRH	His Royal Highness
HRI	High Resolution Imager (on ROSAT) [Space]
HS	High School
HSB	Hue, Saturation, Brightness
HSP	High Speed Photometer (on HST) [Space]
HST	Hawaiian Standard Time
HST	Hubble Space Telescope [Space]
HT	High Tension (as in electric power transmission)
HTK	Hits To Kill
HTML    Hyper Text Markup Language
HTTP    Hyper Text Transfer Protocol   
HUAC	House Unamerican Activities Committee
HUD	Heads Up Display
HUD	Housing and Urban Development [US Government]
HUPD	Harvard University Police Department
HUT	Hopkins Ultraviolet Telescope (ASTRO package) [Space]
HV	High Voltage
HVAC	Heating, Ventilation, and Air Conditioning
HW2000	Highway 2000
HWM	High-Water Mark
Hz	HertZ (unit of frequency, cycles per second)
IAB	Internet Activities Board [Networking]
IAEA	International Atomic Energy Agency
IANA	Internet Assigned Numbers Authority ([email protected])
IATA	International Air Transport Association
IAU	International Astronomical Union [Space]
IAUC	IAU Circular [Space]
IBM	Ingrained Batch Mentality
IBM	International Business Machines, Inc. [Corporate name]
IBM	Itty Bitty Machines
IBT	Illinois Bell Telephone
IC	Integrated Circuit
IC	Interexchange Carrier [Telephony] (see also IEC, IXC)
ICB	Interstate Computer Bank
ICBM	InterContinental Ballistic Missile
ICE	In-Circuit Emulator
ICE	International Cometary Explorer [Space]
ICI	Imperial Chemical Industries
ICJ	International Court of Justice
ICL	International Computers Ltd.
ICMP	Internet Control Message Protocol
ICP	Integrated Channel Processor
ICP	Inventory Control Points
ICRC	International Cosmic Ray Conference
ID	Idaho
ID	IDentification
IDA	Intercommunication Data Areas
IDA	International Dark-sky Association [Space]
IDA	International Development Association
IDDD	International Direct Distance Dial [Telephony]
IDE	Interactive Development Environments, inc
IDF	Intermediate Distributing Frame [Telephony]
IDL	Interactive Data Language [Space]
IDV	Interlibrational Derived Vehicle [Space]
i.e.	???? (Latin(?): in other words (?))
IE	Indo-European
IEC	Inter-Exchange Carrier [Telephony] (see also IC, IXC)
IEE	Institute of Electrical Engineers [UK]
IEEE	Institute of Electrical and Electronic Engineers
IETF	Internet Engineering Task Force
IF	Intermediate Frequency (as in IF stage)
IFB	Invitation For Bids
IFC	International Finance Corporation
IFC	International Freighting Corporation
IFF	Identification - Friend or Foe
IFF	Interchange File Format
IFLA	International Federation of Library Associations
IFR	Instrument Flight Rules [Aviation]
IGES	Initial Graphics Exchange Standard
IGM	InterGalactic Medium [Space]
IGY	International Geophysical Year
IGY	International Geophysical Year [Space]
IHP	Indicated HorsePower
IHS	Integrated Hospital Support
IIA	Information Industry Association
IIE	Institute of Industrial Engineers
IIHF	International Ice Hockey Federation
IIL	Integrated Injection Logic
ILO	International Labor Organization
ILS	Instrument Landing System
ILV	Industrial Launch Vehicle [Space]
IMF	International Monetary Fund
IMHO	In My Humble Opinion [Net jargon]
IMO	In My Opinion [Net jargon]
IMP	Interface Message Processor [ARPANET/MILNET] (replaced by PSN)
IMSL	International Mathematical Subroutine Library
IN	Indiana
INADS	INitialization and ADministration System [Telephony]
INRA	Iesus Nazerenus Rex Iudaeorum (Jesus of Nazareth, King of the Jews)
INRIA	Institut National de Recherche en Informatique et Automatique
INS	Immigration and Naturalization Service
In-situ In Place [Latin]
INSTITUTE	INSTITUTE's Name Shows That It's Totally Unrelated To EMACS
INTAP	INteroperability Technology Association for information Processing
INWATS	INward Wide Area Telephone Service [Telephony]
I/O	Input/Output
IO	Input/Output (sometimes I/O)
IOC	International Operating Center [Telephony, US]
IOD	Identified Outward Dialing
IOOF	International Order of Odd Fellows
IOTA	Infrared-Optical Telescope Array [Space]
IOTA	International Occultation Timing Association [Space]
IOU	I Owe you(U)
IP	Information Provider [Telephony]
IP	Innings Pitched
IP	Intermediate Point
IP	Internet Protocol
IPC	Inter-Process Communication
IPE	Integrated Programming Environment
IPMS	InterPersonal Message Services
IPS	Inertial Pointing System [Space]
IPS	Information Processing Standards
IPSE	Integrated Project-Support Environment
IQ	Intelligence Quotient (see EQ)
IR	Index Register
IR	Infra-Red
IRA	Individual Retirement Account
IRA	Irish Republican Army
IRAF	Image Reduction and Analysis Facility [Space]
IRAS	InfraRed Astronomical Satellite [Space]
IRBM	Intermediate Range Ballistic Missile
IRDS	Information Resource Dictionary Standard
IRDS	InfraRed Detection Set
IRE	Institute of Radio Engineers (old name for the now IEEE, which see)
IRM	Information Resources Management
IRMS	Information Resources Management Service
IRS	Internal Revenue Service
IRTF	Internet Research Task Force
IS	Information Systems
IS	International Standard [ISO] (Beyond the DIS Stage)
ISA	Industry-Standard Architecture
ISAM	Indexed Sequential Access Method
ISAS	Institute of Space and Astronautical Science (Japan) [Space]
ISBD	International Bibliographic Description
ISC	Information Services Center
ISC	International Switching Center
ISCH	Interstitial-Cell-Stimulating Hormone (same as LH)
ISDN	Integrated Services Digital Network [Telephony]
ISDT	Integrated Systems Development Tool
ISEE	International Sun Earth Explorer (usually ISEE-3)
ISF	Information Systems Factory
ISFUG	Integrated Software Federal User Group
ISI	Information Sciences Institute
ISM	InterStellar Medium [Space]
ISO	Infrared Space Observatory [Space]
ISO	International Organization for Standardization 
ISO	International Standards Organization [Space]
ISODE	ISO Development Environment
ISOO	Information Security Oversight Office
ISPM	International Solar Polar Mission
ISPM	International Solar Polar Mission (now Ulysses) [Space]
ISR	Institute of Snow Research
ISRG	Independent Space Research Group
ISV	Independent Software Vendor
ISY	International Space Year [Space]
IT	Industrial Technology
IT	Information Technology
ITC	Inter-Task Communication
ITS	Incompatible Timesharing System
ITT	International Telephone and Telegraph
ITU	International Telecommunications Union
ITUSA	IT Users Standards Association
IUE	International Ultraviolet Explorer [Space]
IUS	Inertial Upper Stage
IUS	Inertial Upper Stage [Space]
IUV	Interlibrational Utility Vehicle [Space]
IXC	Inter-eXchange Carrier [Telephony] (see also IC, IEC)
IXI	International (pan-European) X.25 Infrastructure
JACM	Journal of the Association for Computing Machinery
JANET	Joint Academic Network (UK)
JBS	John Birch Society
JC	Jesus Christ
JC	Joint Compound (plumbing)
JC	Julius Caesar
JC	Junior College
JCA	Jewelry Crafts Association
JCAC	Joint Civil Affairs Committee
JCAE	Joint Committee on Atomic Energy
JCEE	Joint Council on Economic Education
JCET	Joint Council on Educational Television
JCS	Joint Chiefs of Staff
JD	Justice Department
JDS	John Dewey Society
JEM	Japanese Experiment Module (for SSF) [Space]
JES	John Ericsson Society
JET	Joint European Torus (fusion research)
JFK	John F. Kennedy
JFK	John F. Kennedy (international airport)
JFMIP	Joint Financial Management Improvement Program
JGR	Journal of Geophysical Research
JGR	Journal of Geophysical Research [Space]
JI	Justice, Inc.
JIC	Joint Intelligence Center
JIC	Just in Case
JILA	Joint Institute for Laboratory Astrophysics [Space]
JIM	Job Information Memorandum
JINTACCS	Joint INteroperability of TActical Command and Control Systems
JIS	Japan Industrial Standards
JISC	Japanese Industrial Standards Committee
JIT	Just In Time
JMS	John Milton Society
JNT	Joint Network Team (UK)
JO	Job Order
JO	Junior Officer
JOVE	Jonathan's Own Version of Emacs
JOVIAL	Jules Own Version of the International Algorithmic Language
JPL	Jet Propulsion Laboratory
JPL	Jet Propulsion Laboratory [Space]
JRC	Junior Red Cross
JSC	Johnson Space Center
JSC	Johnson Space Center (NASA) [Space]
JSD	Jackson System Development
JSRC	Joint Services Review Committee
JTIDS	Joint Tactical Information Distribution Systems
JV	Junior Varsity
JvNC	John von Neumann (Super Computer) Center
JvNCnet John von Neumann (Super Computer) Center network
K	Kilo- (metric 1000)
K9	canine (K9 corps - army dogs)
KAIST	Korean Advanced Institute of Science and Technology
KAO	Kuiper Airborne Observatory [Space]
KB	KiloByte
KC	King's Counsel (QC when queen reigning)
KC	Knights of Columbus
KD	Kiln Dried
KD	Knocked Down
KDCI	Key Display Call Indicator
KERMIT	Kl-10 Error-free Reciprocal Micro Interconnect over Tty lines
KET	Kentucky Educational Television
KHz	Kilo HertZ (unit of frequency, 1000 cycles per second)
KI	Kiwanis International
KIA	Killed In Action
KIAS	Knot Indicated Air Speed
Km	Kilometers
KO	Knock Out [Boxing, Electric]
KP	Key Pulse [Telephony]
KP	Kitchen Police
KPNO	Kitt Peak National Observatory
KPO	KeyPunch Operator
KQC	King's College London
K&R	Kernighan and Ritchie, the c programming language
KS	King's Scholar
KSC	Kennedy Space Center (NASA) [Space]
KSU	Key System Unit [Telephony]
KTB	Cretaceous-Tertiary Boundary (from German) [Space]
KTS	Key Telephone System [Telephony]
KTU	Key Telephone Unit [Telephony]
KWIC	Key Word In Context
KY	Kentucky
L1	Lagrange Point #1 35,000 Miles above moon [Space]
L2	Lagrange Point #2 40,000 Miles behind moon [Space]
L3	Lagrange Point #3 (?? 35,000 Miles below moon) [Space]
L4	Lagrange Point #4 240,000 mile Earth orbit [Space]
L5	Lagrange Point #5 240,000 mile Earth orbit [Space]
LA	Los Angeles
LA	Louisiana
LA	Low Altitude
LADAR	LAser Detection And Ranging
LAM	Master of Liberal Arts
LAMA	Local Automatic Message Accounting [Telephony]
LAN	Local Apparent Noon
LAN	Local Area Network
LANL	Los Alamos National Laboratory [Space]
LANL	Los Alamos (NM) National Laboratory
LAPB	Link Access Procedure (Balanced)
LAPD	Link Access Procedure (??)
