Denizcilik Fakültesi

**Kaptan Sakin Türk** · #1 25 Kasım 2011

Acronym Definition 
------- ------------------------------------------------------- 
// Parallel transmission (simulcast) on -- 
/// Cloud layer below observing station 
+FC Tornado on the ground 
1 LT first lieutenant 
16-DPSK 16-Phase Differential Phase-Shift Keying 
16P4A 16 phase, 4 amplitudes 
2 LT second lieutenant 
220SMA 220 (MHz) Spectrum Management Assn (Amateur) 
2600 (1)2600 Hz, audio frequency used for US telephone idle tones 
2600 (2)Hack/Phreak magazine, named in honor of above 
2600 (3)Use of tone-spoofing equipment to control phone switches; now a good way to get caught phreaking and go to jail 
2G Second Generation 
2G ALE Second generation automatic link establishment 
32BDA 32-Bit Disk Access (Windoze) 
3D Three dimensional (like some weather models) 
3F Three-figure code groups (mixed or all numbers) 
3FG Three-figure code groups 
3G Third Generation 
3G ALE Third generation automatic link establishment 
3GPP Third Generation Partnership Project 
3G-TM Third Generation Traffic Management Protocol 
3L Three-letter code groups 
3LG Three-letter code groups 
4F Four figure code groups (mixed or all numbers) 
4FG Four figure code groups 
4G Fourth Generation 
4L Four-letter code groups 
4LG Four-letter code groups 
5 by 5 (1) Signal report: readability 5, strength 5 
5 by 5 (2) Signal report: you are loud and clear 
5D Demand Driven Direct Digital Dissemination 
5F Five-figure code groups (mixed or all numbers) 
5FG Five-figure code groups 
5L Five-letter code groups 
5LG Five-letter code groups 
73 Old telegraphy slang: "Best regards" 
81-81 Strange Russian teleprinting system, popular in Cuba 
88 Old telegraphy slang: "Love and kisses" 
89/336/EEC European electromagnetic compatibility directive 
8-DPSK 8-Phase Differential Phase-Shift Keying 
8P2A 8 phase, 2 amplitudes 
A Index 24-hour magnetic activity index, lower=better 
A (1)Altimeter setting 
A (2)Old "A" battery, for portable radio tube filaments 
A&P Airframe & Powerplant, U.S. aircraft mechanic certificate 
a/c Aircraft 
A/D Analog to digital converter 
A/G Air to ground 
A0 AM carrier with no modulation, now N0N 
A1 (Alpha-1) Aircraft maintenance status: no writeups; plane OK 
A1A Morse telegraphy for aural copy, i.e. "CW" 
A2 (Alpha-2) Status: write up non-mission-critical system 
A2A Modulated CW telegraphy for aural copy, i.e. "MCW" 
A3 (Alpha-3) Status: write up critical system; mission aborted 
A3E AM voice or broadcasting 
AA CW prosign: "[repeat] all after" 
AAA (1)Anti-Aircraft Artillery 
AAA (2)Authentication, Authorization and Accounting 
AAAS American Association for the Advancement of Science 
AAB Automatic Answer-Back (RTTY) 
AABCP Advanced airborne command post 
AAC Advanced Audio Coding 
AACC Airborne Air Command Center 
AADC Area Air Defense Commander 
AAF (1)Auxiliary Airfield 
AAF (2)Army Air Forces, obsolete 
AAFES Army and Air Force Exchange Service 
AAIC Accounting Authority Identification Code 
AAL ATM Adaptation Layer 
AAL-1 Synchronous adaptation layer designed for carrying voice trunk lines 
AAL-2 Adaptation layer intended for variable bit rate video, but never really got off the ground and is not offered by vendors 
AAL-3/4 Adaptation layer intended to be used by Frame Relay and SMDS and other delay-insensitive variable rate or bursty data traffic, but mostly now passed over in favour of AAL-5 
AAL-5 'Simple and efficient adaptation layer' for computer networking 
AALC (1)Amphibious Assault Landing Craft 
AALC (2)Amplified automatic level control 
AAM Air to Air Missile 
AAMDS Automated Air Movement Data System 
AAMSS Arinc Aeronautical Mobile Satellite Service (proposed; would replace much of MWARA) 
AAR (1)Air to Air Refueling 
AAR (2)After-Action Review 
AAR (3)Automatic Alternate Rerouting 
AAR (4)Assn. of American Railroads 
AARS Army Amateur Radio System, started 1925, now part of MARS 
AASS Advanced Air Surveillance Radar 
AATO Automated Air Tasking Order 
AAV Assault Amphibious Vehicle 
AAVP Advanced Aircrew Vision Protection 
AAW Anti-Air Warfare 
AB (1)Air Base 
AB (2)CW prosign: "[repeat] all before" 
ABA Australian Broadcasting Authority 
ABC (1)Atomic, Biological, Chemical (warfare) 
ABC (2)American Broadcasting Company 
ABC (3) Australian Broadcasting Corporation 
ABCA American, British, Canadian, Australian 
ABCC Airborne battlefield command and control center 
ABCCC Airborne Command Control Center 
ABCS Army Battle Command System 
ABD Air Base Defense 
ABIS Advanced Battlespace Information System 
ABITS Airborne Imagery Transmission System 
ABL Airborne Laser 
ABM Anti-Ballistic Missile 
ABN Airborne 
ABNCP Airborne National Command Post 
ABO Annular Beam Oscillator 
ABOR Abort 
ABU Asia Broadcast Union 
AC (1)Alternating Current 
AC (2)Active Components (US Army) 
AC (3)Acquisition Center 
AC&I Acquisition, Construction & Improvement 
ACA (1)Airspace control authority 
ACA (2)Australian Communications Authority 
ACAA Automatic chemical agent alarm 
ACAP Application Configuration Access Protocol (computing) 
ACAPS Area communications electronics capabilities 
ACARS Aircraft Communications Addressing and Reporting System 
ACAT Acquisition Category 
ACC (1)Air Combat Command (US) 
ACC (2)Area Communication Center 
ACC (3)altocumulus castellanus 
ACCHAN Allied Command Channel 
ACCINTNET ACC Intelligence Network 
ACCMSF Advanced Cooperative Collection Management 
ACCS Air Command and Control System 
ACE Airborne Command Element 
ACERT Army Computer Emergency Response Team 
ACF Autocorrelation Factor 
ACFT MSHP aircraft mishap 
ACI Air Control Intercept 
ACINT Acoustic intelligence 
ACIS Air Combat Information System 
ACJ Advisory Circular, Joint 
ACK Positive Acknowledgment (ASCII 06) 
ACLS Automatic Carrier Landing System 
ACM (1)Association for Computing Machinery 
ACM (2)Advanced Cruise Missile 
ACM (3)Air Combat Maneuvering 
ACMI Air Combat Maneuvering Instrumentation 
ACOM U.S. Atlantic Command 
ACP (01)Allied Communication Publication (127, etc) 
ACP (02)Allied Communication Protocol 
ACP (03)Adjacent Channel Power 
ACP (04)Adjacent Channel Protection 
ACP (05)Access Control Point 
ACP (06)Access Control Protocol 
ACP (07)Access Communications Processor 
ACP (08)Achieved Communication Performance (ARINC) 
ACP (09)Adaptive Communications Processor 
ACP (10)Advanced Communications Package 
ACP (11)Alternate Command Post 
ACP (12)Airborne Command Post 
ACP (13)Area Command Post 
ACP (14)Automated Command Post 
ACP (14)Applied Communication Program 
ACP (15)Automatic Communications Processor 
ACP (16)Automatic Colt Pistol 
ACP (17)Autoloading Colt Pistol 
ACP100 Allied Call Sign and Address Group System - Instructions and Assignments 
ACP110 Tactical Call Sign Book 
ACP112 Task Organization Call Sign Book 
ACP113 Call Sign Book for Ships 
ACP117 Allied Routing Indicator Book 
ACP119 Allied Tactical Voice Call Sign System - Instructions and Assignments 
ACP121 Communications Instructions - General 
ACP122 Communication Instructions - Security 
ACP123 Common Messaging Strategy and Procedures 
ACP124 Communication Instructions - Radiotelegraph Procedure 
ACP125 Communication Instructions - Radiotelephone Procedure 
ACP126 Communication Instructions - Radioteletype Procedure 
ACP127 Communication Instructions - Tape Relay Procedures 
ACP127SUP1A Allied RATT Procedures (RTTY) 
ACP128 ALTERS Operating Procedures 
ACP129 Communications Instructions - Visual Signalling Procedures 
ACP130 Direction Finding Procedure 
ACP131 Communication Instructions - Operating Signals 
ACP134 Telephone Switchboard Operating Procedure 
ACP135 Communications Instructions - Distress and Rescue Procedures 
ACP136 Communication Instructions - Panel Signaling 
ACP147 Call Sign Book for Merchant Ships in Time of War 
ACP148 Allied Guide to Master 
ACP149 Radio Communication Instructions for Merchant Ships Under Naval Control 
ACP150 Recognition and Identification Instructions, Air, Land, and Sea Forces 
ACP160 IFF SIF Operational Procedures 
ACP165 Operational Brevity Codes 
ACP167 Glossary of Communications-Electronics Terms 
ACP168 Pyrotechnic Signals 
ACP176 Allied Naval and Maritime Air Communication Instructions 
ACP177 Land Forces Electronic Warfare Instructions 
ACP178 Maritime Electronic Warfare Instructions 
ACP179 Electronic Warfare Instructions for Air Forces 
ACP190 Guide to Frequency Planning 
ACP198 Instructions for the Preparation of Allied Communications Publications 
ACR Armored cavalry regiment 
ACRM Automated Communication Resource Manager 
ACRONYM Actual Computer Related Overused Name You Mention 
ACS (1)Assistant chief of staff 
ACS (2)Agile Combat Support 
ACS (3)Airborne COMINT System 
ACS (4)Attitude Control System 
ACSB Amplitude Compandored SideBand 
ACSL altocumulus standing lenticular cloud 
ACT Airborne Communications Terminal 
ACTD Advanced Concept Technology Demonstration 
ACTEX Active Controls Technology Experiments 
ACTIVE Advanced Controls Technology for Integrated Vehicles 
ACTS (1)Air Combat Training System 
ACTS (2)Automated Computer Time Service 
ACU Avionics Control Unit 
ACW Air Control Wing (like 552nd AWACS at Tinker) 
ADA (1)Americans with Disabilities Act 
ADA (2)"Official" DoD computer language, not an acronym, named for Ada Babbage, the world's first programmer 
ADAS AWOS Data Acquisition System (Nice nested acronym) 
ADC Analog-to-Digital Convertor 
ADCC Air Defense Control Center 
addr Address 
ADDS Aviation Digital Data Service 
ADES Airdrop equipment and systems 
ADF (1)Automatic direction finding 
ADF (2)Australian Defence Forces 
ADIZ Air Defense Identification Zone 
ADM Admiral 
ADMD Administration Management Domain 
ADO (1)ActiveX Data Objects 
ADO (2)Active Data Objects 
ADOC Air defense operation center 
ADONIS Article Delivery Over Network Information Systems 
ADP Automated data processing 
ADPCM Adaptive differential pulse-code modulation 
ADPE Automated Data Processing Equipment 
ADPS ASARS Data Processing Station 
ADPSIS Automated Data Processing Software Inventory System 
ADPSO Automated Data Processing Security Officer 
ADPSSO Automated Data Processing System Security Officer 
ADR CW brevity: address 
ADRG ARC Raster Digitized Graphics 
ADS (1)Advanced Distributed Simulation 
ADS (2)Automatic Dependent Surveillance 