LAPD	Los Angeles (CA, US) Police Department
LAR	Local Acquisition Radar
LaRC	Langley Research Center (NASA) [Space]
LASER	Light Amplification by Stimulated Emission of Radiation
LAT	Local Apparent Time
LATA	Local Access and Transport Area [Telephony]
LAX	Los Angeles International Airport
LB	Light Bomber
LB	pound (LiBra)
LBHS	Long Beach High School
LBL	Lawrence Berkeley (Calif.) Labs
LBS	Pounds
LC	inductor-Capacitor circuit (as in filters, L is symbol inductance)
LCD	Liquid Crystal Display
LCD	Lowest Common Denominator
LCDR	Lieutenant Commander
LCL	Less than Carload Lot [Railroading]
LCL	Lunar Cargo Lander [NASA OEXP]
LCM	Least Common Multiple
LCM	Life Cycle Management
LCS	Laboratory for Computer Science (of MIT)
LCT	Landing Craft Tanks
LD	Long Distance [Telephony]
LDC	Long Distance Carrier [Telephony]
LDEF	Long Duration Exposure Facility [Space, NASA]
LDF	Large Deployable Reflector [Space]
LDL	Low Density Lipoprotein
LDX	Long Distance eXtender [Telephony]
LEAP	Low-power Enhanced At Portable
LEC	Local Exchange Carrier [Telephony]
LED	Light Emitting Diode
LEM	Lunar Excursion Module (a.k.a. LM) (Apollo spacecraft) [Space]
LEO	Low Earth Orbit [Space]
LEP	Large Electron-Positron collider [CERN]
LeRC	Lewis Research Center (NASA) [Space]
LEST	Large Earth-based Solar Telescope [Space]
LF	Low Frequency (30-300KHz)
LFSA	List of Frequently Seen Acronyms (!) [Space]
LGA	Low Gain Antenna [Space]
LGM	Little Green Men [Space]
LH	Left Hand
LH	Liquid Hydrogen (also LH2 or LHX) [Space]
LH	Lower Half
LH	Luteinizing Hormone (same as ISCH)
LHC	Large Hadron Collider [CERN]
LHD	Litterarum Humaniorum Doctor (doctor of human letters)
LHS	Left Hand Side
LI	Long Island
LIFIA	Laboratoire d'Informatique Fondamentale et d'Intelligence Artificielle
LIFO	Last In First Out (see FIFO)
LINC	Laboratory INstrument Computer
LISA	Large Installation Systems Administration (USENIX specific?)
LISP	LISt Processing Language
LIU	Line Interface Unit
LL	Late Latin
LL	Long Lines [Telephony]
LLB	Legum Baccalaureus (bachelor of laws)
LLD	Legum doctor (doctor of laws)
LLN	Line Link Network [Telephony]
LLNL	Lawrence Livermore National Laboratories
LLO	Low Lunar Orbit [Space]
LLOX	Lunar Liquid Oxygen [Space]
LLP	Line Link Pulsing [Telephony]
LM	Life Master (Contract Bridge ranking)
LM	Lunar Module (a.k.a. LEM) (Apollo spacecraft) [Space]
LMC	Large Magellanic Cloud (see SMC)
LMC	Large Magellanic Cloud [Space]
LMOS	Line Maintenance Operations System [Telephony, AT&T]
LN2	Liquid N2 (Nitrogen) [Space]
LNG	Liquified Natural Gas
LOA	Lands of Adventure
LOFT	Launch Operations Flight Test [Space]
LOL     Laughing Out Loud
LOOPS	Lisp Object Oriented Programming System
LOP	Lines Of Position
LOSF	Lunar Orbit Staging Facility [Space]
LOTS	Low Overhead Timesharing System
LOX	Liquid Oxygen
LOX	Liquid OXygen [Space]
LP	Long Play(ing) (record)
LP	Low Pressure
LPC	Linear Predictive Coding (speech processing)
LPDA	Link Problem Determination Aid
LPF	League for Programming Freedom
LPG	Liquefied Petroleum Gas
LPG	Low Pressure Gas
LPL	Lunar Personnel Lander [NASA OEXP]
LPN	Licensed Practical Nurse
LPP	Licensed Program Products
LPR	Line PrinteR
LPT	Lunar Propellant Tanker [NASA OEXP]
LPV	Lunar Piloted Vehicle [NASA OEXP]
LRB	Liquid Rocket Booster [Space]
LRBM	Long Range Ballistic Missile
LRC	Longitudinal Redundancy Character
LRU	Least Recently Used
LRU	Line Replaceable Unit
LRV	Light Rail Vehicle [Railroading]
LS	Left Side
LS	Letter Signed
LS	Locus Sigilli (place of seal)
LSAP	Logical(?, maybe Link) Service Access Point [OSI, Networking]
LSB	Least Significant Bit; Least Significant Byte
LSB	Lower Side Band
LSC	Lecture Series Committee (of MIT)
LSC	LightSpeed C
LSD	Least Significant Digit
LSD	LySergic acid Diethylamide
LSD	pounds (Libra), shillings (Sestertii), and (old) pence (Denarii)
LSI	Large Scale Integration
LSP	LightSpeed Pascal
LSR	Local Standard of Rest [Space]
LSS	Life Support System
LSS	Loop Switching System
LSSD	Level-Sensitive Scan Detection
LT	Long Ton
LT	Low Tension
LTC	Lieutenant Colonel
LTJG	Lieutenant Junior Grade
LTL	Less than Truckload Lot
LTP	Lunar Transient Phenomenon [Space]
LUG	Local Users Group
LUT	Look-Up Table
LWM	Low-Water Mark
LWT	London Weekend Television [Corporate name]
LZ	Landing Zone
M	Mega- (metric 10^6)
m	meter(s)
m	milli- (metric 1/1000)
M	Miniatures
MA	Massachusetts [US state postal designation]
MAAP	Maintenance And Administration Panel
MAC	an MIT interdepartmental lab (stands for many things) (renamed to LCS)
MAC	Media Access Control
MAC	Medium Access Control
MAC	Military Air Command
MACSYMA project MAC's SYmbolic MAnipulation System
MAD	Mutual Assured Destruction
MADD	Mothers Against Drunk Driving
MAG	Magazine
MAN	Metropolitan Area Network
MAP	Manufacturing Automation Protocol
MAP/TOP Manufacturing Automation Protocol/Technical Office Protocol
MARBI	MAchine Readable form of Bibliographic Information
MARC	MAchine Readable card Catalog
MARS	Multiuser Archival and Retrieval System
MASC	Multiple Award Schedule Contract
MASER	Microwave Amplification by Stimulated Emission of Radiation
MASH	Mobile Army Surgical Hospital
MAST	Multi-Application SOnar Trainer
MAT-CALS	Marine Air Traffic-Control And Landing System
MAU	Math Acceleration Unit
MAU	Media Access Unit
MAU	Medium Access Unit
MB	Manned Base [Space]
MB	MegaByte
MBA	Master Business Administration
MBTA	Massachusetts Bay Transportation Authority
MC	Master of Ceremonies
MCA	Micro Channel Architecture
MCAE	Mechanical Computer Aided Engineering
MCC	Master Control Console
MCC	Microelectronics and Computer technology Corporation
MCC	Mission Control Center [Space]
MCP	Master Control Program
MCP/AS	Master Control Program/Advanced System
MCPO	Master Chief Petty Officer
MCSV	Mars Crew Sortie Vehicle [NASA OEXP]
MD	Doctor of Medicine
MD	Maryland
MD	Maryland [US state postal designation]
MD	Medical Doctor
MD	Months after Date
MDAS	Magnetic Drum Auxiliary Sender
MDC	Metropolitan District Commision (Mass State Agency)
MDE	Modular Design Environment
MDF	Main Distribution Frame [Telephony]
MDRE	Mass Driver Reaction Engine [Space]
MDT	Mean Down Time
ME	Maine
ME	Mechanical Engineer
MECO	Main Engine CutOff [Space, Shuttle]
MEd	Master of EDucation
MERP	Middle-Earth Role Playing
MeV	Million Electron Volts
MF	Medium Frequency (300-3000KHz)
MF	Middle French
MF	Multi-Frequency [Telephony]
MFA	Master Fine Arts
MFA	Museum of Fine Arts [Boston]
MFJ	Modified Final Judgment [Telephony]
MFLOPS	Million FLoating-point OPerations per Second (see also FLOPS)
MFM	Modified Frequency Modulation
MFS	Macintosh File System
MG	Machine Gun
MG	Major General
MG	Military Government
MGH	Massachusetts General Hospital
MGM	Metro-Goldwyn Mayer [Corporate name]
MHD	MagnetoHydroDynamics
MHS	Mail Handling System [ISO]
MHz	Mega HertZ (unit of frequency, 1,000,000 cycles per second)
MI	Michigan
MI	Military Intelligence
MIA	Missing In Action
MIB	Management Information Base
MIDI	Musical Instrument Digital Interface
MIFASS	Marine Integrated Fire And Support System
MIM	Morality In Media
MIMD	Multiple Instruction, Multiple Data
MINCE	MINCE Is Not Complete Emacs
MINE	MINE Is Not Emacs (but it is mine)
MIPS	Million Instructions Per Second
Mir	Peace [Russian]
MIRV	Multiple Independently-Targetable Reentry Vehicle
MIS	Management Information System
MIT	Massachusetts Institute of Technology
ML	Middle Latin
mL	milliliter(s)
MLA	Member of Legislative Assembly (see MPP)
MLD	Minimum Lethal Dose
MLL	Mars Logistics Lander [NASA OEXP]
MLS	Microwave Landing System
MLS	Multi-Level Security
MLV	Medium Lift Vehicle [NASA OEXP]
MM	Maryknoll Missioners
mm	millimeters
MMES	Martin Marietta Energy Systems
MMFS	Manufacturing Message Format Standard
MMH	MonoMethyl Hydrazine [Space]
MMM	see 3M
MMT	Multiple Mirror Telescope [Space]
MMU	Manned Maneuvering Unit [Space]
MMU	Memory Management Unit
MMW	Multi-Mega Watt [Space]
MN	Minnesota
MNA	Member of National Assembly (Quebec)
MNP	Microcom Networking Protocol [Corporate name]
MNRAS	Monthly Notices of the Royal Astronomical Society [Space]
MO	Mail Order
MO	Medical Officer
MO	Missouri
MO	Modus Operandi
MO	Money Order
MOC	Mars Observer Camera (on Mars Observer) [Space]
MOD	Ministry of Defence (UK) (sometimes written MoD)
MOL	Manned Orbiting Laboratory [Space]
MOLA	Mars Observer Laser Altimeter (on Mars Observer) [Space]
MOMA	Museum of Modern Art [New York]
MOMV	Manned Orbital Maneuvering Vehicle [Space]
MOR	Middle-Of-the-Road
MOS	Metal Oxide Semiconductor
MOSFET	Metal Oxide Semiconductor Field Effect Transistor
MOTAS	Member Of The Appropriate Sex
MOTIS	Member Of The Inappropriate Sex
MOTIS	Message-Oriented Text Interchange System
MOTOS	Member of the Opposite Sex
MOTSS	Member of the Same Sex
MOTV	Manned Orbital Transfer Vehicle [Space]
MOU	Memorandum Of Understanding
MOUSE	Minimum Orbital Unmanned Satellite of Earth
MP	Melting Point
MP	Member of Parliament
MP	Metropolitan Police
MP	Military Police(man)
MPC	Minor Planets Circular [Space]
MPE	Mission to Planet Earth [Space]
MPG	Miles Per Gallon
MPH	Miles Per Hour
MPP	Member of Provincial Parliament (Canada; also MLA)
MPR	Mars Pressurized Rover [Space]
MPV	Mars Piloted Vehicle [NASA OEXP]
MPW	Macintosh Programmer's Workshop
MR	Miniatures Rules
MRI	Magnetic Resonance Imaging
MRP	Manufacturing Requirements Planning
MRSR	Mars Rover and Sample Return [Space]
MRSRM	Mars Rover and Sample Return Mission [Space]
MS	ManuScript
MS	Master of Science
MS	Military Science
MS	Motor Ship
MS	Multiple Sclerosis
MSB	Most Significant Bit; Most Significant Byte
MSC	MicroSoft C
MSCP	Mass Storage Control Protocol
MSD	Most Significant Digit
MS-DOS	MicroSoft DOS
MSE	Mobile Subscriber Equipment
MSFC	(George C.) Marshall Space Flight Center (NASA) [Space]
MSFC	Marshall Space Flight Center
MSG	MonoSodium Glutamate
MSH	Marvel Super Heroes
MSL	Mean Sea Level
MSPCA	Massachussetts Society for the Prevention of Cruelty to Animals
MSPE	Mercenaries, Spies & Private Eyes
MSRP	Manufacturer's Suggested Retail Price
MSS	Management Support System
MSS	ManuScriptS
MSS	Mass Storage System
MSS	Maximum Segment Size [TCP/IP] (see also MTU)
MST	Mountain Standard Time
MT	Metric Ton
MT	Mountain Time
MTA	Message Transfer Agent
MTA	Metropolitan Transportation Authority
MTBF	Mean Time Between Failures
MTC	Man Tended Capability [Space]
MTR	Magnetic Tape Recording
MTSO	Mobile Telephone Switching Office [Telephony]
MTTF	Mean Time To Failure
MTTR	Mean Time To Recovery
MTTR	Mean Time To Repair
MTU	Maximum Transfer Unit [Networking] (see also MSS)
MTV	Music TeleVision
MUF	Maximum Usable Frequency (max freq during sunspot activity)
MULTICS MULTiplex Information Computer Services
MUMPS	Mgh Utility MultiProgram System
MUNG	Mung Until No Good (see the hacker's dictionary)
MUX	MUltipleXor
MVA	MegaVolt Ampere
MVS	Multiple Virtual Storage [IBM]
MX	Missile eXperimental
N	North
N	Notice
NA	Narcotics Anonymous
NA	North America
NA	Not Applicable
NAACP	National Association for the Advancement of Colored People
NAAS	North American Automated Systems co.
NAB	National Association of Broadcasters
NABISCO NAtional BIScuit COmpany [Corporate name]
NACCIRN North American Coordinating Committee for Intercontinental Research Networking (see also CCIRN)
NACS	National Advisory Committee on Semiconductors
NAD	Network Access Device
NADGE	NATO Air Defense Ground Environment
NAFTA   North American Free Trade Agreement     
NAG	Numerical Algorithms Group
NAGE	National Association of Government Employees
NAK	Negative AcKnowledge
NAM	Name and Address Module [Telephony] (cellular phone changeable ROM)
NAM	National Account Manager [Telephony, AT&T]
NAM	Number Assignment Module [Telephony] (cellular phone changeable ROM)
NANP	North American Numbering Plan
NAPAP	National Acid Precipitation Assessment Program
NAR	Nuclear Acoustic Resonance
NARDAC	NAvy Regional Data Automation Center
NAS	National Academy of Sciences
NAS	National Advanced Systems
NASA	National (US) Aeronautics and Space Administration [Space]
NASDA	NAtional (Japan) Space Development Agency [Space]
NASM	National (US) Air and Space Museum [Space]
NASP	National (US) AeroSpace Plane [Space]
NATO	North Atlantic Treaty Organization
NAVDAC	NAVal Data Automation Command
NAVSWC	NAVal Surface Weapons Center
NB	New Brunswick
NB	Nota Bene
NBA	National (US) Basketball Association
NBC	National (US) Broadcasting Company [Corporate name]
NBFM	NarrowBand Frequency Modulation
NBO	Network Build Out
NBS	National Bureau of Standards (renamed NIST) [US Government]
NBVM	Narrow Band Voice Modulation
NC	No Charge
NC	No Connection
NC	North Carolina
NCA	Network Control Analysis
NCC	National (US) Computer Conference
NCC	National (US) Council of Churches
NCDC	National (US) Climatic Data Center
NCE	New Catholic Edition
NCGA	National (US) Computer Graphics Association
NCI	National (US) Cancer Institute [US Government]
NCIC	National (US) Cartographic Information Center
NCO	Non-Commissioned Officer
NCP	Network Control Program
NCR	National (US?) Cash Register [Corporate name]
NCS	Network Computing System
NCSA	National (US) Center for Supercomputing Applications
NCSC	National (US) Computer Security Center [NSA]
NCTL	National Computer and Telecommunications Laboratory
NCV	No Commercial Value
ND	No Date
ND	North Dakota
NDA	Non-Disclosure Agreement
NDDL	Neutral Data Definition Language
NDE	News Development Environment
NDEA	National (US) Defense Education Act
NDL	Network Database Language
NDP	New Democratic Party (Canada)
NDSL	National (US) Defense Student Loan
NDSL	National (US) Direct Student Loan
NDT	Newfoundland Daylight Time
NDV	NASP Derived Vehicle
NDV	NASP Derived Vehicle [Space]
NE	New England
NE	North East
NEAR	National Electronic Accounting and Reporting system
NEARnet New England Academic and Research Network
NEB	New English Bible
NEC	Nippon Electric Company [Corporate name]
NEI	Not Elsewhere Included
NES	National Energy Strategy
NES	Not Elsewhere Specified
NESC	National Energy Software Center
NET	National (US) Educational Television
NET	New England Telephone
NEWS	Network extensible Window System
NEXRAD	NEXt generation weather RADar
NF	No Funds
NFC	National (US) Football Conference
NFFE	National (US) Federation of Federal Employees
NFL	National (US) Football League
NFS	Network File System
NG	National Guard
NG	No Good
NGC	New General Catalog [Space]
NH	New Hampshire
NHI	National Health Insurance
NHL	National (Canada) Hockey League
NHLBI	National Heart, Lung, and Blood Institute (Bethesda, MD)
NIC	Network Information Center ("The NIC" is NIC.DDN.MIL)
NICMOS	Near Infrared Camera / Multi Object Spectrometer (HST upgrade) [Space]
NIFTP	(a file transfer network in the UK)
NIH	National (US) Institutes of Health
NIH	Not Invented Here
NIM	Nuclear Instrumentation Module (an electronic instr. standard)
NIMH	National Institute of Mental Health (Rockville, MD)
NIMS	Near-Infrared Mapping Spectrometer (on Galileo) [Space]
NIR	Near InfraRed [Space]
NIS	Network Information System (formerly yp)
NISO	National Information Standards Organization
NIST	National Institute of Standards and Technology (formerly NBS) [US Government]
NJ	New Jersey
NJB	New Jersey Bell [Telephony]
NL	National League (baseball)
NLM	National Library of Medicine
NLP	Natural Language Processing
NLRB	National Labor Relations Board
NLS	Network License Server
NM	Nautical Mile
NM	New Mexico
NM	Night Message
NM	No Mark; Not Marked
NMOS	N channel Metal Oxide Semiconductor (N-MOS) (see MOS)
NMR	Nuclear Magnetic Resonance
NMS	Network Monitoring Station
NNE	North North East
NNTP	Net News Transfer Protocol
NNW	North North West
NNX	NANP syntax for a three-digit string, N:{2-9}, X:{0-9} [Telephony]
NOA	NSWC Office Automation
NOAA	National Oceanic and Atmospheric Administration [Space, US Government]
NOAO	National (Tucson, AZ, US) Optical Astronomical Observatories [Space]
NOC	Network Operations Center
NORAD	NORth American Defense Command
NORM	Naturally Occuring Radioactive Material
NORML	National Organization for the Reform of Marijuana Laws
NOS	Not Otherwise Specified
NOSC	Naval Ocean Systems Center
NOTIS	Network Operator Trouble Information System
NOW	Negotiable Order for Withdrawal [Banking] (Is this MA or NE specific?)
NOx	Nitrogen Oxides
NP	No Protest
NP	Nondeterministic-Polynomial
NP	Notary Public
NP	Noun Phrase
NPA	Numbering Plan Area (area code) [Telephony]
NPC	Non-Player Character (see PC) [Role-playing]
NPL	National Physical Laboratory (UK)
NPL	Non-Procedural Language
NPN	Negative-Positive-Negative (transistor)
NPN	NonProtein Nitrogen
NPR	National Public Radio
NPR	non-Processor Request [PDP11, UNIBUS]
NQS	Network Queuing System
NRA	National Reconstruction Act (FDR era US)
NRA	National Rifle Association
NRAO	National Radio Astronomical Observatory [Space]
NRC	National Research Council
NRC	Nuclear Regulatory Commission
NRE	Non-Recurring Engineering (as in NRE costs)
NREN	National (US) Research and Education Network
NRL	Naval Research Labs
NRO	National Reconnaissance Office
NRO	National Reconnaissance Organization [Space]
NRZ	Non-Return to Zero
NRZI	Non-Return to Zero Inverted (magnetic tape, 800 bpi)
NS	Neutron Star [Space]
NS	Not Specified
NS	Nova Scotia
NS	Nuclear Ship
NSA	National Security Agency [US Government]
NSAP	Network Service Access Point [OSI, Networking]
NSC	National (US) Security Council [US Government]
NSE	Network Software Environment
NSF	National (US) Science Foundation [US Government]
NSS	Nodal Switching System [NSFnet]
NSSDC	National Space Science Data Center [Space]
NST	Newfoundland Standard Time
NSTS	National Space Transportation System [Space]
NSW	New South Wales (Australia)
NSWC	Naval Surface Warfare Center
NSWC	Naval Surface Weapons Center
NT	New Testament
NT	Newfoundland Time
NT	Northern Territory
NTEU	National Treasury Employees Union
NTIS	National Technical Information Service
NTN	Neutralized Twisted Nematic
NTP	Network Time Protocol [Internet]
NTP	Normal Temperature and Pressure (see STP)
NTSB	National Transportation Safety Board [US Government]
NTSC	National Television Standards Committee
NTSC	Never Twice Same Color
NTT	New Technology Telescope [Space]
NTT	Nippon Telephone & Telegraph
NU	Name Unknown
NURBS	NonUniform Rational B-Spline
NUSC	Naval Underwater Systems Center [US Government]
NV	Nevada
NW	North West
NWNET	NorthWestNet
NWS	National Weather Service
NWT	North West Territories (Australia)
NXX	NANP syntax for a three-digit string, N:{2-9}, X:{0-9} [Telephony]
NY	New York
NYC	New York City
NYNEX	New York and New England (Telephone)
NYPD	New York Police Department
NYSE	New York Stock Exchange
NYSERNet	New York State Educational and Research Network
NZ	New Zealand
NZUSUGI New Zealand Unix System User Group, Inc.