ADS-B Automated Dependent Surveillance-Broadcast 
ADSI Air Defense System Integrator 
ADSL Assymetric Digital Subscriber Line 
Ae Auroral Electrojet magnetic activity index 
AEEC Airlines Electronics Engineering Committee 
AEOS Advanced Electro-Optical System Spectrograph 
AEPDS Advance Electronic Processing and Dissemination System 
AES (1)Advanced Encryption Standard 
AES (2)Application Environment Specification 
AES (3)Audio Engineering Society 
AEW&C Airborne Early Warning & Control 
AF (1) Air Force 
AF (2) Audio Frequency (30 Hz - 30 kHz) 
AFAMPE Air Force Automated Message Processing Exchange 
AFATDS Advanced Field Artillery Tactical Data System 
AFB Air Force Base 
AFC Automatic frequency control 
AFCA Air Force Communications Agency (US) 
AFCS Automatic Flight Control System 
AFDC Air Force Doctrine Center 
AFEPS ACARS Front-End Processor System (ground computer network) 
AFETR Air Force Eastern Test Range 
AFEWES Air Force Electronic Warfare Effectiveness Simulator 
AFFF Aqueous Film Forming Foam (fire fighting) 
AFFSA Air Force Flight Standards Agency 
AFGIHS Air Force Geographic Information Handling System 
AFGWC Air Force Global Weather Central at Offutt AFB, NE 
AFI (1)Africa/Indian Ocean (MWARA) 
AFI (2)Air Force Instruction (official directive) 
AFI (3)American Film Institute 
AFIT Air Force Institute of Technology 
AFIWC AF Information Warfare Center 
AFK Absolute Frequency Keying (amateur very slow Piccolo) 
AFMC Air Force Materiel Command 
AFMSS Air Force Mission Support System 
AFN American Forces Network (US broadcast for military) 
AFNET Air Force Integrated Telecommunications Network 
AFOS Automation of Field Operations and Services 
AFOSR Air Force Office of Scientific Research 
AFR Armed Forces Radio 
AFRES Air Force Reserve (US) 
AFRL Air Force Research Laboratory 
AFRN Armed Forces Radio Network 
AFRTS Armed Forces Radio & Television Services 
AFS (1)Air Force Station 
AFS (2)Aeronautical Fixed Service 
AFSAA AF Studies and Analysis Agency 
AFSATCOM Armed Forces Satellite Communication 
AFSFC Air Force Space Forecasting Center 
AFSFCR AF Space Forecast Center Replacement 
AFSK Audio frequency-shift keying 
AFSOC Air Force Special Operations Command 
AFSOF Air Force Special Operations Forces 
AFTCO Air Force Telecommunications Certification Office 
AFTN Aeronautical Fixed Telecommunication Network 
AFV Alternate Fuel Vehicle 
AFW Air Force Weather 
AFWSS Air Force Weather Support System 
AFWTF Atlantic Fleet Weapons Training Facility 
AG (1)Adjutant general 
AG (2)Airlift Group 
AGC Automatic gain control 
AGE Aerospace Ground Equipment (pronounced like how old you are; when you replace it you order New Age) 
AGL (1)Above ground level 
AGL (2)Air to Ground Laser 
AGM Air to Ground Missile 
AGU American Geophysical Union 
AGWPE AGW Packet Engine (creator: SV2AGW) 
Ah Ampere-hour(s), battery capacity 
AH Authentication Header 
AHAMSL Antenna height above mean sea level 
AHD Acoustic Hailing Device 
AHDL Analog Hardware Descriptive Language 
AHF Adaptive High Frequency 
AHMSL Antenna height above mean sea level 
AHP Army Heliport 
AI (1)Artificial intelligence 
AI (2)Air Interdiction 
AI (3)Airborne Interceptor 
AI (4)Avionics Infrastructure 
AIA Air Intelligence Agency 
AIC Air Intercept Control 
AICPITS All India Coordinated Program of Ionosphere & Thermosphere Studies 
AIDA Atmospheric Investigations of Dynamics over Arecibo 
AIDC Automatic Identification and Data Capture 
AIFSS Automated International Flight Service Station 
AIG (1)Address Indicator Group 
AIG (2)Air Intelligence Group 
AIM (1)Air launched Interceptor Missile 
AIM (2)AOL Instant Messenger (popular internet talk program) 
AIN Advanced Intelligent Network (US NCS) 
AIR (1)All-India Radio 
AIR (2)Aviation Incident Response (Red Cross) 
AIREP Air Report; weather observation, like a PIREP 
AIRES Advanced Imagery Requirements and Exploitation System 
AIRK Area interswitch rekey 
AIRMET Air Meteorological Information 
AIRST Advanced Infrared Search and Track 
AIS (1)Automatic Identification System (USCG) 
AIS (2)(Universal) Automated Identification System 
AIS (3)Alarm Indication Signal 
AJ Anti-Jam 
AJCOM Anti-Jam Communications 
AkDT Alaskan Daylight Time, US 
AkST Alaskan Standard Time, US 
AL Approach and landing 
ALARM Air-Launched Anti-Radiation Missile 
ALC (1)Automatic level control 
ALC (2)Air logistics center 
ALC Air Logistics Center 
ALCC (1)Airborne Launch Control Center 
ALCC (2)Airlift Coordination Cell 
ALCE Airlift Control Element 
ALCF Airlift Control Flight 
ALCM Air Launched Cruise Missile 
ALCS (1)Airlift Control Squadron 
ALCS (2)Airborne Launch Control System 
ALE Automated Link Establishment 
ALERT Attack & Launch Early Reporting to Theater 
ALF Absorption Limiting Frequency, realtime version of LUF 
AlGaN Aluminum-Gallium Nitride 
ALOC Air lines of communication 
Aloha Wide-area net protocol, developed at U of Hawaii 
ALP airport location point 
lpha + # Aircraft maintenance status (1 is best) 
Alpha Hotel A-- H--- (also Adam Henry) 
ALQA Active Link Quality Analysis 
ALS (1)Advanced Life Support 
ALS (2)Airlift squadron 
ALTERS Allied Telecommunications Record System 
ALU Arithmetic Logic Unit (computer h/w) 
ALW Airlift Wing 
AM (1)Amplitude Modulation 
AM (2)Aeronautical Mobile 
AM (3)Ante Meridian, hours between midnight and 11:59 local 
AMARC Association Mondiale des Radiodiffusuers Communautaires 
AMASS Airport Movement Area Safety System 
AMBALG Algerian Embassy 
AMC (1)Air Mobility Command (old Air Force MAC, MATS) 
AMC (2)Army Materiel Command (US) 
AMCC Air Mobility Control Center 
AMCLD Active Matrix Liquid Crystal Display 
AMCO Aircraft maintenance company 
AMCS Air Mobility Control Squadron 
AMD (1)American Micro-Devices (with Cyrix, Intel's competition) 
AMD (2)Automatic Message Display 
AMDRFM Advanced Monolithic Digital Radio Frequency Memory 
AME (1)Automatic Message Exchange 
AME (2)Air Mobility Element 
AME (3)Amplitude modulation -----alent 
AMEDD Army Medical Department 
AMI Alternate Mark Inversion 
AMMCS Airborne Multimedia Multiservices Communication System 
AMO Air & Maritime Operations 
AMOG Air Mobility Operations Group 
AMOS Air Force Maui Optical Site 
AMP Antenna Maintenance Program 
AMPS (1)Advanced Mobile Phone Service (analog, obsolete) 
AMPS (2)Automated Mission Planning System 
AMRAAM Advanced Medium-Range Air-to-Air Missile 
AMRAD Amateur Radio Research And Development Corporation 
AMRS Austrian Military Radio Society 
AMS Analog Mixed Signal 
AMSA Australian Maritime Safety Agency 
AMSAT Radio Amateur Satellite, Inc. 
AMSI Arctic Maritime Safety Information 
AMTOR Amateur Teleprinting Over Radio (Ham SITOR) 
AMVER Automated Mutual Assistance Vessel Rescue System 
AMW Air Mobility Wing 
AMX Air Mobility Express 
AN Army/Navy (prefix on US military type designators) 
AN/FRT Army/Navy Fixed Radio Transmitting 
AN/GRC Army/Navy General Radio Communication 
AN/MRC Army/Navy Mobile Radio Communication 
ANARC Assn. of North American Radio Clubs 
ANDVT Advanced Narrowband Digital Voice Terminal 
ANG Air National Guard 
ANGB Air National Guard Base 
ANI Automatic Number Identification 
ANL Automatic noise limiter 
ANMCC Alternate National Military Communications Center (?)-WAR 46 
Annmt Announcement 
Annr Announcer 
ANS Advanced Network Services, operates an Internet backbone 
ANSI American National Standards Institution 
ANT (1)Antenna [~] 
ANT (2)Advantaged Node technology 
ANZUK Australia, New Zealand, United Kingdom (alliance) 
ANZUS Australia, New Zealand, United States (alliance) 
AO Area of operations 
AO1 automated station without precipitation discriminator 
AO2 automated station with precipitation discriminator 
AOA (1)Angle Of Arrival 
AOA ACARS Over AVLC (ARINC, neat nested acronym) 
AOC (1)Air Operations Center 
AOC (2)Army Operations Center (Pentagon) 
AOC (3)Air Operational Control 
AOE Airport of Entry 
AOI Area Of Interest 
AOO Area of operations 
AOR (1)Area of responsibility 
AOR (2)Atlantic Ocean Region (USCG GMDSS) 
AOV ACARS Over VDL (ARINC, neat nested acronym) 
AOS (1)Acquisition Of Signal 
AOS (2)Area Of Service 
Ap Planetary A index of geomagnetic activity 
AP Associated Press 
APC Armored personnel carrier 
APCO 25 New standard for digital public safety radio 
APCO Association of Public Safety Communications Officials 
API Application Programming Interface (computers) 
APIC APCO Project 25 Interface Committee 
APIPA Automatic Private Internet Protocol Addressing 
APL A Programming Language (computer code) 
APLink Amtor-Packet Link 
APNIC Asia Pacific Network Information Centre 
APO (1)Air Post Office 
APO (2)Army Post Office 
APOD Aerial port of debarkation 
APOE Aerial port of embarkation 
APPCON Approach Control 
APRNT apparent 
APRS (1)Automatic Position Reporting System, ham tracking w/GPS 
APRS (2)Automatic Packet Reporting System 
APRX approximately 
APSC APCO Project 25 Steering Committee 
APT Automatic Picture Transmissions 
APU Auxiliary Power Unit 
AQC Automatic Quick Call 
AR (1) Aerial refueling 
AR (2) Ground track for above 
AR (3) CW prosign: "End of message" 
AR (4) Army Regulation 
ARA Appletalk Remote Access, Mac networking 
ARB Air Reserve Base 
ARC (1)American Red Cross 
ARC (2)Airborne Radio Communications (AN/ARC-xxx) 
ARC (3)Air Reserve Component 
ARC-190 Common Collins mil HF aircraft radio, civil version is HF-190 
ARC-220 Fancy Collins HF radios for new US mil aircraft 
ARC-230 Collins 400-watt HF Link-11/Tadil-A aircraft radio, civil voice version is HF-121 
ARCAL Aircraft Radio Control of Aerodrome Lighting 
Archie Internet database search program, finds files 
ARCP Air Refueling Control Point 
ARD Automatic Ring Down 
ARDF (1)Automatic Radio Direction Finding 
ARDF (2)Amateur Radio Direction Finding 
AREC (1)Air resource element coordinator 
AREC (2)Amateur Radio Emergency Corps, now ARES 
ARES Amateur Radio Emergency Service 
ARF Air Reserve forces 
ARFA Allied Radio Frequency Agency 
ARFOR Army forces 
ARG (1)Amphibious Ready Group 
ARG (2)Air Refueling Group 
ARGOS Advanced Research and Global Observation Satellite 
ARIA Advanced Range Instrumentation Aircraft 
ARIB Association of Radio Industry Businesses (Japan) 
ARIDPCM Adaptive Recursive Interpolated Differential Pulse Code Modulation (whew!) 