OA	Office Automation
OA	Overeaters Anonymous
OAO	Orbiting Astronomical Observatory [Space]
OAS	Organization of American States
OATS	Office Automation Technology and Services
OBE	Order of the British Empire
OBS	Omni Bearing Selector
OC	Order of Canada
OCDM	Office of Civil Defense and Mobilization
OCI	Out of City Indicator
OCLC	Online Computer Library Center, Inc.
OCLC	Online Computer Library Center (Ohio College Library Catalog)
OCO	Object Code Only
OCR	Optical Character Recognition
OCS	Officer Candidate School
OCST	Office of Commercial Space Transportation [Space]
OD	Doctor of Optometry
OD	Oculus Dexter (right eye)
OD	Officer of the Day
OD	OverDose
ODI	Optical Digital Image
ODISS	Optical Digital Image Storage System
ODT	Octal Debugging Technique
ODT	Online Debugging Technique
OE	Old English
OED	Oxford English Dictionary
OEM	Original Equipment Manufacturer
OEO	Office of Economic Opportunity
OES	Order of the Eastern Star
OEXP	Office of Exploration [NASA]
OF	Old French
OFM	Order of Friars Minor
OFS	Order of Free State
OG	Original Gum
OH	Ohio
OIRA	Office of Information and Regulatory Affairs
OIU	Office Interface Unit
OJT	On the Job Training
OLTP	On-Line Transaction Processing
OMB	Office of Management and Budget [US Government]
OMD	Orchestral Manouevers in the Dark
OMS	Orbital Maneuvering System [Space]
OMV	Orbital Maneuvering Vehicle [Space]
ON	Old Norse
ONC	Open Network Computing
ONI	Office of Naval Intelligence
ONI	Operator Number Identification [Telephony]
ONR	Office of Naval Research
OOP	Object Oriented Programming
OOPART	Out Of Place ARTifact
OOPS	Object-Oriented Programming System
OP	Observation Post
OP	OFFICEPOWER office automation system, trademark of CCI
OP	Order of Preachers
OP	Out of Print
OPEC	Organization of Petroleum Exporting Countries
OPF	Orbiter Processing Facility [Space]
OPM	Office of Personnel Management
OPUS	Obvious Password Utility System (Eugene Spafford )
OR	Operating Room
OR	Oregon
OR	Owner's Risk, Own Risk
ORFEUS	Orbiting and Retrievable Far and Extreme Ultraviolet Spectrometer [Space]
ORNL	Oak Ridge National Laboratory
OROM	Optical Read Only Memory
OS	Oculus Sinister (left eye)
OS	Operating System
OS	Ordinary Seaman
OS	Out of Stock
OSB	Order of St. Benedict
OSC	Orbital Sciences Corporation [Space]
OSCAR	Orbiting Satelite Carry Amateur Radio (1st launched 12 Dec 1961)
OSCAR	Orbiting Satellite Carry Amateur Radio (1st launched 12 Dec 1961)
OSCAR	Orbiting Satellite Carrying Amateur Radio [Space]
OSCRL	Operating System Command Response Language
OSD	Office of the Secretary of Defense
OSDIT	Office of Software Development and Information Technology
OSF	Open Software Foundation
OSF	Open Systems Foundation
OSF	Order of St. Francis
OSHA	Occupational Safety and Health Administration [US Government]
OSI	Office of Scientific Integrity [NIH]
OSI	Open Systems Interconnection (per ISO; 7 layer model)
OSI/RM	Open Systems Interconnection/Reference Model
OSME	Open Systems Message Exchange
OSP	Optical Storage Processor
OSPFIGP Open Shortest-Path First Internal Gateway Protocol [Internet]
OSS	Office of Strategic Services (later CIA)
OSS	Office Support System
OSS	Operation Support System [Telephony, AT&T]
OSSA	Office of Space Science and Applications [Space]
OSSE	Oriented Scintillation Spectrometer Experiment (on GRO) [Space]
OSTP	Office of Science and Technology Policy
OSTP	(White House) Office of Science and Technology Policy [US Government]
OT	Old Testament
OT	OverTime
OTA	Office of Technical Assistance
OTA	Office of Technology Assessment
OTA	Optical Telescope Assembly (on HST) [Space]
OTB	Off-Track Betting
OTC	Over The Counter (stocks)
OTF	Open Token Foundation
OTH-B	Over The Horizon - Backscatter (as in radar)
OT&LF	Open Taxi & Limousine Foundation
OTR	On The Rag
OTS	Officers' Training School
OTV	Orbital Transfer Vehicle [Space]
OUTWATS OUTward Wide Area Telephone Service [Telephony]
OV	Orbital Vehicle [Space]
OV	Orbiter Vehicle [Space]
PA	Pennsylvania
PA	Per Annum
PA	Play Aid
PA	Power of Attorney
PA	Press Agent
PA	Private Account
PA	Public Address
PA	Purchasing Agent
PABX	Private Automatic Branch eXchange [Telephony]
PACCOM	Pacific Computer Communications network consortium [Networking]
PACX	Private Automatic Computer eXchange
PAD	Packet Assembler-Disassembler [Networking]
PAH	Polycyclic Aromatic Hydrocarbon
PAL	Phase Alternation Line-rate
PAL	Programmable Array Logic
PAM	Payload Assist Module [Space]
PAM	Pulse Amplification Modulation
PARC	Palo Alto Research Center, xerox
PASS	Personal Access Satellite System [NASA]
PATROL	Program for Administrative Traffic Reports On Line
PBM	Play By Mail game
PBS	Public Broadcasting System
PBX	Private Branch eXchange [Telephony]
PC	Peace Corps
PC	PerCent; PerCentage
PC	Personal Computer (IBM wants you to believe a specific kind)
PC	Player Character (see NPC) [Role-playing]
PC	Politically Correct
PC	Post Card
PC	Post Cibum (after meals)
PC	Privileged Character
PC	Privy Council
PC	Program Counter
PC	Progressive Conservative party [Canada]
PC	Providence College
PC/AT	Personal Computer/Advanced Technology
PCB	PolyChlorinated Biphenyl
PCB	Printed Circuit Board
PC-DOS	Personal Computer DOS
PCI	Panel Call Indicator
PCIE	President's Council on Integrity and Efficiency
PCL	Printer Command Language
PCM	Plug-Compatible Mainframe
PCM	Pulse Code Modulation
PCMCIA	People Can't Memorize Computer Industry Acronyms
PCPC	Personal Computers Peripheral Corporation
PCS	Permanent Change of Station
PCTE	Portable Common Tools Environment
PCTS	Posix Conformance Test Suite
PD	Per Diem
PD	Police Department
PD	Potential Difference
PD	Public Domain
PDAD	Proposed Draft ADdendum
PDE	Partial Differential Equation
PDES	Product Data Exchange Specifications
PDF	Program Development Facility
PDL	Page Description Language
PDL	Program Design Language
PDN	Public Data Network
PDP	Plasma Display Panel
PDP	Programmed Data Processor
PDP	Programmed Data Processor [DEC]
PDQ	Pretty Damned Quick
PDS	Premises Distribution System [AT&T]
PDT	Pacific Daylight Time
PE	Phase Encoded
PE	Physical Education
PE	Prince Edward island
PE	Printer's Error
PE	Professional Engineer
PE	Protestant Episcopal
PEI	Prince Edward Island
PEP	Productivity Enhancement Project
PEPE	Pepe Est Presque Emacs
PERL	Pathologically Eclectic Rubbish Lister
PERL	Practical Extraction and Report Language
PEX	Phigs/phigs+ Extension to X
PFC	Plasma Fusion Center [MIT]
PG	Parental Guidance (suggested) [Movie rating]
PGA	Professional Graphics Adapter
PGA	Pure Grain Alcohol
PHA	Pulse Height Analyzer (or Analysis)
PHIGS	Programmers Hierarchical Interactive Graphics System
PHS	Public Health Service
PhysRev Physical Review Journal	  - Phys Rev
PI	Principal Investigator
PI	Priority Interrupt
PI	Private Investigator
PIC	Plastic/Polyethelene Insulated Cable [Telephony]
PIC	Position Independant Code
PIF	Paid In Full
PIT	Principal, Interest, and Taxes
PIXEL	PIcture ELement
PLA	Programmable Logic Array
PLATO	Programmed Learning for Automated Teaching Operations (U. Ill., early '70s)
PLC	Programmable Logic Controller
PLCC	Plastic Leaded Chip Carrier
PLL	Phase-Locked Loop
PLM	Programming Language for Microcomputers
PLO	Palestine (sic?) Liberation Organization (?)
PLO	Please Leave On
PLSS	Portable Life Support System [Space]
PM	PayMaster
PM	Police Magistrate
PM	Post Meridiem
PM	Post Meridiem (after noon)
PM	PostMaster
PM	PostMortem
PM	Pressurized Module [Space]
PM	Preventive Maintenance
PM	Prime Minister
PM	Provost Marshal
PMC	Permanently Manned Capability [Space]
PMIRR	Pressure Modulated InfraRed Radiometer (on Mars Observer) [Space]
PMO	Prime Minister's Office
PMOS	P channel Metal Oxide Semiconductor (P-MOS) (see MOS)
PMS	PreMenstrual Syndrome
PMT	PhotoMultiplier Tube
PM/X	Presentation Manager for X windows
PN	Promissory Note
PNP	Positive-Negative-Positive (transistor)
PO	Petty Officer
PO	Post Office
PO	Postal Order
PO	Purchase Order
POC	Port Of Call
POD	Pay On Delivery
POE	Port Of Embarkation
POE	Port Of Entry
POGO	Polar Orbiting Geophysical Observatory
POM	Phase Of Moon
POP	Point of Presence [Telephony]
POP	Post Office Protocol [Networking] (esp. TCP/IP)
POPS	Paperless Order Processing System
POR	Price On Request
POS	Point Of Sale
POS	Professional Operating System [DEC]
POSI	Promoting conference for OSI
POSIX	Portable Operating System for unIX
POSIX	Portable Operating System Interface
POTS	Plain Old Telephone Service [Telephony]
POTV	Personnel Orbit Transfer Vehicle [Space]
POV	Point Of View
POW	Prisoner Of War
PP	Parcel Post
PP	Past Participle
PP	Post Pay (payphone) [Telephony]
PP	Primary Point
PPB	Parts Per Billion
PPC	Pour Prendre Conge' (to take leave)
PPCS	Person to Person, Collect, Special [Telephony]
PPM	Parts Per Million
PPN	Parameterized Post-Newtonian formalism for general relativity
PPN	Project Programmer Number
PPP	Point-to-Point Protocol (successor to SLIP (q.v.))
pps	Packets per Second
PPS	PostPostScriptum
PPT	Parts Per Trillion
PPT	Pulse Pair Timing
PPT	Punched Paper Tape
PQ	Province of Quebec
PR	PayRoll
PR	Public Relations
PR	Puerto Rico
PRC	Planning Research Corporation
PREPnet Pennsylvania Research & Economic Partnership Network
PRI	Primary Rate Interface (ISDN) [Telephony]
PRN	pro re nata [Medicine] (as needed?)
PROFS	PRofessional OFfice System [IBM]
PROM	Programmable Read-Only Memory
PS	PicoSecond
PS	PostScript
PS	PostScriptum
PS	Power Steering
PS	Power Supply
PS	Proposed Standard
PS	Public School
PSA	Problem Statement Analyzer
PSC	Pittsburgh Supercomputer Center
PSC	Polar Stratospheric Clouds
PSDN	Public Switched Data Network [Telephony]
PSDS	Public Switched Digital Service [Telephony, AT&T]
PSE	Programming Support Environment
PSF	Point Spread Function [Space]
PSG	Platoon SerGeant
PSI	Performance Systems International [Corporate name, Networking]
PSI	Power Systems, Incorporated [Corporate name, Model Railroading]
PSK	Phase Shift Keying
PSL	Problem Statement Language
PSN	Packet Switch Node [ARPANET/MILNET] (replaced IMP)
PSR	Product Specific Realizations
PSR	PulSaR [Space]
PSS	(unknown to me, but something in the UK environment)
PST	Pacific Standard Time
PSTN	Public Switched Telephone Network
PT	Pacific Time
PT	Patrol Torpedo (as in PT boat)
PT	Physical Therapy
PT	Physical Training
PTA	Parent-Teacher Association
PTD	Parallel Transfer Disk
PTL	Praise The Lord (ministry)
PTN	Plant Test Number [Telephony] (actual number assigned for 800 service)
PTO	Patent and Trademark Office
PTO	Please Turn Over
PTO	Power Take-Off
PTT	Post, Telephone and Telegraph administration
PTV	Passenger Transport Vehicle [Space]
PUC	Public Utilities Commision
PV	Photovoltaic [Space]
PVC	Permanent Virtual Circuit (see also VC)
PVC	Poly-Vinyl Chloride
PVO	Pioneer Venus Orbiter [Space]
PW	Prisoner of War (usually POW)
PWG	Permanent Working Group
PX	Post eXchange (see BX)
QAM	Quadrature Amplitude Modulation
QC	Quality Control
QC	Queen's Counsel (KC when queen reigning)
QD	Quaque Die (daily) [Medicine]
QDA	Quantity Discount Agreement
QED	Quod Erat Demonstrandum (which was to be demonstrated) [Latin]
QEF	Quod Erat Faciendum (which was to be done) [Latin]
QEI	Quod Erat Inveniendum (which was to be found out) [Latin]
QET	Quantum Effect Transistor
QIC	Quarter-Inch Cartridge
QID	Quater In Die (four times a day) [Medicine]
QLI	Query Language Interpreter
QM	QuarterMaster
QMC	QuarterMaster Corps
QMF	Query Management Facility
QMG	QuarterMaster General
QMS	Quality Micro Systems [Corporate name]
QNS	Quantity Not Sufficient
QSO	Quasi-Stellar Object [Space]
q.v.	???? (Latin(?): which see)
QWERTY	first six keys from left on top alphabetic row of standard keyboard
R	Restricted [Movie rating]
R	Rolemaster
RA	Regular Army
RA	Research Assistant
RA	Royal Academy
RAAF	Royal Australian Air Force
RACE	Random Access Card Equipment
RACEP	Random Access and Correlation for Extended Performance 
RAD	Radiation Absorbed Dose
RAD	Rapid Access Disk
RADAR	RAdio Detection And Ranging
RADM	Rear ADMiral
RAF	Royal Air Force
RAM	Random Access Memory (R/W)
RAM	Red Academicia de Mexico (Mexican Academic Network)
RARDE	Royal Armaments Research and Development Establishment
RARE	R\'eseaux Associ\'es pour la Recherche Europ\'eenne (the European Organization of Research Networks)
RAS	Reliability, Availability, and Serviceability
RASC	Residence Account Service Center
RATS	Radio Amateur Telecommunications Society
R&B	Rhythm and Blues (commonly R and B)
RBC	Red Blood Count
RBI	Runs Batted In
RBOC	Regional Bell Operating Company
RC	Red Cross
RC	Regional Center
RC	Resistor-Capacitor circuit (as in filters)
RC	Roman Catholic
RCA	Radio Corporation of America [Corporate name]
RCAF	Royal Canadian Air Force
RCAS	Reserve Component Automation System
RCC	Radio Common Carrier
RCMP	Royal Canadian Mounted Police
RCS	Reaction Control System [Space]
R&D	Research and Development (commonly R and D)
RD	Rural Delivery
RDA	Remote Data Access
RDBMS	Relational DataBase Management System
RDF	Radio Direction Finding
REA	Rail Express Agency
RECON	Reconnaissance
REM	Rapid Eye Movement
REO	R. E. Olds
REO	Removable, Erasable, Optical
RETMA	Radio {something(equipment?)?} {something?} Manufacturers' Association (????)
REXX	Restructured EXtended eXecutor
RF	Radio Frequency
RF	Radio Frequency [Space]
RFC	Request For Comments (ala ARPA Internet)
RFD	Rehoboth (MA) Fire Department
RFD	Rural Free Delivery
RFI	Radio Frequency Interference
RFI	Radio Frequency Interference [Space]
RFP	Request for Proposal
RFQ	Request for Quote
RFS	Remote File System
RGB	Red Green Blue
RGP	Raster Graphics Processor
RH	Right Hand
RHC	Regional (Bell) Holding Company
RHS	Right Hand Side
RI	Rhode Island
RIACS	Research Institute for Advanced Computer Science (NASA)
RIACS	Research Institute for Advanced Computer Science [Space]
RIAS	Radio In the American Sector, berlin
RIF	Reading Is Fundamental
RIF	Reduction In Force
RILM	Repertoire International de Literature Musicale
RIP	Rest In Peace (or Requiescat In Pace : latin)
RIP	Routing Interchange Protocol
RIPE	R\'eseaux IP Europ\'eenne (European IP Networks) (of RARE, q.v.)
RISC	Reduced Instruction Set Computer
RITA	Recognition of Information Technology Achievement award
RJE	Remote Job Entry
RLC	Resistor Inductor Capacitor
RLG	Research Libraries Group
RLIN	Research Libraries Information Network (run by RLG (q.v.))
RLL	Run Length Limited
RMA	Radio Manufacturers' Association
RMA	Return Materials Authorization
RMATS	Remote Maintenance Administration and Traffic System [Telephony]
RMS	Remote Manipulator System [Space]
RMS	Richard M. Stallman
RMS	Root Mean Square
RMS	Royal Mail Ship
RN	Registered Nurse
RN	Royal Navy
RNA	RiboNucleic Acid
RNGC	Revised New General Catalog [Space]
RNZAF	Royal New Zealand Air Force
ROG	Receipt Of Goods
ROM	Range Of Motion [Medicine]
ROM	Read-Only Memory
ROM	Rupture Of Membrane (as in birth)
ROSAT	ROentgen SATellite [Space]
ROSE	RATS (q.v.) Open Systems Environment
ROSE	Remote Operations Service Entity (per ISO/CCITT layer 7)
ROTC	Reserve Officers' Training Corps
ROTS	Rotary Out Trunks Selectors
ROYGBIV Red, Orange, Yellow, Green, Blue, Indigo, Violet
RPC	Remote Procedure Call
RPG	RePort Generator
RPG	Role Playing Game
RPI	Rensselaer Polytechnic Institute
RPM	Revolutions Per Minute
RPN	Reverse Polish Notation
RPO	Railway Post Office
RPS	Revolutions Per Second
RPV	Remotely Piloted Vehicle
RQ	RuneQuest
RR	RailRoad
RR	Route Relay
RR	Rural Route
RRO	Rate and Route Operator [Telephony]
RS	Recommended Standard (EIA)
RS	Recording Secretary
RS	Revised Status
RS	Right Side
RS	Royal Society
RSCS	Remote Spooling Communications Subsystem
RSFSR	Russian Soviet Federated Socialist Republic
RSN	Real Soon Now
RSU	Remote Switching Unit
RSV	Revised Standard Edition
RSVP	Repondez S'il Vous Plait (please reply)
RSWC	Right Side up With Care
RT	RadioTelephone
RT	RealTime
RTA	Remote Trunk Arrangement [Telephony]
RTAC	Regional Technical Assistance Center [Telephony]
RTF	Rich Text Format
RTFM	Read The @!# Manual
RTFM	Read The F***ing Manual
RTG	Radioisotope Thermoelectric Generator
RTG	Radioisotope Thermoelectric Generator [Space]
RTLS	Return To Launch Site (Shuttle abort mode) [NASA, Shuttle, Space]
RTR	Ready to Run [Model Railroading]
RTR	Reel-To-Reel
RTS	Request To Send (EIA RS-232-C)
RTTY	Radio Teletype
RU	Receive Unit
RVD	Remote Virtual Disk [MIT]
RW	Right Worshipful
RW	Right Worthy
RX	Receive
Ry	Railway
S	South
S	Supplement
SA	Salvation Army
SA	Seaman Apprentice
SA	Service Assistant
SA	Sex Appeal
SA	Sine Anno (without date)
SA	South Africa
SA	South America
SA	Subject to Approval
SAA	South Atlantic Anomaly
SAA	South Atlantic Anomaly [Space]
SAA	Systems Application Architecture
SAC	Special Area Code [Telephony] (represent services, not places)
SAC	Strategic Air Command (see TAC)
SAC	Strategic Air Command [US military]
SADD	Students Against Drunk Driving
SAFENET Survivable Adaptable Fiberoptic Embedded Network [US Navy]
SAM	Surface to Air Missile
SAM	Surface-to-Air Missile
SAMA	Step-by-step Automatic Message Accounting [Telephony]
SAMPEX	Solar Anomalous and Magnetospheric Particle EXplorer [Space]
SAMTO	Space And Missile Test Organization [Space]
SAO	Smithsonian Astrophysical Observatory [Space]
SAP	Second Audio Program
SAP	Service Access Point [OSI, Networking]
SAR	Search And Rescue
SAR	Synthetic Aperture Radar
SARA	Satellite pour Astronomie Radio Amateur [Space]
SARA	Stichting Academisch Rekencentrum Amsterdam (Amsterdam Universities Computing Center)
SAREX	Search and Rescue Exercise [Space]
SAREX	Shuttle Amateur Radio Experiment [Space]
SARTS	Switched Access Remote Test System
SAS	Small Astronomy Satellite
SAS	Space Activity Suit [Space]
SASE	Self-Addressed Stamped Envelope
SASI	Shugart Associates Systems Interface
SAT	Satellite [Space]
SAW	Surface Acoustic Wave
SBA	Small Business Administration
SC	Secondary Channel
SC	Sectional Center
S&C	Skull & Crossbones
SC	South Carolina
S/C	SpaceCraft [Space]
SC	SubCommittee
SCA	Shuttle Carrier Aircraft [Space]
SCAD	Subsonic Cruise Armed Decoy
SCADC	Standard Central Air Data Computer
SCAME	SCreen oriented Anti-Misery Editor
SCAMP	Single-Chip A-series Mainframe Processor
SCAN	Switched Circuit Automatic Network
SCC	Specialized Common Carriers
SCC	Switching Control Center
SCCS	Source Code Control System
SCE	Signal Conversion Equipment
SCE	Structure Chart Editor
SCI	SpaceCraft Incorporated
SCIFI	SCIence FIction (often used pejoratively of what really isn't)
SCO	Santa Cruz Operation
SCOOPS	SCheme Object Oriented Programming System
SCOTS	Surveilance and Control Of Transmission Systems
SCSI	Small Computer Systems Interface
SCT	Schmidt-Cassegrain Telescope [Space]
SCUBA	Self Contained Underwater Breathing Apparatus
SCUD	Subsonic Cruise Unarmed Decoy
SD	South Dakota
SDB	Source(?) DeBugger
SDI	Standard Disk Interconnect [DEC]
SDI	Strategic Defense Initiative [Space, US Government]
SDIO	Strategic Defense Initiative Organization [Space, US Government]
SDLC	Synchronous Data Link Control [IBM]
SDM	Sub-rate Data Multiplexer
SDN	Software Defined Network [Telephony, AT&T]
SDN	System Development Network (Korea)
SDO	Staff Duty Officer 
SDSC	San Diego Supercomputer Center
SDV	Shuttle Derived Vehicle [Space]
SE	Service Engineer (see also CE, FE)
SE	South East
SEATO	SouthEast Asia Treaty Organization
SECAM   Systeme Electronique Couleur Avec Memoire (Television standard in France, Greece, and Iraq).