ARIN American Registry for Internet Numbers 
ARINC Aeronautical Radio, Inc (US radio consortium) 
ARIP Air Refueling Initial Point 
ARISS Amateur Radio on the International Space Station 
ARM Anti-Radiation Missile 
ARMRV (1)Armored Mobile Reconnaissance Vehicle 
ARMRV (2)Armored Multi-Role Vehicle 
ARNG Army National Guard 
ARO Army Research Office 
ARP Address Resolution Protocol, Internet 
ARPA Advanced Research Projects Agency, operated original Internet 
ARPANET ARPA Network, became NSFNET, now separate from Internet 
ARQ Synchronous transmission and automatic repetition teleprinter system ("Acknowledge Request") 
ARQ6-90 Six-character blocks simplex ARQ teleprinter system 
ARQ-E3 Single channel ARQ teleprinter system 
ARRL American Radio Relay League 
ARRS Aerospace Rescue and Recovery Service 
ARS Amateur Radio Service 
ARSA (1)Airborne Reconnaissance and Surveillance Architecture 
ARSA (2)Airport Radar Service Area 
ARSOF Army special operations forces 
ARTCC Air Route Traffic Control Center 
ARTE (1)French media company 
ARTE (2)ADA Run Time Environment 
ARTG Amateur Radio Teleprinter Group (Swiss) 
ARTS Automated Remote Tracking Station 
ARW Air Refueling Wing (USAF/AFRES) 
ARWO Aerial Reconnaissance Weather 
AS (1) Air station 
AS (2) CW prosign: "Please Wait" 
AS (3) Analog secure (like original PARKHILL) 
AS (4)Submarine Tender (USN) 
ASA American Standards Association, obsolete 
ASAM Anti-Shipping Activity Message (warning) 
ASAP As Soon As [humanly] Possible; how one handles FLASH traffic 
ASAR Advanced Synthetic Aperture System 
ASARS Advanced Synthetic Aperture Radar System 
ASAS All Source Analysis System (US Army) 
ASAS-RWS ASAS Reconfigurable Work Station 
ASAT Antisatellite 
ASB Aviation support battalion 
ASC (1)AUTODIN Switching Center 
ASC (2)Accredited Standards Committee (ANSI) 
ASC (3)American Society of Cameramen (motion picture) 
ASC2A Air & Space Command & Control Agency 
ASCC Army service component command 
ASCIET All Services Combined Identification Evaluation Team 
ASCII American Standard Code for Information Interchange, 7-bit computer alphabet, usually extended to use 8th bit 
ASCOT Air Support Command Operations Task (RAF Air Transport) 
ASD Assistant Secretary of Defense 
ASDE-3 Airport Surface Detection Radar System 
ASDS Advanced SEAL Delivery System (a minisub; see SEAL) 
ASEAN Association of South East Asian Nations (old SEATO) 
ASECNA Agence pour la Securite de la Navigation Aerienne en Afrique et a Madagascar 
ASF Advanced Systems Format (Microsoft media player) 
ASG (1)Aeronautical Standards Groups 
ASG (2)Area support group 
ASIC Application Specific Integrated Circuit 
ASID Advanced Secure Information Dissemination 
ASIM Automated Security Incident Measurement 
ASIO Australian Security Intelligence Organisation 
ASIT Adaptable Surface Interface Terminal 
ASK Amplitude Shift Keying 
ASL Above Sea Level 
ASLAR Aircraft Surge Launch and Recovery 
ASM (1)Air to Surface Missile 
ASM (2)Analog Switching Module 
ASM (3)Assembler (computer code) 
ASMB Area support medical battalion 
ASMC Area support medical company 
ASME American Society for Mechanical Engineers 
ASMRO Armed Services Medical Regulating Office 
ASO Air surveillance officer 
ASOC Air Support Operations Center 
ASOS Automated Surface Observation System 
ASOTSE Army special operations theater support element 
ASP (1)Ammunition supply point 
ASP (2)Acquisition Support Plan 
ASP (3)Active Server Pages 
ASP (4)Application Service Provider 
ASR (1)Automatic Send-Receive 
ASR (2)Airport Suveillance Radar 
Assn Association 
Assoc Association 
AST Atlantic Standard Time, Canada 
ASTM American Society for Testing and Materials 
ASU Aircraft Starting Unit 
ASW Anti-submarine warfare 
AT (1)Advanced Technology (IBM's original name for its improved PC, now a standard architecture) 
AT (2)Amateur (radio allocation code) 
ATA (1)Army Technical Architecture 
ATA (2)AT Attachment 
ATA (3)American Trans Air 
ATAPI AT Attachment Packet Interface 
ATC Air Traffic Control 
ATCALS (1)Air Traffic Control and Landing System 
ATCALS (2)Air Traffic Control Liaison Section 
ATCCS Army Tactical Command & Control System 
ATCS Advanced Train Control System 
ATCT airport traffic control tower 
ATD Advanced Technology Demonstration 
ATDL 1 Army Tactical Data Link 1 
ATF Advanced Tactical Fighter 
ATF Bureau of Alcohol, Tobacco & Firearms 
ATH Air Transportable Hospital 
ATG Afloat Training Group (USN) 
ATHS Automatic Target Hand-off System 
ATIS Automated Terminal Information System (usually voice loop) 
ATM (1)Asynchronous Transfer Mode, 53-byte packets 
ATM (2)Automated Teller Machine 
ATM (3)Advanced trauma management 
ATMs Air Tasking Messages 
ATN Adventist Television Network 
ATO Air Tasking Order 
ATOI Aerial Track Of Interest 
A-TOR Automated Telex Over Radio 
ATP (1)Ammunition transfer point 
ATP (2)Appletalk Transaction Protocol, Mac networking 
ATP (3)Acquisition, Tracking & Pointing 
ATP (4)Authority to Proceed 
ATP (5)Air Traffic Procedures 
ATR Air Transport Rack (standard airplane radio bay) 
ATR/ATC Automatic Target Recognition/ Automatic Target Correlation 
ATS (1)Aeronautical Telecommunications Services 
ATS (2)Applications Technology Satellite 
ATSA Aviation and Transportation Security Act 
ATSC Advanced Television Systems Committee (US Digital TV) 
ATSC-H Handheld ATSC (for cell phones, also ATSC-M) 
ATU (1)Antenna Tuning Unit 
ATU (2)Arab Telecommunications Union 
ATU-A Arabic ATU-80 alphabet 
ATV (1)Amateur (fast-scan) television 
ATV (2)All-Terrain Vehicle 
AUI Attachment Unit Interface, Ethernet 
AUSREP Australian Ship Reporting System 
AUTO Weather observation is from automated station [~] 
AUTOCONET Automatic Digital Network Conference Network 
AUTODIN Automatic Digital Network (US military) 
AUTOVON Automatic voice network (now DSN as of 1990) 
AUV Autonomous Underwater Vehicle 
AUW All Up Weight (gross) 
AV Air Vehicle 
AVC Automatic volume control 
AVHRR Advanced Very High Resolution Radiometer 
AVI Audio Video Interleave (Microsoft file format) 
AVIM Aviation intermediate maintenance 
AVL Automatic Vehicle Locating 
AVLC (1)Aviation VHF Link Control 
AVLC (2)Automatic Vehicle Location and Control 
AVN AViatioN weather model 
AVO Air Vehicle Operator 
AVTR Airborne Video Tape Recorder 
AVUM Aviation unit maintenance 
AWACS Airborne Warning And Control System 
AWADS Adverse Weather Aerial Delivery System 
AWAPS Automated Weather Distribution System 
AWDS Adverse Weather and Debriefing System 
AWG American Wire Gauge 
AWGN Arbitrary White Gaussian Noise 
AWIPS Advanced Weather Interactive Processing System 
awk Aho, Weinstein & Kernighan, wrote a Unix script language 
AWN Aviation Weather Network, now on US Air Force Digital Weather Switch 
AWO American Waterway Operators 
AWOL Absent without leave 
AWOS Automated Weather Observing System 
AWR Adventist World Radio 
AWS (1)Air Weather Service 
AWS (2)Advisory Warning System 
AWS (3)Automated Weather Systems 
AWS (4)Automated Weather Station 
AWST Automated Weather Station 
AX.25 Amateur variant of CCITT X.25 packet radio protocol 
B (1)began 
B (2)old "B" battery for tube plates, typically 90 volts 
B&G Bombing & Gunnery 
B/m Benchmark 
B/U Backup 
B+ Tube plate voltage (highest in set) 
B8E Mode: Independent sideband, different voice programs 
B9W Mode: Independent sideband, mixed voice & data modes 
BA Braking action 
BAA (1)Broad Agency Announcement 
BAA (2)Broad Area Announcement 
BAC Broad Area Coverage 
BAe British Aerospace 
Bae British Aerospace 
BAI Backup Aircraft Inventory 
BAI Battle Area Interdiction 
Balun Balanced-to-unbalanced line transformer [~] 
BAM Beta and Advection Model (wx) 
BAN Base Area Networks 
BANANA Build Absolutely Nothing Anywhere Near Anyone (municipal response to most radio proposals) 
BAQ Basic allowance for quarters 
BAS Basic allowance for subsistence 
BASIC Beginners' All-Purpose Symbolic Instruction Code, computer language 
BAT (1)Blood Alcohol Testing (the "Batmobile," in the field) 
BAT (2)File extension: execute as command list (Batch job) 
BAT (3)Brilliant Anti-armor Submunition 
Baud Computer transmission unit, one state transition per second, no longer one bit per second in complex modulation schemes 
BBC British Broadcasting Corporation 
BBCS Broadband Connectivity Service (Swisscom) 
BBIS Battle Broadcast Information System 
BBN Backbone network 
BBS (1)Bulletin Board System (computer networking) 
BBS (2)Battery backup system 
BC (1)Broadcast 
BC (2)Back course 
BC (3)Patches (of sig. Weather) 
BC2A Bosnia Command & Control Augmentation 
BC3 Battle management and command, control and communications 
BCA Broadcast Control Authority 
BCB Broadcast Band (typically 540-1710 kHz) 
BCC (1)Base Communication Center 
BCC (2)Bureau Communication Center (LAPD) 
BCC (3)Battlefield circulation control 
BCC (4)Blind Carbon Copy (e-mail) 
BCD (1)Binary-coded decimal 
BCD (2)Bad conduct discharge 
BCE Base civil engineer 
BCF Backup communications facility, Dahlgren, VA 
BCFG Fog patches 
BCI (1)Broadcast interference (from xmtr to bc) 
BCI (2)Binary-coded information 
BCL (1)Broadcast listener 
BCL (2)Broadcast Communications Limited (New Zealand) 
BCM Baseline correlation matrix 
BCO (1)Base communications officer 
BCO (2)Base contracting officer 
BCO (3)Broad concept of operations 
BCP (1)Base communications package 
BCP (2)Base comprehensive plan 
BCS Broadcast Keying Station 
BCT Battlefield Communications Terminal 
bd Baud 
BDA (1)Battle damage assessment 
BDA (2)Bermuda (NASA) 
BDAR Battle damage assessment and repair 
bde Brigade 
BDU (1)HFDL: Basic Data Unit 
BDU (2)Battle dress uniform 
BEAR Beam Experiment Aboard Rocket 
BEC Bulk encrypted communications 
BEEF Base Engineering Emergency Force,("Prime BEEF team") 
BEL Bell (ASCII, RTTY) 
Bel Unit of voltage or power ratio, named for Alexander Graham Bell, usually expressed in deciBels 
BEP (1)Bit error probability 
BEP (2)break-even point 
BER Bit Error Rate 
BERT (1)Bit error rate test(er) 
BERT (2)Bit Error Rate Testing 
BF Basic Function 
BFACS Battlefield Functional Area Control Systems 
BFBS British Forces Broadcasting Service 
BFO (1)Beat frequency oscillator (CW/SSB mode of receiver) 
BFO (2)Backhaul follow-on 
BFSK Binary Frequency-Shift Keying 
BG Brigadier general 
BGEN Brigadier general 
BGP Border Gateway Protocol (TCP/IP) 
BICE Bureau of Immigration and Customs Enforcement 
BID Billing Identifier 
BIDDS Base integrated digital distribution system 
BIDS Backup information display system 
BIFC (1)Boise Interagency Fire Cache, obsolete 
BIFC (2)Boise Interagency Fire Center, now NIFC 
BiFET Bipolar Field Effect Transistor 
BIH Bureau International l'Heur, International Time Bureau, coordinates UTC leap seconds 
BILS Ballistic Impact Locator System 
Bin Binary 
BIND (1)Berkeley Internet Name Domain 
BIND (2)Berkeley Internet Name Daemon (old) 
BIND (3)Buggy Internet Name Daemon (geekspeak) 
Binhex Binary to hexadecimal, usually for sending binaries as ASCII 
BIOS Basic Input/Output System (part of computer op-system) 
BIOT British Indian Ocean Territory 
BIP Base Information Protect 
BIPS (1)Billion Instructions per Second (computing) 
BIPS (2)Backup Impact Prediction System 
BIPS Billion Instructions Per Second 
B-ISDN Broadband-Integrated Services Digital Network 
BIST Built-In-Self-Test 
Bit (1)BInary digiT, a one or zero, basic digital information unit 
BIT (2)Built-In Test 
BIT Built in Test 
Bit/s Bit per second 
BITE Built-In Test Equipment 
BITNET Because It's Time NETwork, from IBM, now global 
BIU Bus interface unit (computer h/w) 
BK CW prosign: long break or break-in 
BKN Broken cloud cover 
BL (1)Baseline 
BL (2)blowing 
BLAISE (1)British Library Automated Information Service 
BLAISE (2)Blaise Pascal, French Mathematician 
BLDU Blowing dust 
BLER Block Error Rate 
BLERT Block Error Rate Testing 
BLEVE Boiling Liquid Expanding Vapor Explosion 
BLM Bureau of Land Management (US) 
BLOS Beyond line of sight 
BLPY Spray 