SEC	Security Exchange Commission
SECNAV	SECretary of the NAVy
SED	Stream EDitor
SEI	Software Engineering Institute (Carnegie Mellon)
SEI	Space Exploration Initiative [Space]
SEL	Software Engineering Laboratory
SEM	Scanning Electron Microscope
SEST	Swedish-European Submillimeter Telescope [Space]
SETI	Search for Extra Terrestrial Intelligence [Space]
SETI	Search for ExtraTerrestrial Intelligence [Space]
SF	San Francisco
SF	Science Fiction; Speculative Fiction
SF      Scuderia Ferrari                       
SF	Standard Form
SF	Star Frontiers
SF      Supreme Fascist
SFRPG	Science Fiction Role Playing Game
SG	StarGuard
SG	SubGroup
SGML	Standard Generalized Markup Language
SHAPE	Supreme Headquarters Allied Powers Europe
SHAR	SHell ARchiver
SHCD	Sherlock Holmes Consulting Detective
SHF	Super High Frequency (3-30GHz)
SHRPG	Super Hero Role Playing Game
SI	Staten Island
SIAM	Society for Industrial and Applied Mathematics
SID	Sudden Ionospheric Disturbance [Space]
SIG	Special Interest Group
SIGCAT	Special Interest Group for Cd-rom Applications Technology
SIMD	Single Instruction, Multiple Data
SIMM	Single In-line Memory Module
SIMM	System Integrated Memory Module
SIPS	Satellite Imagery Processing System
SIR	Shuttle Imaging Radar [Space]
SIRTF	Space (formerly Shuttle) InfraRed Telescope Facility [Space]
SIRTF	Space Infrared Telescope Facility [Space]
SIS	Strategic Information System
SISCOM	Satellite Information System COMpany
SITA	Societe Internationale Telecommunications Aeronautiques
SJ	Society of Jesus
Skyhook Surface to space "elevator" transportation system [Space]
SL	Salvage Loss
SL	Space Launch [Space]
SL	SpaceLab [Space]
SLA	Special Libraries Association
SLA	Synchronous Line Adapter
SLAC	Stanford Linear Accelerator Center
SLAN	Sine Loco, Anno, (vel) Nomine (without place, year, or name)
SLAR	Side Looking Airborne Radar
SLAR	Side-Looking Airborne Radar [Space]
SLBM	Submarine Launched Ballistic Missiles
SLC	Space Launch Complex [Space]
SLC	Subscriber Loop Carrier [Telephony]
SLDC	Synchronous Data Link Control
SLIP	Serial Line Internet Protocol
SLIP	Serial Line IP (sometimes SL/IP) (see also PPP)
SLP	Super Long Play (VHS VCR)
SLS	Space(lab) Life Sciences [Space]
SM	Service Mark
SMA	Sergeant Major of the Army
SMA	Spectrum Manufacturers Association
SMC	Small Magellanic Cloud (see LMC)
SMC	Small Magellanic Cloud [Space]
SMD	Storage Module Device (interface standard for disk drives)
SMD	Surface Mounted Devices
SMDR	Station Message Detail Recording [Telephony]
SMDS	Switched Multi-megabit Data Service [Telephony, Networking]
SME	Solar Mesosphere Explorer [Space]
SMEGMA	Sophisticated Modern Editor with Gloriously Magnificent Abilities
SMERSH	Abbr. of Russian phrase meaning "Death to the spies."
SMEX	SMall EXplorers [Space]
SMILS	Sonobuoy Missile Impact Location System
SMM	Solar Maximum Mission (satellite 1980-1989) [Space]
SMTP	Simple Mail Transfer Protocol
SMU	Southeastern Massachusetts University
SMU	Southern Methodist University
SN	Science News [Periodical]
SN	Serial Number
SN	Super Nova
SN	SuperNova (e.g., SN1987A) [Space]
SNA	Systems Network Architecture [IBM]
SNADS	SNA Distribution Services
SNAFU	Situation Normal -- All Fouled Up (also more profane versions)
SNAP	Shipboard Non-tactical Automated data Processing program
SNAP	Sub Network Access Protocol [OSI, Networking]
SNCF	Societe National des Chemins de Fer (French National Railways)
SNF	Server-Natural Format
SNMP	Simple Network Management Protocol [TCP/IP]
SNOBOL	StriNg Oriented symbOLic Language
SNPA	SubNetwork Point of Attachment
SNR	Signal to Noise Ratio
SNR	Signal to Noise Ratio [Space]
SNR	SuperNova Remnant [Space]
SNU	Solar Neutrino Units [Space]
SO	Seller's Option
SO	Significant Other
SO	Space Opera
SO	Strike Out
SOAP	Symbolic Optimizing Assembler Program
SOFIA	Stratospheric Observatory For Infrared Astronomy [Space]
SOH	Start Of Header, ASCII control character (dec=01,control-A)
SOHIO	Standard Oil of oHIO [Corporate name]
SOHO	SOlar Heliospheric Observatory [Space]
SOL	Short on Landing (or, colloquially, Shit Out of Luck)
SONAR	SOund Detection And Ranging
SONET	Synchronous Optical Network [Telephony]
SOP	Standard Operating Procedure
SOS	Save Our Souls (International standard distress call, Morse ...---...)