BLS Bureau of Labor Statistics (US) 
BLSA Blowing sand 
BLSN Blowing snow 
BM Battle Management 
BMC2 Battle Management, Command and Control 
BMC3 Battle Management, Command, Control and Communication 
BMC3I Battle Management C3I 
BMC4ISR Battle Management C4I Surveillance and Reconnaissance 
BMD Ballistic Missile Defense 
BMDATC Ballistic missile defense advanced technology center 
BMDC Ballistic Missile Defense Center 
BMDCCC Ballistic missile defense command and control center 
BMDE Ballistic missile defense enhancement 
BMDO Ballistic missile defense organization, formerly SDIO 
BMDOC Ballistic missile defense operating center 
BMDSCOM Ballistic Missile Defense Systems Command, now U.S. Army Strategic Defense Command 
BMEWS Ballistic Missile Early Warning System 
BMO Ballistic Missile Office (US) 
BMOPS Battle Management Operations 
BMP (1)File extension: bitmap image 
BMP (2)Battle manager processor 
BMS Backward Music Station (weird RF feedback on HF) 
BMT (1)Ballistic Missile Threat 
BMT (2)Beam Management Terminal 
BMT (3)Bronx Motor Transit 
BMT (4)Ballistic Missile Technology 
BMT/SS Ballistic Missile transporter, storage and shipping 
bn Battalion 
BN CW prosign: repeat between -- and -- 
BNC (1)Bayonet Neill-Concelman (cable connector) 
BNC (2)Bayonet Navy Connector (alternate) 
BNC (3)Blimped Noiseless Camera (Classic Mitchell) 
BNCC Base Network Control Center 
BNCR Blimped Noiseless Camera, Reflex 
BnOC Battalion Operations Center 
BNSC British National Space Center 
BO Bad Order (inoperative unit writeup) 
BoD Board of Directors 
BOM Bureau Of Meteorology (Australia) 
BOND Beginning Of Next Day 
BOOTP Bootstrap Protocol 
BOOTP Bootstrap Protocol (IP addressing) 
BOPS Billion operations per second (computing) 
BOQ Bachelor Officer Quarters 
BORAM Block-Oriented RAM 
BOSS Battlefield Optical Surveillance System 
BOT Beginning of Tape 
bot Robot, typically a network program that does an admin duty 
BP Bandpass 
BPI Boost-Phase Intercept 
BPL Broadband over Power Line 
bpp bits per pixel 
bps Bit per second, not necessarily a "baud" 
Bps Bytes per second 
BPSK Biphase Shift Keying 
BQ (1)Beam Quality 
BQ (2)Acknowledging receipt (DSC protocol) 
BR Bridgewire resistance 
BR mist 
BRAC Base Realignment And Closure 
BRACC Base Realignment And Closure Commission (US military) 
BRB Be Right Back (Internet) 
BRD Broadcast 
brdg bridge 
BRI Basic Rate Interface 
BRI Basic Rate ISDN, 2 64Kbps channels 
BRV (1)Booster Recovery Vessel (NASA) 
BRV (2)Ballistic reentry vehicle (Stratcom) 
BS (1)Battle staff 
BS (2)Battle station 
BS (3)Backspace 
BS (4)aka "Bravo Sierra;" the excrement of bulls 
BSA (1)Brigade support area 
BSA (2)Birmingham Small Arms 
BSC Base security council 
BSD Berkeley Software Distribution (Unix type) 
BSE Broadcast Satellite Experiment 
BSKSA Broadcasting Service of the Kingdom of Saudi Arabia 
BSS (1)Broadcast Satellite System 
BSS (2)Broadcasting Satellite Service 
BSSC Battle staff support center 
BSTRS Base Support Trunked Radio System, aka "B-STARS" 
BSU (1)Baseband separation unit 
BSU (2)Bulk Storage Unit 
BSVS Backup Secure Voice System 
BT (1)("Bravo Tango") Bomb threat 
BT (2)CW prosign: short break 
BT (3)British Telecom 
BTC Block transfer controller (computing) 
BTH Below (beyond) the horizon 
BTI British Telecom International 
BTL Black telemetry (USAF) 
Btry Battery 
BTS Broadcast Transmitting Stations 
BTW By the way 
Buff Big Ugly Flying F[ellow] (B-52) 
BUFR Binary Universal Format for Representation 
BULLDOG BULLSEYE US Navy HF upgrade, like USAF's SCOPE, but includes DF [~] 
BUMCS Backup Master Control Station (GPS, Gaithersburg, MD) 
BUR Bottom Up Review 
BURN 1000W UHF aircraft orderwire (US mil; not an acronym, refers to high power) 
BVR Beyond Visual Range 
BVR Beyond visual range 
BW (1)Bandwidth 
BW (2)Biological Weapon 
BWC Bandwidth Compression 
BWS Base weather station 
BX Base exchange 
BZ ("Bravo Zulu") Good job 
C (1)Capacitance, in farads 
C (2)Confidential 
C (3)the C programming language 
C (4)Celsius 
C (5)Designator for head of British MI6 
C (6)Center (with reference to runway designation) 
c The speed of light, and radio waves, in a vacuum 
C&DH Communications & Data Handling 
C&DP Communications & Data Processing 
c/s Callsign 
c/w Callword 
C2 Command and Control 
C2CM Command and Control Countermeasures 
C2IPS Air Mobility Command and Control Information Processing System 
C2P Command and Control Processor 
C2V Command and Control Vehicle 
C2W Command and Control Warfare 
C2WC Command and Control Warfare Commander (US Navy) 
C3 Command, Control and Communications 
C3F Mode designation: television or video 
C3I Command, Control, Communications and Intelligence 
C3S Command, control and communications segment 
C3SMP Command, control and communications system master plan 
C4I Command, Control, Communications, Computers and Intelligence 
C4ID Command, Control, Communications, Computers and intelligence Dissemination 
C4IFTW C4I for the Warrior 
C4ISR Command, Control, Communications, Computing, Intelligence, Surveillance, & Reconaissance 
C4S Command, Control, Communications, Computer Systems 
C4SMP Command, control, communications and computers system master plan 
CA (1)civil affairs 
CA (2)COMSEC Account 
CA (3)cloud-air lightning 
CA (4)Counter Air 
CA (5)Cyanoacrylate (Super Glue) 
CAATS Canadian Automated Air Traffic System 
CAB Combat Area Broadcast 
CACS Command And Control Squadron 
CAD (1)Computer-aided design 
CAD (2)Coherent amplitude detector 
CAD (3)Computer-aided dispatch 
CAD/CAM Computer aided design/computer aided manufacturing 
CADRG Compressed Arc Digitized Raster Graphics 
CAE (1)Common Application Environment 
CAE (2)Computer Aided Engineering 
CAEWIS Computer Aided Electronic Warfare Information System 
CAF Combat Air Forces 
CAFWSP CAF Weather Support Package 
CAI (1)Computer-aided instruction 
CAI (2)Cooperative Airborne Identification 
CAINS Carrier Aircraft Inertial Navigation System 
CAL Calibrate, calibration 
CALLS Contact And Long-range Liaison System (USCG) 
CALM Codan Automated Link Management 
CALS (1)Computer-aided Acquisition & Logistics System 
CALS (2)Contingency Airfield Lighting System 
CAM Computer-aided manufacturing 
camo Camouflage 
CAMO Computer-aided manual operation 
CAMSLANT Communications Area Master Station, Atlantic 
CAMSPAC Communications Area Master Station, Pacific 
CAN (1)Cancel (ASCII) 
CAN (2)Controller Area Network (industrial automation) 
CANFORCE Canadian Forces 
CANR Canadian NORAD Region 
CANUS Canada/US 
CAOC (1)Combined Air Operations Center 
CAOC (2)Combined Allied Operations Center, Vicenza, IT (Allied Force) 
CAP (1) Civil Air Patrol 
CAP (2) Carrierless Amplitude Phase 
CAPCOM Capsule Communicator (NASA) 
CAPEG Cape Canaveral Ground Antenna (GPS) 
CAPPS Computer Assisted Passenger Prescreening System 
CAPS Center for the Analysis and Prediction of Storms (NWS) 
CAPT Captain 
CAR Caribbean (MWARA) 
CARB Channel Availability Radio Bulletin (NATO) 
CARCAH Chief, Aerial Reconnaissance Coordination, All Hurricanes (NHC) 
CARIBROC Caribbean Regional Operations Center 
CARR Corrective Action Request & Report 
CAS (1)Close Air Support 
CAS (2)Collision Avoidance System 
CAS (3)Calibrated Air Speed 
CASE (1)Common automated system execution 
CASE (2)Computer-aided software engineering 
CASE (3)Computer-aided system engineering 
CASREP Casualty Report 
CAT (1)Clear Air Turbulence 
CAT (2)Computer Aided Transceiver, proprietary control interface 
CATIS Computer Aided Tactical Information System 
CATT Computer Assisted Technology Transfer 
CATV Community Antenna Television ("cable") 
CAU Crypto Ancillary Unit 
CAV (1)Collision Avoidance 
CAV (2)Conditionally Available (LA City FD) 
CAV (3)Ceiling and visibility 
CAVOK Ceiling & Visibility OK (non-US METAR) 
CAVU Ceiling & visibility unlimited 
CB (1)Citizen Band Radio (legal or otherwise, around 27 MHz) 
CB (2)Cumulonimbus (thundercloud) 
CBAA Community Broadcasting Association of Australia 
C-band 4-8 GHz microwave band 
CBC Canadian Broadcasting Company 
CBFS Cesium Beam Frequency Standard 
CBM Central battle management 
CBMAM Cumulonimbus mammatus cloud 
CBP Customs and Border Protection 
CBR (1)Chemical, Biological, Radiological (warfare) 
CBR (2)Constant bit rate 
CBRN Caribbean Basin Radar Network 
CBS Columbia Broadcasting System (U.S.) 
CBT (1)Computer-based training 
CBT (2)Combat 
CBTS Computer-based training system 
CBU Cluster Bomb Unit 
CBW (1)Chemical & Biological (warfare) 
CBW (2)Constant bandwidth 
CC (1)Transmission is in Standard Chinese ("Mandarin") 
CC (2)Command & Control 
CC (3)Command Center 
CC (4)Control Center 
CC (5)Commander 
CC (6)Computer controller 
CC (7)Copies 
CC (8)C Compiler (unix) 
CC (9)cloud-cloud lightning 
CC&D Camouflage, concealment and deception 
CC&R Covenants, Conditions & Restrictions; what you check before buying a home if you intend to build an antenna there 
CCAS Cape Canaveral Air Station, FL, formerly CCAFS 
CCB (1)Configuration Control Board 
CCB (2)Computer Controlled Brake (railroad) 
CCC (1)Central computer complex 
CCC (2)Communications control complex 
CCC (3)Consolidated Command Center (NORAD) 
CCD Charge Coupled Device 
CCDM Consultative Committee for the Definition of the Meter 
CCDS Consultative Committee for the Definition of the Second 
CCE (1)Command & control element 
CCE (2)Consultative Committee on Electricity 
CCEMRI Consultative Committee for Ionizing Radiations 
CCG Calibration Coordination Group 
CCIP Continuously-Computed Impact Point 
CCIR International Radio Consultative Committee, now ITU-R 
CCIR 476-4 International SITOR character set 
CCIRID Charge-coupled infrared imaging device 
CCITT Comite Consultatif International de Telegraphique et Telephonique (International Telegraph & Telephone Consultative Committee), obsolescent 
CCL Common Command Language 
CCM (1)Combined Cipher Machine (WWII Allies) 
CCM (2)Counter-Countermeasures 
CCMC Canadian Centre for Maritime Communications 
CCP Console Command Processor, part of CP/M 
CCPC Civil Communications Planning Committee (NATO) 
CCPDS-R Command Center Processing and Display System - Replacement 
CCR Central Control Room 
CCRP Continuously-Computed Release Point 
CCS (1)Continuous Commercial Service (power rating) 
CCS (2)Charge Control System 
CCSL cirrocumulus standing lenticular cloud 
CCT Computer Compatible Tape 
ccTLD Country Code Top Level Domain 
CCTV Closed Circuit Television 
C-cubed Command Control and Communications 
CCV Code change verifier 
CCW (1)Counter-clockwise 
CCW (2)Command & Control Warfare 
CCW (3)Continuous Carrier Wave 
CCW (4)Coherent CW 
CCW (5)Class C CW biasing (most efficient) 
CD (1)Compact Disc 
CD (2)Civil Defense (in U.S., now FEMA) 
CD (3)Carrier detect (modem line) 
CDA (1)Central distribution amplifier 
CDA (2)Command & data acquisition 
CDB Command data buffer 
CDC (1)Canadian Department of Communications 
CDC (2)Centers for Disease Control (US) 
CDC (3)Control Data Corporation 
CD-DA Compact Disc Digital Audio (format, part of the "Red Book") 
CDE Common Desktop Environment 
CDF (1)Common Data Format 
CDF (2)California Division of Forestry (fire fighters) 
CDHF Central Data Handling Facility 
CD-I Compact Disc - Interactive (one format in the "Green Book") 
CDIS Canadian Defence Intelligence Staff 
CDL Common Data Link 
CDM Chemical Downwind Message (US Army) 
CDMA Code Division Multiple Access 
CDMA One (IS-95) Qualcomm 2nd generation CDMA 
CDMA2000 3G CDMA technology 
CDNU Control Display Navigation Unit 
CDPD Cellular Digital Packet Data 
CDR (1)Commander 
CDR (2)Command destruct receiver (Stratcom) 
CD-R Compact Disc - Recordable 
CDRAM Cache Dynamic Random Access Memory 
CD-ROM XA CD-ROM eXtended Architecture, extends the "Yellow Book" 
CD-ROM Compact Disc Read Only Memory 
CD-RTOS Compact Disc - Real Time Operating System (CD-I) 
CDS (1)Canadian Defence Staff 
CDS (2)Combat Direction System 
CDT Central (US) Daylight Time 
CDU Control display unit (fancy "control head") 