SOS	Silicon On Sapphire
SOS	Son of Stopgap (editor) [DEC]
SOT     Sound on Tape
SP	Shore Patrol
SP	Short Play (VHS VCR)
s.p.	sine prole (Latin: without issue) [Genealogy]
SP	Southern Pacific [Corporate name, Railroading]
SP	Stack Pointer
SP	Star Patrol
SPA	Software Publishers Association
SPAG	Standards Promotion and Applications Group
SPAN	Space Physics and Analysis Network [NASA] (DECnet)
SPAN	Space Physics and Analysis Network [Space]
SPAR	Stock Points Adp Replacement
SPARC	Scalable Processor ARChitecture
SPARC	Standards, Planning, And Requirements Committee
SPAWAR	naval SPAce and WARfare command
SPC	Software Productivity Consortium
SPCA	Society for the Prevention of Cruelty to Animals
SPCC	Society for the Prevention of Cruelty to Children
SPDM	Special Purpose Dextrous Manipulator [Space]
SPEC	Systems Performance Evaluation Cooperative
SPITBOL SPeedy ImplemenTation of snoBOL
SPNI	Society for the Protection of Nature in Israel
SPOT	Systeme Probatoire pour l'Observation de la Terre [Space]
SPS	Solar Power Satellite [Space]
SPUR	Systech Pluraxial Unplug Repeater
SQE	Signal Quality Error (IEEE 802.3, eqv to D/I/X "Collision Presence Test") [Ethernet]
SQIID	Simultaneous Quad Infrared Imaging Device (at NOAO)
SQL	Structured Query Language
SQUID	Superconducting QUantum Interference Device
SRAM	Short Range Attack Missile
SRB	Solid (fuel) Rocket Booster [Space]
SRG	Short and Ring Ground (test) [Telephony]
SRI	Stanford Research Institute
SRM	Solid Rocket Motor [Space]
SRO	Standing Room Only
SS7	Signalling System #7 [Telephony]
SSA	Social Security Administration [US Government]
SSB	Single Side Band
SSC	Superconducting Super Collider
SSE	South-SouthEast
SSF	Space Station Fred (er, Freedom) [Space]
SSF	Space Station Freedom [NASA, Space]
SSFF	Showcase Software Factory of the Future
SSG	Staff SerGeant
SSI	Small Scale Integration
SSI	Solid-State Imager (on Galileo) [Space]
SSI	Space Services Incorporated [Corporate name, Space]
SSI	Space Studies Institute [Space]
SSI	Supplemental Security Income
SSME	Space Shuttle Main Engine [Space]
SSPF	Space Station Processing Facility [Space]
SSPS	Satellite Solar Power Station [Space]
SSR	Secondary Surveillance Radar
SSR	Soviet Socialist Republic
SSRMS	Space Station Remote Manipulator System [Space]
SST	Spectroscopic Survey Telescope [Space]
SST	SuperSonic Transport [Space]
SSTO	Single Stage To Orbit [Space]
SSTV	Slow Scan TeleVision
SSW	South-SouthWest
ST	Short Ton
STARS	Software Technology for Adaptable, Reliable Systems
STD	Sacrae Theologiae Doctor (doctor of sacred theology)
STD	Sexually Transmitted Disease (replaces VD)
STD	State Transition Diagram
STD	Subscriber Trunk Dialing (British, and elsewhere; equiv. DDD in USA)
STI	Standard Tape Interconnect [DEC]
STILO	Scientific and Technical Intelligence Liaison Office
STIS	Space Telescope Imaging Spectrometer (to replace FOC and GHRS) [Space]
STL	St. Louis (airport designation)
STN	SuperTwisted Nematic
STOL	Short TakeOff and Landing
STP	Shielded Twisted Pair [Telecom, Networking]
STP	Software Through Pictures
STP	Standard Temperature and Pressure (see NTP)
STRPG	Star Trek:  The Role-Playing Game
STS	Space Transportation System (space shuttle) [NASA]
STScI	Space Telescope Science Institute [Space]
STV	Single Transferable Vote
STV	Space Transfer Vehicle [Space]
SUM	Symantec Utilities for Macintosh
SUN	Stanford University Network
SUN	SUN MicroSystems Computer (not an Acronym) [Corporate name]
SUNOCO	SUN Oil COmpany [Corporate name]
SUNY	State University of New York
SURAnet Southeastern Universities Research Association Network
SVID	System V Interface Definition
SW	South West
SW	SuperWorld
SWAS	Submillimeter Wave Astronomy Satellite [Space]
SWBT	South Western Bell Telephone [Telephony]
SWF	ShortWave Fading [Space]
SWIFT	Society for Worldwide Interbank Financial Communications
SWS	Scientific Workstation Support
SXS	Step by Step switching [Telephony]
T	Traveler
T1	1.544Mbps [Telephony], one of the basic signalling systems 24x64Kb
T3	45Mbps (eq 28 T1 channels) [Telephony]
TA	Teaching Assistant
TAC	Tactical Air Command (see SAC)
TAC	Terminal Access Controller [ARPANET/MILNET] (replaced TIP)
TACACS	Terminal Access Controller Access Control System [ARPANET/MILNET]
TACCS	Tactical Army Combat service support Computer System
TAE	Transportable Applications Environment
TAKS    Texas Assessment of Knowledge and Skills
TAL	Trans-Atlantic Abort Landing [NASA, Shuttle]
TAL	Transatlantic Abort Landing (Shuttle abort plan) [Space]
TANSTAAFL	There Ain't No Such Thing As A Free Lunch
TAR	Tape ARchiver
TASI	Time Assign{ment,ed} Speech Interpolation [Telephony]
TAU	Thousand Astronomical Units [Space]
TB	TuBerculosis
TBA	To Be Announced
TBD	To Be Determined
TBD	To Be Done
TC	Teachers College
TCA	Terminal Controlled Airspace
TCP	Transmission Control Protocol
TCP/IP	Transmission Control Protocol/Internet Protocol
TCS	Thermal Control System [Space]
TCSEC	Trusted Computer System Evaluation Criteria (orange book)
TCT	To Challenge Tomorrow
TD	Tardive Dyskinesia
TD	TouchDown
TD	Treasury Department
TDCC	Transportation Data Coordinating Committee
TDE	Transition Diagram Editor
TDI	Trusted Database Interpretation
TDM	Time-Division Multiplexer
TDR	Time Domain Reflectometer
TDRS	Tracking and Data Relay Satellite [Space]
TDRSS	Tracking and Data Relay Satellite System [Space]
TDY	Temporary DutY
TECO	Tape Editor and COrrector
TECO	Text Editor and COrrector
TEFLON	polyTEtraFLuOrethyleNe
TEKS    Texas Essential Knowledge and Skills
TES	Thermal Emission Spectrometer (on Mars Observer) [Space]
TFP	Tops Filing Protocol
TFS	Translucent File System
TFT	The Fantasy Trip
TFT	Thin Film Transistor
TG	Thieves' Guild
TGV	Tres Grande Vitesse (French, Very High Speed) [Railroading]
TGV	Two Guys and a VAX (humorous variant) [Corporate name]
THIEF	THief Isn't Even Fine
THIEF	This Here Isn't Even Fine
THOR	Tandy High-intensity Optical Recording
TI	Texas Instruments
TIA	Thanks In Advance [Net jargon]
TIA	Transient Ischemic Attack
TIC	TermInfo Compiler
TID	Ter In Die (three times a day)
TID	Transaction ID
TIFF	Tag Image File Format
TIP	Terminal Interface Processor [ARPANET/MILNET] (replaced by TAC)
TIS	Trusted Information Systems [Corporate name]
TISN	Tokyo International Science Network (Japan)
TKO	Technical Knock Out [Boxing]
TL	Total Loss
TLA	Three Letter Acronym
TLC	Tender Loving Care
TLI	Transort-Level Interface
TM	TradeMark
TMA	Tycho Magnetic Anomaly (movie 2001)
TMAC	Treasury department's Multiuser Acquisition Contract
TMIS	Telecommunications Management Information System
TMO	Telephone Money Order
TMP	The Morrow Project
TMRC	Tech Model Railroad Club [MIT]
TMRC	Transportation Modeling Research Center (TMRC {above} alter ego)
TN	Tennessee
TN	Twisted Nematic
TNC	Threaded Neill Concelman (connector) [Electronics] (see also BNC)
TNF	Tumor Necrosis Factor [Biology, Medicine]
TNP	Tech Nickel Plate (RR) [TMRC]
TNT	TriNitro Toluene
TO	Telegraph Office
TO	Turn Over
TODS	Transactions on Database Systems (ACM)
TOMS	Total Ozone Mapping Spectrometer [Space]
TOMS	Transactions on Mathematical Software (ACM)
TOOIS	Transactions on Office Information Systems (ACM)
TOP	Technical Office Protocol
TOPLAS	Transactions on Programming Languages and Systems (ACM)
TOPS	Traffic Operator Position System [Telephony]
TOPSMP	Traffic Operator Position System Multipurpose [Telephony]
TORES	Text ORiented Editing System
TOS	Transfer Orbit Stage [Space]
TOW	Tube launched, Optically tracked, and Wire guided
TOY	Time Of Year (clock)
TP	Transaction Processing
TP	Transport Protocol (ISO/CCITT Transport Services (TP0-TP4); like TCP)
TP4	Transport Protocol, class 4 [ISO]
TPC	The Phone Company (from classic movie: _The President's Analyst_)
TPI	Tracks Per Inch
TPO	Traveling Post Office
TPP	TetraarylPorPhyrin
TPS	Technical Publishing Software
TPS	TeleProcessing Services
TPS	Thermal Protection System [Space]
TR	Tech Report (at least at LCS (q.v.), maybe others)
TR	Technical Reference [Bell, Telephony]
TRG	Tip and Ring Ground (test) [Telephony]
TROFF	Text RunOFF, text formatter
TRW	Thompson, Ramo, and Woolridge
TS	Top Secret
TSAP	Transport Service Access Point [OSI, Networking]
TSD	Total System Design
TSP	Teleprocessing Services Program
TSP	Thrift Savings Plan
TSP	Time Synchronization Protocol
TSP	TriSodium Phosphate
TSR	TSR (Fortune 500 Company that manufactures Dungeons & Dragons)
TSS	Tethered Satellite System [Space]
TSTO	Two Stage to Orbit [Space]
T&T	Tunnels & Trolls
TTFN	Tah Tah, For Now
TTL	Transistor Transistor Logic
TTMA	Tennessee Tech Microcomputer Association
TTU	Tennessee Technological University
TTY	TeleTYpe
TUNIS	Toronto UNIversity System
TV	TeleVision
TVA	Tennessee Valley Authority
TW	Thieves' World
TWA	Trans World Airlines [Corporate name]
TWA	Three Word Acronym (submitted by Jarno)
TWB	Terrestrial WideBand [Networking, DARPA]
TWIMC	To Whom It May Concern
TWT	Traveling Wave Tube
TWX	TeletypeWriter eXchange
TX	Texas
Tx	Transmit
u	(representing the greek mu) - micro
U	Universe
UA	United Artists
UAR	United Arab Republic
UAR	User Action Routine
UARS	Upper Atmosphere Research Satellite [Space]
UART	Universal Asynchronous Receiver Transmitter
UBA	UniBus Adapter [DEC]
UBC	Universal Bibliographic Control
UBC	University of British Columbia
UBM	Unpressurized Berthing Mechanism [Space]
UCAR	University Corporation for Atmospheric Research
UCB	University of California at Berkeley
UCD	Uniform Call Distributor [Telephony]
UCD	University of California at Davis
UCI	University of California at Irvine
UCL	University College London
UCLA	University of California at Los Angeles
UCR	University of California at Riverside
UCSB	University of California at Santa Barbara
UCSC	University of California at Santa Cruz
UCSD	University of California at San Diego
UCSF	University of California at San Francisco
UDB	Unified DataBase
UDMH	Unsymmetrical DiMethyl Hydrazine [Space]
UDP	User Datagram Protocol
UEC	User Environment Component
UFO	Unidentified Flying Object [Space]
UGC	Uppsala General Catalog [Space]
UH	Upper Half
UHF	Ultra High Frequency (300-3000MHz)
UID	Unique IDentifier
UID	User IDentification [UNIX]
UIMS	User Interface Management System
UIT	Ultraviolet Imaging Telescope (Astro package) [Space]
UIUC	University of Illinois at Urbana-Champaign
UK	United Kingdom
UKST	United Kingdom Schmidt Telescope [Space]
UL	Underwriters Laboratory
ULANA	Unified Local-Area Network Architecture
UMOC	Ugliest Man On Campus [MIT]
UMT	Universal Military Training
UN	United Nations
UNESCO	United Nations Educational, Scientific, & Cultural Organization
UNICEF	United Nations International Children's Emergency Fund (now United Nat. Child. Fund)
UNICS	UNiplex Information Computer Services
UNIX	Not an acronym at all.	Was a joke on MIT's MULTICS.