CE (1)Conformite Europeanne (European Conformity); mark put on products for EEC 
CE (2)Committee that sets these requirements 
CEC (1)Commission of the European Communities (drafts "CE" standards) 
CEC (2)Cooperative Engagement Capability 
CECOM US Army Communications Electronics Command 
CENTCOM U.S. Central Command 
CEOI Communications-Electronics Operation Instructions 
CEP (1)Central East Pacific (MWARA) 
CEP (2)Circular Error Probability 
CEP (3)Circular Error Probable 
CEPPO Chemical Emergency Preparedness and Prevention Office 
CEPT Conference of Postal & Telecommunications Administrations (EU) 
CEPTAG Civil Emergency Planning Telecommunications Advisory Group (Joint US/Canadian) 
CERDEC Communications Electronics Research, Development and Engineering Center 
CERN Centre Europ'eene por la Recherche Nucleaire, Center for European Nuclear Research, huge particle accelerator center, WWW originated there 
CERT Computer Emergency Response Team (Internet security) 
CF (1)Canadian forces 
CF (2)Center frequency 
CFAP Commandement Force Aerienne de Projection (French AF) 
CFARS Canadian Forces Affiliate Radio System 
CFB Canadian Forces Base 
CFBL Call Forwarding Busing Line (telco) 
CFBS Canadian Forces Broadcasting Service 
CFDA Call Forwarding Don't Answer (telco) 
CFEP Communications front end processor 
CFL Confidential Frequency List (good shortwave publication) 
CFM Cubic feet per minute 
CFR 33: USCG Navigation Regulations 
CFR 46: USCG Vessel Regulations 
CFR 47: FCC Regulations 
CFR Code of Federal Regulations 
CFS (1)Center for Standards 
CFS (2)Canadian Forces Station 
CFT Center Frequency Tone 
CG (1)Coast Guard 
CG (2)Commanding General 
CG cloud-ground lightning 
CGAS Coast Guard Air Station 
CG-C2 Coast Guard Command & Control 
CGCWOA (US) Coast Guard CW Operators Assn. (see CW) 
CGDN Coast Guard Data Net 
CGM (1)Computer Graphics Metafile 
CGM (2)Corrected Geomagnetic coordinates 
CGMS Coordinating Group for Meteorological Satellites 
CGSIC Civil GPS Service Interface Committee 
CGU Canadian Geophysical Union 
Ch mkr Channel marker 
Ch Channel 
CHAP Challenge Handshake Authentication Protocol (PPP) 
CHATH Chemically/Biologically Hardened Air Transportable Hospital 
CHBDL Common High Bandwidth Data Link 
CHBDL-ST Common High Bandwidth Data Link-Surface Terminal 
C-HFET Complementary Heterostructure Field Effect Transistor 
CHI cloud-height indicator 
CHINO sky condition at secondary location not available 
CHOP (1)Change in Operational Control 
CHOP (2)Chief Operator (Navy MARS) 
CHOP (3)Counter Measures Hands-on Program 
CHS Combat health support 
CHS Cylinder, Head, Sector (direct disk addressing) 
CIA Central Intelligence Agency (US) 
CIBAR Conference of International Broadcasters' Audience Research Services 
CIC (1) Combat Information Center (Navy) 
CIC (2) Combined Intelligence Center (US Air Force) 
CIC (3)Combined Intelligence Center 
CICA Competition in Contracting Act 
CICBMs Conventionally-armed ICBMs 
CICS Customer Information Control System (IBM) 
CID (1)Circuit Identifier 
CID (2)Combat Identification 
CIDE Communication Information Data Exchange 
CIDR Classless Inter-Domain Routing (Internet, replaces class A-C) 
CIDX Canadian International DX Club 
CIG ceiling 
CIIP Common Imagery Interoperability Profiles 
CIJ Close In Jamming 
CIL Command Image Library 
CINC Commander In Chief, replaced by CDR 2003 
CINCLANT C in C, Atlantic, obsolete 
CINCNORAD C in C, NORAD, obsolete 
CINCPAC C in C, Pacific, obsolete 
CINCSTRAT C in C, Stratcom, obsolete 
CIOL Common Interface Objects Language 
CIPO Commanders in chief Interoperability Program Office 
CIPSO Common Internet Protocol Security Options 
CIRC Cross Interleaved Reed Solomon Code 
CIRAF French acronym for international broadcast zone system 
CIRF Co-Channel Interference Reduction Factor 
CIS (1)Combat Intelligence System 
CIS (2)Commonwealth of Independent States (replaced USSR) 
CISC Complex Instruction Set Computing 
CISCO Consolidated intelligence support to combat operations 
CISPR International Special Committee on Radio Interference 
CIT California Institute of Technology (CalTech) 
CITS Combat Information Transfer System 
CI-V Radio computer interface made by Icom 
CIW Combined Intelligence Watch 
CIWS Close-In Weapons System 
CJCS Chairman, Joint Chiefs of Staff (US) 
CJCSI Chairman of the Joint Chiefs of Staff Instruction 
CJCSM Chairman of the Joint Chiefs of Staff Memo 
CJFET Complementary junction field effect transistor 
CJMAO Central Joint Mortuary Affairs Office 
CK Check (usually word count in a message) 
CL (1)Centerline Lighting System 
CL (2)CW prosign: I am closing my station (clearing) 
Class A (1)Stage is biased to conduct continuously 
Class A (2)High explosive (military phone patches) 
Class B Stage is biased to conduct on half of cycle 
Class C (1)Stage is biased to conduct less than half 
Class C (2)Gunpowder (military phone patches) 
Class D Digital switching 
Class E New, like D 
CLC Circuit Link Control 
Clg Calling 
CLIPER CLImatology and PERsistence (weather model) 
CLOVER Robust RTTY mode for HF 
CLR (1)Clear 
CLR (2)Clear below 12,000 feet (automated METAR) 
CLR (3)Common Language Runtime (MickeySoft) 
CM (1)Countermeasures 
CM (2)Cipher Machine 
CM (3)Corrected Geomagnetic coordinates 
CM (4)Chemical Mace, a tear gas 
CM (5)Configuration Management 
cm (1)Centimeter 
cm (2)Control monitor 
CMARS Cruise Missile Autonomous Routing System 
CMAS Cheyenne Mountain Air Station, was CMAFB, CMAFS 
CMAWS Common Missile Approach Warning System 
CMC (1)Cheyenne Mountain Complex (NORAD) 
CMC (2)Command management center 
CMC (3)COMSAT Mobile Corporation, part of COMSAT 
CMCS COMINT Mission Collection System 
CMD (1)Command 
CMD (2)Network Command (ALE) 
CMDR Commander 
CMDS Countermeasure Dispenser Set 
CME Coronal Mass Ejection, causes aurora 
CMF Combat Mission Folder 
CMI Computer-managed instruction 
CMIS (1)Cheyenne Mountain Interface Subsystem 
CMIS (2)Closed Loop Maintenance Information System 
CMLSA Commercial Microwave Landing System Avionics 
CMMB China Multimedia Mobile Broadcasting 
CMO (1)Central Measurement and Signature Intelligence (MASINT) Office 
CMO (2)Civil-military operations 
CMOC Cheyenne Mountain Operations Center 
CMOS (1)Complementary Metallic Oxide Semiconductor 
CMOS (2)Cargo Movement Operations System 
CMP Common Management Practices 
CMR Crisis Management Reconnaissance 
CMRS Commercial Mobile Radio Service 
CMS (1)Canadian Maritime Service 
CMS (2)Calendar Messaging Service (Solaris) 
CMS (3)Common Mapping System 
CMS (4)Community Management Staff 
CMS (5)Counter Measures Set 
CMS (6)Counter Measures System 
CMSA Cruise Missile Support Activity 
CMT Cellular Mobile Telephone 
CMU Cheyenne Mountain Upgrade 
CMX Crisis Management Exercise (NATO) 
CMY Cyan, Magenta, Yellow (subtractive color printing) 
CMYK Cyan, Magenta, Yellow, blacK (4-color printing) 
CN (1)Communications network 
CN (2)Counter-narcotics 
CNA Center for Naval Analysis 
CNAAS Counter-narcotics air analysis system 
CNCE Communications nodal control element 
CNCS Centralized Net Control Station (Scope Command hub at Andrews AFB) 
CNE (1)Communications Network Environment 
CNE (2)Communications Node Emulator 
CNE (3)Certified Netware Engineer (Novell) 
CNES Centre National d'Etudes Spatiales (French space agency) 
CNI Communications, Navigation, and ID 
CNM (1)Communications Network management 
CNMI Commonwealth of the Northern Mariana Islands 
CNN Cable News Network 
CNO (1)Chief of Naval Operations 
CNO (2)Casualty notification officer 
CNR Combat Net Radio 
CNRADL Canadian RADIL (ROCC/AWACS digital information link) 
CNS (1)Communications, navigation & surveillance 
CNS (2)Central nervous system 
CNS (3)Consolidated NOTAM System (Another nested acronym courtesy FAA) 
CNTRA Chief of Naval Air Training (pronounced "Sinatra" like the singer) 
CO (1)Commanding Officer 
CO (2)Central Office (telcom) 
CO (3)Contracting Officer 
co UK version of .com (Internet domain) 
CO/MIS Commander, Management Information Center 
COA Courses of Action 
Coax Coaxial cable 
COBOL Common Business Oriented Language (clunky old programming code) 
COBRA DANE US military air surveillance radar system 
COBRA (1)Coastal Battlefield Reconnaissance System 
COBRA (2)Counter Battery Radar 
COBRA (3)Coaxial Beam Rotating Antenna 
COCOM Combatant command 
COD (1)Carrier Onboard Delivery 
COD (2)Collect On Delivery 
CODAR Coastal Ocean Dynamics Radar 
CoDE Coherent Digital Exciter 
Codec Coder/Decoder 
COE (1)Circle of Error 
COE (2)Common Operating Environment 
COE (3)Central Office Equipment 
COFAS Commandement Force Aerienne Strategique (French AF) 
COFC Container On Flat Car (as opposed to container car) 
COFF Common Object File Format (Windoze) 
CofS Chief of Staff 
COG Continuity Of Government (emergency plan) 
COI Critical Operational Issue 
COIL Chemical Oxygen-Iodine Laser 
COL Colonel 
COM (1)Computer file extension: load as simple command program 
COM (2)Commercial domain (Internet) 
COM (3)Component Object Module (Windoze) 
COMACC Commander, Air Combat Command 
COMAFFOR Commander Air Force Forces 
COMAFSPACE Commander, Air Force Space Command 
COMARSPACE Commander, U.S. Army Space Command 
COMASWFORLANT Commander, ASW Forces Atlantic 
COMCON Communications Condition (MARS) 
COMFAIRMED Commander, Fleet Air Mediterranean 
COMFAIRWINGTEN Commander, Fleet Airwing Ten 
COMHSWINGONE Commander, Helicopter Antisubmarine Wing One 
COMINT Communications Intelligence 
COMJAM Communications jamming 
COMM Communications 
Comm Communications (also "commo") 
COMMSTA Communication Station 
COMMZ Communications zone 
COMNAVCOMTELCOM Commander, Naval Computer and Telecommunications Command 
COMOPTEVFOR Commander, Operational Test and Evaluation Force 
COMPATWING Commander, Patrol Wing 
COMPATWINGSLANT Commander, Patrol Wings Atlantic 
COMPUINT Computer intelligence 
Compul Compulsory 
COMPUSEC Computer Security 
COMSAT (1)COMmunication SATellite 
COMSAT (2)Comsat Corp., US consortium & INMARSAT Convention rep 
COMSEABASED Commander, Sea-Based ASW Wings, Atlantic 
COMSEC Communication Security 
COMSTAT Communications Status Report 
COMSUBLANT Commander, Submarine Forces, Atlantic (USN) 
COMSUBPAC Commander, Submarine Forces, Pacific (USN) 
COMTAC Communications Tactical 
CONCISE Cosine Network's Central Information Service for Europe 
CONDX CW brevity: propagation conditions (usually wretched) 
CONELRAD Control of Electromagnetic Radiation, obsolete 
Config Configuration, configure 
conmara Italian Consulate, Maracaibo, Venezuela 
conmars Italian Consulate, Marseille, France 
conmopr Italian Consulate, possibly Montpellier, France 
conmpla Italian Consulate, Mar del Plata, Argentina 
CONOP(s) Concept of Operations(s) 
CONS continuous 
conspie Italian Consulate, possibly St. Pierre 
contolo Italian Consulate, Toulouse, France 
CONUS continental United States 
conwett Italian Consulate, Wettingen, Switzerland 
COOP Continuity Of Operations (US Army) 
Coq Coquelet (French teleprinting system, after "Rooster") 
Coq8 8-bit Coquelet 
COR (1)Carrier operated relay 
COR (2)Consolidated Operations Room ("Lights Out") 
COR (3)Correction to a previously disseminated weather report 
CORES Commission Registration System (FCC) 
COS Communication Operations Segment 
COSCOM Corps support command 
COSE Common Open Software Environment 
COSIP Computer Open System Interface Processor 
COSPAS Acronym for Russian SARSAT 
COT Changeover time 
COTHEN Customs Over The Horizon Enforcement Network (US) 
COTS Commercial Off-The-Shelf 
COWS Cells On Wheels (post-disaster cellphone service) 
CP (1)Command Post 
CP (2)CW general call: "Hello -- [2 or more callsigns follow]" 
CP (3)Contental Polar (air mass) 
CP/M Early Z80 operating system, might or might not have stood for "Control Program for Microcomputers," or "Control Program/Monitor." The guy who would know is dead, having narrowly missed out on being richer than Bill Gates. 
CPA (1)Closest Point of Approach 
CPA (2)Certified Public Accountant 
CPAS Cellular Priority Access Service 
CPCA Camp Parks Communications Annex (USAF) 
CPDLC Controller-Pilot Data Link Communications 
CPE Customer Premise Equipment (telco) 
CPFSK Continuous-Phase Frequency Shift Keying 
CPM Continuous Phase Modulation 
CPO Chief Petty Officer 
CPR Cardio-pulmonary resuscitation 
CPS (1)Characters Per Second 
CPS (2)Cellular Priority Services (US NCS) 
cps Cycle per second (one Hertz) 
CPT Captain (US Army) 
CPU Central Processing Unit (computer h/w) 
CPX Command Post Exercise (NATO) 
CQ General call: "Hello all stations" 
CQD "Hello All Stations, Distress," no longer used 
CQWW CQ World Wide (Amateur DX contest) 
CR Carriage Return 
CRAF Civil Reserve Air Fleet 
CRATT Crypto Radio Teletype (usually military & encrypted) 
CRC (1)Cyclic Redundancy Check (computer error test) 
CRC (2)CONUS Replacement Center 
CRC (3)Control & Reporting Center 
CRE Control & Reporting Element 
CREN Corporation for Research and Educational Networking 
CRIS Communications Resource Information Sharing (US NCS) 
CRM Computer Resource Management 
CRO (1)Cathode-Ray Oscilloscope 
CRO (2)Croatia (country code) 
CRO (3)Coaxial Resonator Oscillator 
CROSS Centres Regionaux Opérationnels de Surveillance et de Sauvetage (French RCC, see RCC) 
CRPLF French language: Francophonic Public Radio Community 
CRR Carrier 
CRRL Canadian Radio Relay League 
CRS Coastal Radio Station 
CRT Cathode-Ray Tube (usually a computer terminal) 
CRTC Combat Readiness Training Center 
CS (1)combat support 
CS (2)communication squadron 
CS (3)Chicken S-it 
CS (4)Chemical Shield (a tear gas) 
CSAF Air Force Chief of Staff 
CSAR Combat Search and Rescue 
CSARP Common SAR Processor 
CSB Corps support battalion 
CSC (1)Combat Support Center (AFOC) 
CSC (2)Combat stress control 
CSC (3)Computer Software Component 
CSCI Computer Software Configuration Item 
CSE Client/Server Environment 
CSEL Combat Survivor Evader Locator (pilot survival radio) 
CSG (1)Carrier Strike Group 
CSG (2)Corps support group 
CSH Combat support hospital 
csh C-shell, popular Unix command interpreter 
CSMA/CD Carrier Sense Multiple Access/ Collision Detection 
CSOM Computer Software Operators Manual 
CSP Communications Support Processor 
C-SPAN Cable-Satellite Public Affairs Network (US) 
CSS (1)Combat service support 
CSS (2)Central Security Service (US SIGINT, run by NSA director) 
CSS (3)Cascading Style Sheets 
CSS (4)Content Scrambling System (DVD encryption) 
CSSCS Combat Service Support Control System 
CST (1)Central (US) Standard Time 
CST (2)Caribbean Support Tender 
CST (3)Civil Support Team 
CSTARS COMBAT SENT Technical Acquisition Receiver System 
CSU Computer Software Unit 
CT (1)Center Tap 
CT (2)("Charlie Tango") - Communications Technician (on an aircraft) 
CTA Control Area 
CTAF Common Traffic Advisory Frequency 
CTAPS Contingency Tactical Air Combat System 
CTBT Comprehensive Test Ban Treaty 
CTC (1)Centralized Traffic Control (railroad) 
CTC (2)Counter-Terrorism Command 
CTCSS Continuous Tone Coded Squelch System ("PL") 
CTI Computer - Telephone Integration 
CTIA Cellular Telecommunications Industry Assn 
CTLZ Control Zone 
CTP Critical Technical Parameter 
CTR Combat Training Range 
Ctrl (1)Control 
Ctrl (2)Computer's control key, sometimes shown with a ^ 
CTS Clear To Send (Serial I/O handshaking line) 
CTT Commander's Tactical Terminal 
CU CW brevity code: "See you" 
CUAGN CW brevity code: "See you again" 
CUBIC Common User Baseline for the Intel Community 
CUCV commercial utility cargo vehicle 
CUL CW brevity code: "See you later" 
CV (1)USN Aircraft Carrier 
CV (2)Vice Commander 
CVBG Carrier Battle Group 
CVIC Carrier Intelligence Center 
CVN US nuclear aircraft carrier 
CW (1)Continuous Wave (usually Morse code) 
CW (2)Clockwise (rotation) 
CW (3)Composite Wing 
CWDE Chemical Warfare Defense Ensemble 
CWIS Campus-Wide Information System 
CWISP Campus-Wide Information System Protocol 
CWOC Composite Wing Operations Center 
CWP Central West Pacific (MWARA) 
CWS Combat Weather System 
Cygnus Cygnus, Your Gnu Support (nested recursion; see Gnu) 
CZ (Panama) Canal Zone 
D (1)Down 
D (2)Diode 
D/A Digital/Analog converter 
D/L (1)Downlink 
D/L (2)Download 
D2 Degrade and Destroy 
D2C D-2 Small Cassette 
D3 Degrade Disrupt Deny 
D4 (1)Degrade Disrupt Deny Destroy 
D4 (2)Deny, Disrupt, Degrade, & Destroy 
D4EN Disrupt, Delay, Destroy, Exploit, or Neutralize 
DA (1)Directional antenna 
DA (2)Department of the Army 
DA-2 Station changes directional pattern at night (FCC) 
DAB Digital Audio Broadcasting 
DAB+ Newer DAB standards, not backward compatible 
DAC (1)Digital-to-Analog Converter 
DAC (2)Disaster Assistance Center (FEMA) 
DAC (3)Disaster Application Center 
DACT Data Automated Control Terminal 
DAE Disaster Assistance Employee 
DAGS Data Architecture and Gateway Services 
dah Morse code dash [~] 
DAMA Demand Assigned Multiple Access 
D-AMPS Digital Advanced Mobile Phone System 
DAMSON Doppler And Multipath Sounding Network 
DAQCS (1)Distress Alert Quality Control System 
DAQCS (2)Data Acquisition and Quality Control System 
DARN (1)Dual Auroral Radar Network 
DARN (2)Disaster Amateur Radio Network, SoCal 440 MHz system 
DARO Defense Airborne Reconnaissance Office 
DARP Defense Airborne Reconnaissance Program 
DARPA Defense Advanced Research Projects Agency 
DARS Digital Audio Radio Service (US) 
DARTS Dynamic Avionics Real-Time Scheduling 
DAS Data Aquisition System 
DASR Digital Airport Surveillance Radar 
DAT Digital audio tape 
DAWS Defense Automated Warning System 
DB (1)Directional Beacon 
DB (2)Dead body 
dB Decibel (1/10 Bel, a logarithmic voltage or power ratio) 
dBA Sound level (corrected to "A" scale dB) 
dBc Decibels referenced to full-rated peak envelope power 
DBCS Double byte character set 
dBd Decibel gain over dipole antenna 
dBi Decibel gain over (theoretical) isotropic antenna 
dBic Db gain over circular isotropic 
DBM (1)Doubly balanced mixer 
DBM (2)Data Block Message 
dBm Decibels over 1 mW into 50 ohms, usually rf, 0 dBm = 0.316 Vp 
DBMS Data Base Management System 
DBPSK Differential Binary Phase-Shift Keying 
DBS Direct broadcasting satellite (system) 
dBW Db over one watt 
DC Direct Current 
DC1 Device Control 1 (ASCII flow control) 
DC2 Device Control 2 (ASCII) 
DC3 Device Control 3 (ASCII flow control) 
DC4 Device Control 4 (ASCII) 
DCA (1)Defense Communications Agency (now DISA) 
DCA (2)Defensive counter Air 
DCA (3)Dual-Capable Aircraft 
DCAC Defense Communications Agency Circular (now DISA) 
DCD Data Carrier Detect (packet modems) 
DCDR Deputy Commander 
DCE (1)Data Communication Equipment (like a modem) 
DCE (2)Distributed Computing Environment 
DCG Deputy commanding general 
DCI (1)Defensive Counter Information 
DCI (2)Director of Central Intelligence 
DCID Director of Central Intelligence Directive 
DCO Defense Coordinating Officer 
DCOM Distributed Component Object Model (Windoze) 
DCCP Datagram Congestion Control Protocol 
DCP (1)Data Collection Platform 
DCP (2)Defense Cryptologic Program 
DCPA Defense Civil Preparedness Agency, now FEMA 
DCR Direct Conversion Receiver ("Homodyne") 
DCS (1)Defense Communications System 
DCS (2)Disaster Communications System, amateur, from RACES 
DCS (3)Digital Coded Squelch 
DCS (4)Distributed Control Systems 
DCT (1)Digital Communications Terminal 
DCT (2)Direct Cosine Transform 
DCTN Defense Commercial Telecommunications Network 
DCW Digital Chart of the World 
DD Dual Diversity 
DDD Maritime preamble for relayed distress message 
DDDS Defense Data Dictionary System 
DDM DoD Data Model 
DDN Defense Data Network 
DDNS Dynamic Domain Naming System/Server (Internet) 
DDO Dynamic Drive Overlay (used by Disk Manager on the PC) 
DDPO Defense Dissemination Program Office 
DDR Dual Diversity Receiver 
DDRS Defense Data Repository System 
DDR Double Data Rate (memory) 
DDS (1)Direct Digital Synthesis 
DDS (2)Defense Dissemination System 
DDT (1)Delay/Denial Technology 
DDT (2)Dynamic Debugging Tool, named for old pesticide 
DE Morse code prosign meaning "from" 
DEA Drug Enforcement Administration (US) 
DEC Digital Equipment Corporation, made some nice computers 
DECCA Low-frequency CW phase comparison navigation 
DECM Deceptive Electronic Countermeasures 
DECnet DEC's name for networking protocols and products 
DECT Digital European Cordless Telecommunications 
DEFCON DEFense CONdition, 1-5; 5 is peace, 1 is global thermonuclear war (STRATCOM) 
DEMIZ DEW East Military Identification Zone 
DEPCON Departure Control 
DE-QPSK Differentially Encoded Quaternary Phase Shift Keying 
DES Data Encryption Standard 
DES-FED Stronger (108 bit) DES used by US government 
Det Detector 
DEW Distant Early Warning (old radar in Canada) 
DF (1)Direction finding 
DF (2)Direction finder ("duffer") 
DF (3)Damping Factor 
DFAD Digital Feature Analysis Data 
DFAS Defense Finance and Accounting Service 
DFCC Digital Flight Control Computer 
DFCS Digital Flight Control System 
DFCW Dual-Frequency Continuous Wave 
DFO Disaster Field Office 
DFRC Dryden Flight Research Center (NASA) 
DGI Dirección General de Inteligencia, old name for Cuban DI 
DGM Digital group multiplexer 
DGPS-MSK Differential GPS, Minimum Shift Keying 
DGPS-QPSK DGPS-QPSK : Differential GPS, Quarternary Phase Shift 
DGS Deployable Ground Stations 
DHCP Dynamic Host Configuration Protocol 
DHFCS Defence High-Frequency Communications System (UK) 
DHS Department of Homeland Security 
DHTML Dynamic Hypertext Markup Language (web) 
DI Dirección de Inteligencia, main Cuban intelligence agcy 
DIA Defense Intelligence Agency 
DIAC Defense Intelligence Analysis Center 
DIAL Differential Absorption Lidar 
DIAM Defense Intelligence Agency Manual 
DICE Data Integration & Collection Environment 
DIDOP Digital Image Data Output Product (Differential GPS, QPSK 
DIG Domain Internet Groper 
DIGEST Digital Geographic Information Exchange Standard 
DIGI ~ Digipeater, simplex digital repeater 
DII Defense Information Infrastructure 
DIMM Double In-line Memory Module 
DIMMS Double In-line Modular Memory System 
DIN German standards agency 
DIOP Data Input/Output Port 
DIP Dual In-line Package (chips or small switches) 
Diplo Diplomatic traffic, usually encrypted 
DIPS Digital Image Processing System 
DIRCM Directed Infrared Countermeasures 
DIRMOBFOR Director of Mobility Forces 
DIS (1)Defense Investigative Service 
DIS (2)Distributed Interactive Simulation 
DIS (3)Distributed Interactive System 
DIS (4)Draft International Standard 
DIS (5)Daily Intelligence Summary 
DIS (6)Data and Information System 
DIS (7)Defense Information System 
DIS (8)Defense Intelligence Service 
DISA Defense Information Systems Agency 
DISAC Defense Information Systems Agency Circular 
DISC Packet control frame: Disconnect 
DISCO Defense Industri+al Security Clearance Office 
DISCOM Division support command 
DISN Defense Information Systems Network 
dit Morse code dot [~] 
DITAW Detect, Identify, Track, Assesment, & Warn 
DIW Dead in the water 
DIWSA Digital Imagery Workstation Suite Afloat 
DJ Deceptive Jamming 
DJBDNS Daniel J. Bernstein DNS (more secure than BIND) 
DL (1)Download 
DL (2)Data Link 
DL (3)Driver's License (police) 
DLA Defense Logistics Agency 
DLC Data Link Control 
DLE Data Link Escape (ASCII) 
DLL Dynamically Linked Library (computer programs) 
DLQ Deck Landing Qualification 
DLRP Data Link Reference Point, a USN authenticator 
DM (1)Delay Modulation (Miller Coding) 
DM (2)Packet control frame: Disconnect Mode (busy) 
DMA (1)Direct Memory Access 
DMA (2)Defense Mapping Agency 
DMAAC Defense Mapping Agency Aerospace Center 
DMAHC Defense Mapping Agency Hydrographic Center 
DMAHTC DMA Hydrographic Topographic Center 
DMAL Defense Mapping Agency List 
DMAT Disaster Medical Assistance Team 
DMATC Defense Mapping Agency Topographic Center 
DMB Digital Multimedia Broadcasting (S-DMB=Satellite, T-DMB=terrestrial) 
DMB-T/H Digital Multimedia Broadcast-Terrestrial/Handheld (China) 
DMC Defence Management Committee (Canada) 
DMCA Digital Millennium Copyright Act 
DMD Digital Micromirror Device 
DME Distance Measuring Equipment (airport approach) 
DMI Depot Maintenance Interservicing 
DMSO Defense Modeling and Simulation Office 
DMSP (1)Distributed Mail System Protocol 
DMSP (2)Defense Meteorological Satellite Program 
DMT Discrete Multi-Tone 
DMTD Digital Message Transfer Device 
DMTF Distributed Management Task Force 
DMUX Demultiplexer 
DMZ Demilitarized Zone (Korea) 
DN (1)Dutch (Royal) Navy 
DN (2)Directory Number (telco) 
DNC Digital Nautical Chart 
DNCC Deployed Network Control Center 
DND Department of National Defence (Canada) 
DNS Domain Naming System/Server (Internet) 
DNSSEC DNS Security 
DO design objective 
DOA Dead On Arrival 
DOB Date Of Birth (police) 
DOC (1)Department of Commerce (US) 
DOC (2)Department Of Communication (Canadian "FCC") 
DoD Department of Defense (US) 
DoDD Department of Defense Directive 
DoDIIS (1)Defense Intelligence Information System 
DoDIIS (2)DOD Intelligence Information System 
DODISS (3)Department of Defense Index of Specifications and Standards 
DoDISS (4)DoD Index of Specifications and Standards 
DoDSI Department of Defense Security Institute 
DoDSSP DoD Single Stock Point 
DOE Department Of Energy (US) 
DOI Department Of the Interior (US) 
DOJ Department Of Justice (US) 
DOMS Director Of Military Support (MARS) 
DOS (1)Department of State (US) 
DOS (2)Disk Operating System (generic) 
DOS (3)MS-DOS (proprietary PC op-sys) 
DOS (4)PC-DOS, IBM version of above, obsolete? 