UNMA	Unified Network Management Architecture [AT&T]
UNO	United Nations Organization
UP	Union Pacific [Railroading, Corporate name]
UPC	Universal Product Code
UPI	United Press International
UPI	United Press International [Corporate name]
UPS	Uninterruptible Power Supply
UPS	United Parcel Service [Corporate name]
UR	University of Rochester
URI	University of Rhode Island
US	United States (of America)
USA	Union of South Africa
USA	United States Army
USA	United States of America
USAF	United States Air Force
USAFA	United States Air Force Academy (in Colorado Springs)
USAN	University Satellite Network
USB	Upper Side Band
USC	University of Southern California
USCG	United States Coast Guard
USDA	United States Department of Agriculture
USES	United States Employment Service
USFL	United States Football League
USGS	United States Geological Survey
USIA	United States Information Agency
USM	United States Mail
USMC	United States Marine Corps
USMP	United States Microgravity Payload [Space]
USN	United States Navy
USO	United Service Organizations
USO	Unix Software Operation
USP	United States Pharmacopeia
USPS	United States Postal Service
USR	User Service Routines
USS	United States Ship
USSR	Union of Soviet Socialist Republics
USSS	User Services and Systems Support
USW	Und So Weiter
UT	Universal Time (a.k.a. GMT, UTC, or Zulu Time)
UT	University of Tennessee
UT	University of Texas
UTC	Coordinated Universal Time (a.k.a. UT)
UTC	Universal Coordinated Time (a.k.a. UT)
UTnet	University of Texas Network
UTP	Unshielded Twisted Pair [Telecom, Networking]
UUCP	UNIX-to-UNIX Copy Program
UUG	Unix User Group
UV	UltraViolet
UVS	UltraViolet Spectrometer
UW	UnderWriter
UW	Univ of Wisconsin
VA	Veterans Administration
VA	Virginia
VAB	Vehicle Assembly Building (formerly Vertical Assembly Building) [Space]
VAFB	Vandenberg Air Force Base [Space]
VAN	Value Added Network (e.g. Tymnet, Telenet, etc)
VANS	Value-Added Network Services
VAR	Value Added Remarketer (reseller)
VASI	Visual Approach Slope Indicator
VAT	Value Added Tax
VAX	Virtual Address eXtended
VAXBI	VAX Bus Interconnect
VC	Viet Cong
VC	Virtual Circuit
Vcc	Voltage (Common Cathode?)
VCM	Voice Coil Motor
VCO	Voltage Controlled Oscillator
VCR	VideoCassette Recorder
VCU	Virginia Commonwealth University
VD	Venereal Disease (see also STD)
VDFM	Virtual Disk File Manager
VDI	Virtual Device Interface
VDM	Vienna Development Method
VDM	Virtual Device Metafile
VDT	Video Display Terminal
VEEGA	Venus-Earth-Earth Gravity Assist (Galileo flight path) [Space]
VF	Video Frequency
VF	Voice Frequency
VFO	Variable Frequency Oscillator
VFR	Visual Flight Rules [Aviation]
VFW	Veterans of Foreign Wars
VFW	Volunteer Fire Department
VG	Very Good
VG	Vicar-General
VGA	Video Graphics Array
Vgg	Voltage (Gate to Ground?)
V&H	Vertical and Horizontal (CO coordinate tape) [Telephony]
VHDL	Vhsic Hardware Description Language
VHF	Very High Frequency (30-300MHz)
VHS	Video Home System (VCR)
VHSIC	Very High Speed Integrated Circuit
VI	VIsual editor
VIABLE	Vertical Installation Automation BaseLinE
VILE	VI Like Emacs
VINE	Vine Is Not Emacs
VIP	Very Important Person
VISTA	Volunteers In Service To America
VITA	Vme International Trade Association
VJ	Video Jockey
VL	Vulgar Latin
VLA	Very Large Array [Space]
VLBA	Very Long Baseline Array [Space]
VLBI	Very Long Baseline Interferometry [Space]
VLF	Very Low Frequency (3-30KHz)
VLIW	Very Long Instruction Word
VLSI	Very Large Scale Integration
VLT	Very Large Telescope [Space]
VM	Virtual Memory
VM/CMS	Virtual Machine/Conversational Monitor System
VMM	Virtual Memory Manager
VMOS	Vertical Metal Oxide Semiconductor (V-MOS) (see MOS)
VMR	Vertical Market Reseller
VMS	Vertical Motion Simulator [Space]
VMS	Virtual Memory System [DEC]
VO      Voice Over
VOA	Voice Of America
VOIR	Venus Orbiting Imaging Radar (superseded by VRM) [Space]
VOIS	Voice-Operated Information System
VOQ	Visiting Officer's Quarters
VPI&SU	Virginia Polytechnic Institute and State University
VRC	Vertical Redundancy Character
VRM	Venus Radar Mapper (now called Magellan) [Space]
VRM	Virtual Resource Manager
VSAT	Very Small Aperture Terminal (satellite dish)
VSX	X/open Verification Suite
VTAM	Virtual Telecommunications Access Method [IBM]
VTOC	Volume Table Of Contents
VTOL	Vertical TakeOff and Landing
VTR	VideoTape Recorder
VUP	Vax Unit of Performance
V&V	Villains & Vigilantes
VVSS	Vertical Volute Spring Suspension
W	West
W	Width
WA	Washington
WA	Western Australia
WAC	Womens Air Corps
WAIS	Wide Area Information Server
WARC	World Administrative Conference
WATS	Wide Area Telephone Service
WB	Water Ballast
WB	WayBill
WBC	White Blood Cells
WC	Water Closet
WC	Without Charge
WCTU	Women's Christian Temperance Union
WD	White Dwarf [Space]
w.d.	will dated [Genealogy]
WECo	Western Electric Company [AT&T] (manufacturing arm of AT&T)
WFPC	Wide Field / Planetary Camera (on HST) [Space]
WFPCII	Replacement for WFPC [Space]
WG	Working Group
WH	WarHammer
WHBL	World Home Bible League
WHCA	White House Communications Agency [US Government]
WHO	World Health Organization
WI	Wisconsin
WIMP	Windows/Icons/Mouse Programming(?)
WIPP	(nuclear) Waste Isolation Pilot Plant [DOE]
WIS	WWMCCS Information System
WITS	Washington Interagency Telecommunications System
WIYN	Wisconsin / Indiana / Yale / NOAO telescope [Space]
WMD	Weapons of Mass Destruction
WMSCR	Weather Message Switching Center Replacement
WOM	Write Only Memory
WOP	WithOut Papers [Immigration]
WOPR	War Operations Planned Response (from "Wargames" movie)
WORM	Write Once, Read Many times
WOW	Worlds of Wonder
w.p.	will proved [Genealogy]
WP	Word Processing
WP	Working Paper
WPI	Worcester Polytechnic Institute
WSI	Wafer Scale Integration
WSMR	White Sands Missile Range [Space]
WSW	West-SouthWest
WTR	Western Test Range [Space]
WU	Washington University
WU	Western Union
WUPPE	Wisconsin Ultraviolet PhotoPolarimter Experiment (Astro package) [Space]
WV	West Virginia
WW	World War
WWI	World War I
WWII	World War II
WWMCCS	World-Wide Military Command and Control System
WY	Wyoming
WYSIWIS What You See Is What I See
WYSIWYG What You See Is What You Get
XCF	eXperimental Computing Facility
XD	without Dividend
XDR	eXternal Data Representation
XFER	Transfer
XL	eXtra Large
XMM	X-ray Multi Mirror [Space]
XMTR	transMiTteR (the X is for trans)
XNS	Xerox Network Services
XO	eXecutive Officer
XOR	eXclusive OR (logical function)
XPORT	Transport
XSECT	cross SECTion
XTAL	crysTAL (another version of x for crys, see XMTR)
XUI	X-windows User Interface
XUV	eXtreme UltraViolet [Space]
YA	Yet Another
YACC	Yet Another Compiler Compiler
YB	YearBook
YMCA	Young Mens Christian Association
YMHA	Young Mens Hebrew Association
YOB	Year Of Birth
YP	Yellow Pages
YRS	Ysgarth Rules System
YSO	Young Stellar Object [Space]
YST	Yukon Standard Time
YT	Yukon Territory
YT	Yukon Time
YTD	Year To Date
YWCA	Young Womens Christian Association
YWHA	Young Womens Hebrew Association
Z	Zenith
Z	Zero
Z	Zulu (time)
ZB	Zero Beat
ZETA	Zero Energy Thermonuclear Assembly
ZGS	Zero Gradient Synchrotron
ZI	Zonal Index
ZIF	Zero Insertion Force (connector/socket)
ZIP	Zone Improvement Plan (US post office code)
ZK	barrage balloon (navy symbol)
ZMRI	Zinc Metals Research Institute
ZPG	Zero Population Growth
ZPRSN	Zurich Provisional Relative Sunspot Number
ZST	Zone Standard Time
ZT	Zone Time
ZWEI	Zwei Was Eine Initially

ANOTHER SUBMISSION from Steven F. Scharff

CAMP - Campaign Against Marijuana Prohibition
CREEP - Committee to Re-Elect the President (under Richard Nixon)
BOPEEP - Bognor-Orange Pasture Electronic Encounting Program (Electronic system to keep watch on =
WHIZ - What's His Is Zero (Ficticious feminist group)
NAMBLA - National Man-Boy Love Association (Pedophile group)
NAAWP - National Association for the Advancement of White People
WITCH - Womyn's International Terrorist Conspiracy from Hell (Feminist street theatre group)
RAEBNC - Read And Enjoyed, But No Comment (Fandom slang, pronounced "ray-bink")
MINAC - MINimum ACtivity (Fandom slang)
FORD {Humor} - Fast Overall Rapid Depreciation; F***ed Over Rebuilt Dodge
FIAT {Humor} - Fix It Again, Tony; Futile Italian Attempt at Transportation
VOLVO {Humor} - Very Odd Looking Vehicular Object
PONTIAC {Racist humor} - Poor Old N***** Thinks It's A Caddilac
BMW - Bavarian Motor Works; {Humor} Break My Window
DILLIGAF - Do I Look LIke I Give A F***? (Military slang)
TARFU - Things Are Really Fowled Up* (Military slang)
JANFU - Joint Army-Navy Fowl Up* (Military slang)
FUMTU - Fowled Up More Than Usual* (Military slang)
FUBB - Fowled Up Beyond Belief* (Military slang)
FUBAR - Fowled Up Beyond All Reason* (Military slang)
FUBAHAR - Fowled Up Beyond Any Hope Of Recovery* (Military slang)
BOHICA - Bend Over, Here It Comes Again (Military slang)
BOATILAM - Bend Over And Take It Like A Man
HC - Hard Core (Punk rock)
SE - Straight Edge (Punk rock [Drug-free, Sober])
SEUCK - Shoot 'Em Up Construction Kit (Computer game construction program)
ST:TNG - Star Trek: The Next Generation
ST:DSN (or ST:DS9) - Star Trek: Deep Space Nine
ST:V - Star Trek: Voyager
CE3K - Close Encounter of the Third Kind
TDD -Teletype Device for the Deaf
ASL - American Sign Language
BC - Boulder City (Nevada)
GOMER - Get Out of My Operating Room (Term used to describe someone who wanders into an O.R.
during surgery)
FLK - Funny Looking Kid (Offensive Medical slang for a Mongoloid child)
DEVO - Defective Equipment, Void Operation
BBROYGBVGW - Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gold, White (Capacitor code
colors for 0 to 9)
UNLV - University of Nevada, Las Vegas
UNR - University of Nevada, Reno
THC - Tetra Hydro Cannabinol  (Psychoactive compound in marijuana)
*More profane versions in use 
PS: "Gaia" is Latin.