DOS (5)Denial of Service (attack) 
DOT Department of Transportation (US) 
DOW Doppler On Wheels (storm chasing radar equipment) 
DP Development Prototype 
DPCA Displaced Phase Center Antenna 
DPCM Differential Pulse Code Modulation 
DPDT Double-Pole, Double Throw 
DPG Defense Planning Guidance 
DPL Diode-Pumped Laser 
DPSK Differential Phase-Shift Keying 
DPST Double-Pole, Single-Throw 
dpx Duplex 
DQPSK Differential Quadrature Phase-Shift Keying 
DR low drifting 
DRAC Dynamic Relay Authorisation Control 
DRAM Dynamic Random Access Memory 
DRE Drug Recognition Expert 
DRFM Digital Radio Frequency Memory 
DRFMU Digital Radio Frequency Memory Unit 
DRM (1)Digital Radio Mondiale 
DRM (2)Digital Rights Management 
DRO Dielectric Resonator Oscillator 
DRS Deployable Red Switch 
DRSN Defense RED Switch Network 
DS (1)Direct support 
DS (2)Dust storm 
DSA Division support area 
DSA/SMC Deputy for Systems Acquisition/Systems Management Center 
DSB Double sideband 
DSC Digital Selective Calling (GMDSS) 
DSI Defensive Simulation Internet 
DSL Digital Subscriber Line 
DSLAM Digital Subscriber Line Access Multiplexer 
DSM Digital Switching Module 
DSN Defense Switched Network (old AUTOVON) 
DSNET Defense Secure Network 
DSNT distant 
DSOR Depot Source of Repair 
DSP Digital signal processing 
DSR Data Set Ready (Serial I/O primary handshaking line) 
DSRC Dedicated Short Range Communications 
DSS Digital Satellite System 
Dst Disturbance Storm Time, equatorial magnetospheric activity index 
DSTO Defence Science & Technology Organisation (Australia) 
DSVD Digital Simultaneous Voice and Data 
DSVT Digital Subscriber Voice Terminal 
DSW Russian CW brevity code: "Daswedanya" (Goodbye) 
DT (1)District T (USCG) 
DTAC Division tactical command post 
DTC Design to Cost 
DTD Data Transfer Device 
DTE Data Terminal Equipment (computers, workstations, dumb terminals) 
DTED Digital Terrain Elevation Data 
DTG Date time group (example: ddhhmm mon yy z) 
DTIM Delivery Traffic Indication Message 
DTM (1)Data Text Message 
DTM (2)Data Transfer Module 
DTM (3)Digital Technology Model 
DTMB Digital Terrestrial Multimedia Broadcast (Chinese TV, nee DMB-T/H) 
DTMF Dual Tone Multi Frequency (like telco "touch tone") 
DTMF-RA Dual Tone Multi-Frequency - Remote Access 
DTO Division tactical operations center 
DTOP Digital Topographic Data 
DTR Data Terminal Ready (Serial I/O primary handshaking line) 
DTS (1)Digital Transmission System (Euro radio e-mail s/w) 
DTS (2)Data Terminal Set 
DTS (3)Digital Terrain System 
DTSS Digital Terrain Support System 
DTT Digital Terrestrial Television 
DTV Digital Television 
DU (1)widespread dust (weather) 
DU (2)depleted uranium 
DUATS Direct User Access Terminal System 
DUP-ARQ Hungarian diplomatic teleprinting system 
DUPE CW prosign: message or contact is a duplicate 
DUSD Deputy Undersecretary of Defense 
DUT1 UTC correction interval to get UT1 
DV Distinguished Visitor 
DVA Department of Veterans Administration 
DVB Digital Video Broadcast (Europe) 
DVB-S Digital Video Broadcast (satellite) 
DVB-T Digital Video Broadcast (terrestrial) 
DVB-C Digital Video Broadcast (cable) 
DVB-H Digital Video Broadcast (handheld) 
DVB-SH Digital Video Broadcast (satellite handheld) 
DVD Digital Versatile Disk 
DVFR Defense Visual Flight Rules 
DVI Digital Video Interface 
DVM Digital Voltmeter 
DVMT Dynamic Video Memory Technology 
DVP (1)Distinguished Visitor Protocol (US Air Force 
DVP (2)Digital Voice Protection (Motorola DES mode) 
DW Deutsche Welle 
DX (1)Distant Transmitter. The distance can be either geographic or psychological. 
DX (2)First transmission of FEC character 
DX (3)Duplex 
DXAC DX Advisory Committee (ARRL) 
DXCC Coveted amateur radio award, for confirming at least 100 countries 
DXing The hobby of listening to distant radio or television 
DZ (1)Drop zone 
DZ (2)drizzle 
DZST Drop Zone Support Team 
E (1)Electromotive force (in volts) 
E (2)east, ended 
E (3)E-region (middle zone of ionosphere) 
E (4)Electric field 
EA (1)East Asia (MWARA) 
EA (2)Electronic Attack 
EAC Echelons above corps 
EAD Echelons above division 
EAF Expeditionary Airfields 
EALS Emergency Airfield Lighting System 
EAM Emergency Action Message 
EARN European Academic and Research Network 
EAS (1)Emergency Alerting System, replaced EBS 
EAS (2)-----alent Air Speed 
EAS (3)Electronic Article Surveillance 
EBB Electronic bulletin board 
EBC Emulated buffer computer 
EBCDIC Extended Binary Coded Decimal Interchange Code, old IBM 
EBIOS Enhanced Basic Input/Output System (PCs with disks over 540 meg) 
EBONE A pan-European Backbone service 
EBS Emergency Broadcasting System, replaced CONELRAD 
EBU European Broadcasting Union 
EC (1)Electronic Combat 
EC (2)Emergency Coordinator 
ECB Echelons corps and below 
ECC (1)Error Correction Code (better than parity) 
ECC (2)Error Checking & Correcting (memory chip) 
ECC (3)Error Control Coding 
ECCM Electronic Counter-Countermeasures 
ECCO Electronic Combat Coordination Officer 
ECDIS Electronic Chart Display and Information System 
ECDIS-N Electronic Chart Display and Information System-Navy 
ECHS Extended Cylinder, Head, Sector (addressing) 
ECM (1)Electronic countermeasures 
ECM (2)Electronic Cipher Machine 
ECN Explicit Congestion Notification 
ECOM Emergency Communications 
ECRS East Coast Radar System 
ECS Electronic Chart System 
ed Edit; any of several funky line editors for old printing TTYs connected to computers 
EDC Error Detection Code 
EDD Electronic Document Delivery 
EDFMCM Environmental Data Fusion for Mine Countermeasures 
EDGE Enhanced Data Rates for Global Evolution (telephony) 
EDI Electronic Document Interchange 
EDO Extended Data Output (memory chip) 
EDP Electronic Data Processing 
EDPT Enhanced (fixed) Disk Parameter Table 
EDR Enhanced Data Rate 
EDS Explosives Detection Systems 
EDSAC Electronic Delay Storage Automatic Calculator (1949) 
EDT Eastern (US) Daylight Time 
EDTV Enhanced Definition Television 
edu Educational Institution domain (Internet) 
EDVAC Electronic Discrete Variable Computer (1945) 
EE (1) Transmission is in English 
EE (2) Person with Electrical Engineering degree 
EEA European Economic Area 
EEC European Economic Community 
EECEN Electronics Engineering Center, NJ (USCG) 
EEFI Essential Elements of Friendly Information (COMSEC) 
EEFI 1 Position (notification prepended by ZNX) 
EEFI 2 Capabilities 
EEFI 3 Operations 
EEFI 4 Electronic Warfare 
EEFI 5 Personnel 
EEFI 6 COMSEC breach 
EEFI 7 Wrong circuit used 
EEFI 8-10 Spare 
EEI Essential Elements of Information (Federal report form) 
EEJ Equatorial Electrojet, might cause trans-eq spread-f propagation 
EEPROM Electronically Erasable Programmable Read Only Memory 
EEZ Exclusive Economic Zone ("200-mile limit") 
EFAS Enroute Flight Advisory Service 
EFF Electronic Frontier Foundation, Internet free speech group 
EFFI Essential Elements of Friendly Information 
EFTO Encrypted for transmission only 
EGC Enhanced Group Call (GMDSS) 
EGP Exterior Gateway Protocols 
EGPRS Enhanced General Packet Radio Service 
EGS European Geophysical Society 
E-HA Enroute High Altitude 
EHS External Hostile Structured threat 
EHU External Hostile Unstructured threat 
EI-232 Latest name for RS-232, the serial interface standard 
EIA (1)Electronic Industries Association, replaced RETMA 
EIA (2)Equatorial Ionization Anomaly 
EICC Emergency Information and Coordination Center (FEMA) 
EIDE Enhanced Integrated Drive Electronics, ATA version once proprietary to WD 
EIG External Interface Gateways 
EINE EINE Is Not Emacs (recursive acronym; see Emacs) 
EIP ELINT Improvement Program 
EIRP -----alent Isotropically Radiated Power 
EIS Enhanced Imaging System 
EISA Extended Industry Standard Architecture 
EISCAT European Incoherent Scatter Radar (research) 
E-LA Enroute Low Altitude 
ELF (1) Extremely Low Frequency (30-300 Hz) 
ELF (2) US military comm system using same ("Project Elf") 
ELINT Electronic Intelligence 
elm ELectronic Mailer (Unix) 
ELSEC Electronic Security 
ELT Emergency Locator Transmitter 
ELV Expendable Launch Vehicle 
EM (1)Electromagnetic 
EM (2)Extended mission 
EM (3)Emergency management 
EM (4)End of Medium (ASCII) 
Emacs Editing Macros, powerful if ungainly, Unix text editor 
E-mail Electronic mail, usually by computer 
EMC Electromagnetic compatibility 
EMCON (1)Electromagnetic Radiation Control 
EMCON (2)Emission Control (radio, etc, not smog) 
EMCS ELINT Mission Control System 
EME (1)Electromagnetic energy 
EME (2)Earth-Moon-Earth (VHF/UHF "moonbounce") 
EMF Electromotive force (back-EMF occurs in coils & motors) 
EMI Electromagnetic incompatibility 
EMMAC European Multimedia Associations Convention 
EMP Electromagnetic pulse 
EMS (1)Extended Memory Specification (IBM PC, old LIM spec) 
EMS (2)Emergency Medical Services 
EMSEC Emanations Security 
EMT Emergency Medical Technician, public safety certificate 
EMWIN Emergency Manager's Weather Information Center 
ENC Electronic Navigational Chart 
ENE East-northeast 
ENF ELINT Notation File 
engr engineer 
ENIAC Electronic Numerical Integrator And Computer, 1940s vacuum tube calculating machine 
ENIGMA (1) European Numbers Information Gathering & Monitoring Assn 
ENIGMA (2)[~]Historic German crypto machine, WW II code broken by Allies 
ENJEP Euro-Nato Jet Pilot Training (at Sheppard AFB) 
ENQ (1)Enquiry, sent by computer to get ACK/NAK response (ASCII 05) 
ENQ (2)Enquiry (Like Who Are You?) 
ENS External Non-Hostile Structured threat 
ENTNAC Entrance National Agency Check 
ENU External Non-Hostile Unstructured threat 
EO Electro-Optical 
EO/IR Electro-Optical/Infrared 
EOB Electronic Order of Battle 
EOC Emergency Operations Center 
EOD Explosive Ordnance Disposal, the bomb squad 
EOL End of (design) life 
EO-LOROPS Electro-Optical Long Range Oblique Photography System 
EOP Emergency Operations Plan 
EOS Earth Observing System 
EOT (1)End Of Transmission 
EOT (2)End Of Tape 
EOW End Of Watch 
EP Electronic Protection 
EPA Environmental Protection Agency 
EPIC El Paso Intelligence Center (US Customs) 
EPIRB Emergency Position Indicating Radio Beacon 
EPL ELINT Parameter List 
EPLRS Enhanced Position Location Reporting System 
EPROM Electrically Programmable Read-Only Memory 
EPS (1)Emergency Planning Subcommittee 
EPS (2)Enhanced Processing Segment 
EPS (3)GOES Energetic Particle Sensor, measures solar flares 
EPU Emergency Power Unit 
EPW Enemy prisoner of war 
ER (1)Eastern Range 
ER (2)Emergency room 
ERASER Enhanced Recognition & Sensing Radar 
ERFAK Emergency Response Fly-Away Kit (US Govt) 
ERLink Emergency Response Link (US Govt) 
ERMA Electronic Recording Machine Accounting (1959, first check reader) 
erp Effective radiated power 
ERPS External Frequency Interference Protection System 
ERT Emergency Response Team (FEMA) 
ERT-A Advance Element of the Emergency Response Team (FEMA) 
ERTS Earth Rotation Time Service, keeps track of planet's actual position in space 
ES (1)Electronic Support 
ES (2)CW brevity code: "And" 
ES (3)Sporadic E propagation, or clouds making same 
ESA European Space Agency 
ESC (1)Enhanced Satellite Capability (US NCS) 
ESC (2)Escape (computer character) 
ESE East-southeast 
ESF Emergency Support Function (part of NTSP; 1-12) 
ESM Electronic Support Measures 
ESMC Eastern Space & Missile Center 
ESMTP Extended Simple Mail Transfer Protocol (does this mean it's no longer simple?) 
ESN Electronic Serial Number 
ESS (1)Electronic Switching System (landlines) 
ESS (2)Electronic Scoring Site 
EST (1)Eastern (US) Standard Time 
EST (2)Emergency Support Team (FEMA) 
ET (1)Extra-terrestrial 
ET (2)External Tank (NASA) 
ET (3)Eastern Time (US) 
ETA Estimated time of arrival 
ETB End of Transmission Block 
ETD (1)Estimated time of departure 
ETD (2)End-of-Train Device 
ETD (3)Explosives Trace Detection 
ETLA Extended Three-Letter Acronym (a four-letter acronym) 
ETOH Alcohol (for some reason, paramedics say the chemical name) 
ETRAC Enhanced Tactical Radar Correlator 
ETSI European Telecommunications Standards Institute 
ETX End Of Text (ASCII) 
EUCOM European Command 
Eunet European part of UUCP, Unix file transfer network 
EUR Europe (MWARA) 
EUV Extreme ultraviolet (can ionize) 
EVS Electro-Optical Viewing System 
EW Electronic warfare 
EWIR Electronic Warfare Integrated Reprogramming 
EWMS Electronic Warfare Management System 
EWN Evangelical World Network, operates WEWN 
EWO (1)Electronic Warfare Officer (backseater) 
EWO (2)Emergency War Order 
EWPE EW Processing Element 
EWR Early Warning Radar 
EWS Early Warning System 
EXE Computer file extension: loads as executable 
EXE2BIN PC program for creating .COM files from .EXE 
f Frequency (in Hertz) 
F (1)Farad (a huge capacitor; usually uf or pf) 
F (2)F-region, highest zone of ionosphere 
F1 (1)In daytime, lower layer of F region 
F1 (2)Frequency number one (F2, F3...) 
F2 In daytime, upper layer of F region 
F/B Front to back ratio (antennas) 
F/O (1)Fiber optics 
F/O (2)Follow-on 
F/V Fishing Vessel 
F/W Fixed wing (airplane) 
F0 FM carrier, no modulation, sounds just like A0, now N0N 
F1B Mode designator: frequency shift keying 
F2B Mode designator: Audio frequency-shift keying 
F3C Mode designator: fax 
F3E Mode designator: FM voice or broadcasting 
FAA (1)Federal Aviation Administration (US) 
FAA (2)Foreign Assistance Act 
FAAA General call: "All French warships" [~] 
FAADC3 Forward Area Air Defense Command, Control, Communications Intelligence System (US Army) 
FAC (1)Field-Aligned Current, an irregular propagation mode 
FAC (2)Forward Air Controller 
FACSFAC Fleet Area Control & Surveillance Facility (US Navy) 
FADEC Full Authority Digital Engine Control 
FAE Fuel Air Explosive 
FAF (1)Fast Access Format 
FAF (2)French Air Force 
FAGDS Federation of Astronomical and Geophysical Data Services 
FAI Field-Aligned Irregularities, like FAC 
FAM Federal Air Marshal 
FAPSI Federal Agcy for Govt Comm & Info (Russian, replaced KGB) 
FAQ Frequently Asked Questions (Internet/USENET) 
FAR Federal Aviation Regulations 
FARP Forward Arming & Refueling Point 
FAS (1)Frequency Assignment Subcommittee (of IRAC) 
FAS (2)Federation of American Scientists 
FASC Forward area signal center 
FAST (1)Field Assessment Team (FEMA) 
FAST (2)Fleet Antiterrorist Strike Team (US Marines) 
FAST (3)Fast Auroral Snapshot Small Explorer satellite (NASA) 
FAST Field Adaptable Systems Technology 
FAT (1)File Allocation Table (MS-DOS) 
FAT (2)First Article Test 
FAT32 32-bit File Allocation Table (Newer MS-Windows) 
FAX Facsimile 
FB CW brevity code: "Fine Business" (really good) 
FBI Federal Bureau of Investigation (US) 
FBO Fixed Base Operator 
FC funnel cloud 
FCC Federal Communications Commission 
FCMP Fleet Composite Broadcast (USCG Honolulu) 
FCO Federal Coordinating Officer (FEMA) 
FCS Frame Check Sequence (wi-fi) 
FD (1)Floppy Disk 
FD (2)Fixed Disk (confusing!) 
FDD Floppy Disk Drive 
FDDI Fibre Data Distribution Interface 
FDK Frequency-Difference Keying 
FDM Frequency-Division Multiplex 
FDMA Frequency Division Multiple Access 
FDPT Fixed Disk Parameter Table 
FDX Full Duplex 
FEBA Far East Broadcasting Assn 
FEC Forward error correction teleprinter system 
FEC-A One-way traffic FEC teleprinter system 
FECC Federal Emergency Communications Coordinator 
FECTOR Teleprinting over radio, mode B 
FED-STD Federal Telecommunication Standard 
FEK Frequency Exchange Keying 
FEMA Federal Emergency Management Agency 
FEP (1)Front End Processor (computers) 
FEP (2)FLTSAT EHF Package (Navy) 
FET Field-effect transistor 
FEW Few clouds 
FF (1)French Forces 
FF (2)Transmission is in French 
FF (3)Formfeed (ASCII) 
FFH (1)Fast Frigate Helicopter 
FFH (2)Fast Frequency Hopping (spread spectrum scheme) 
FFHT-net Fast-Frequency-Hopping Training net 
FFRDC Federally Funded Research& Development Center (MITRE Corp.) 
FFT Fast Fourier transform 
FG (1)Foreign Government (Foxtrot Golf) 
FG (2)Fog 
FGS Federal German Ship 
FH Field hospital 
FHWA Federal Highway Administration (US) 
FI Field Investigation, Field Interview (police) 
FIA (1)Fibreoptic Industry Association (UK) 
FIA (2)Federation Internationale d'Automobile (Formula 1 racing) 
FIBI filed but impracticable to transmit 
FIFO First in, first out 
FIGS Figures case (Baudot upper case) 
figs figures follow 
FIM Flight Information Manual 
FINDS Flexible Information Dissemination System 
FIPS Federal Information Processing Standards 
FIR (1)Flight Information Region 
FIR (2)Finite Impulse Response 
FIRESCOPE Firefighting Resources of Southern California Organized for Potential Emergencies 
FIRRS FAAR/Iceland Air Defense Remote Rekeying System 
FIRST (1)Forum of Incident Response and Security Teams (computers) 
FIRST (2)first observation after a break in coverage at manual station 
FISIN Foreign Instrument Signals Intelligence 
FISINT Foreign Instrumentation Intelligence 
FIST Fleet Imagery Support Terminal (US Navy) 
FISTA Flying Infrared Signatures Technology Aircraft 
FITFEEL Fast Information Transfer For Extremely Errored Links 
FL (1)Flight level 
FL (2)Focal Length 
FLAK German: FLeigerAbwehrKannonen (anti-aircraft artillery) 
FLASER Forward Looking Infrared Laser Radar 
FLIP Flight Information Publication (US DoD) 
FLIR Forward looking infrared 
Flops Floating point operations per second 
FLOT Forward Line of Own Troops 
FLOTUS First Lady Of The United States (President's wife) 
FLR Forward looking radar 
FLT HICOM Fleet High Command, (US Navy) 
Flt (1)flight 
Flt (2)fleet (US Navy) 
FLTSAT Fleet Satellite, Navy comsat 
FLTSATCOM Fleet Satellite Communications (US Navy) 
FM (1)Frequency Modulation 
FM (2)Field manual 
FM (3)("Foxtrot Mike") VHF FM (US Navy) 
FM (4)CW brevity: From 
FM (5)Field Meteorological 
FMA-net Frequency Management A-net 
FMH Federal Meteorological Handbook 
FMH-1 Federal Meteorological Handbook-1 
FMH-2 Federal Meteorological Handbook No.2 
FMO Frequency Management Office 
FMOW FM Orderwire (US military) 
FMP Fleet Modernization Program 
FMS Foreign Military Sales 
FMT-net Frequency Management Training net 
FN French Navy 
FNG Friendly new guy/gal (possible security risk) 
FNPRM Further Notice of Proposed Rule Making (FCC) 
FOB (1)Field Operations Bureau (FCC) 
FOB (2)Freight On Board (shipping regs) 
FOB (3)"Fresh Off the Boat" (humorous) 
FOD Foreign Object Damage 
FOIA Freedom of Information Act 
FOLDOC Free Online Dictionary Of Computing 
FORSCOM Forces Command 
FORTRAN Formula Translator (early IBM computer language) 
FOSIC Fleet Ocean Surveillance & Information Center 
FOT Optimum Traffic Frequency (fq that will work most days of period) 
FOUO For Official Use Only 
FOV Field of View 
Foxes THE QUICK BROWN FOX... test [~] 
FPLMTS Future Public Land Mobile Telecommunications Systems 
FPM Fast Page Mode 
FPO Fleet Post Office 
Fq Frequency 
FQDN Fully Qualified Domain Name (Internet) 
FQPSK Filtered Quadrature Phase Shift Keying 
FR (1)Frequency Response 
FR (2)Final report 
FRA (1)Forward repair activities 
FRA (2)Federal Request for Assistance (FEMA) 
FRA (3)Fixed Radio Access 
FRCM Federal Regional Coordinating Manager (FEMA) 
Freq Frequency 
FRMR Packet control frame: Frame Reject 
FRN (1)FCC Registration Number 
FRN (2)Free Radio Network 
FROPA frontal passage 
FRP (1)Federal Response Plan (FEMA) 
FRP (2)Fleet Response Plan 
FRQ frequent 
FRS Family Radio Service 
FS File Separator (ASCII) 
FS-1037C Official Federal Telecom Glossary, replaced by ATIS 
FSB Forward support battalion 
FSBS (Consolidated) Fixed Submarine Broadcast System 
FSC Full Scope Command (USAF HF Phase II) 
FSD Federal Security Director 
FSE Fire support element 
FSF Free Software Foundation 
FSK Frequency-shift keying 
FSL Forecast Systems Laboratory 
FSM Facility Status Message 
FSOC Fairchild Satellite Op Center, Fairchild AFB, WA 
FSP (1)File Service protocol (Internet) 
FSP (2)File Slurping Protocol 
FSP (3)Flaky Stream Protocol 
FSP (4)FTP's Sexy Partner 
FSRAM Fast Static Random Access Memory 
FSS Fixed-Satellite Service 
FST Forward surgical team 
FSTS Federal Secure Telecommunications System 
FSU Former Soviet Union 
FT (1)Terminal Forecast (weather) 
FT (2)Feet 
ft foot 
FTA F--- The Army 
FTAM File Transfer Access and Management 
FTG F--- The Guard 
FTI Fixed Target Indicator 
FTP File Transfer Protocol 
FTS Federal Telephone System 
FTW F--- The World 
FU Smoke (from French) 
FUBAR [Fouled] Up Beyond All Recognition 
FUD Fear, Uncertainty, Doubt (computer marketing technique) 
FV Fishing Vessel 
FVLF Fixed, Very Low Frequency 
FW Fighter Wing (USAF) 
FWA Fixed Wireless Access 
fwd forward 
FWE Fighter Wing -----alent 
FWIW For What It's Worth 
FWOC Fleet Weather and Oceanographic Centre (UK) 
FY Fiscal Year 
FYEO For Your Eyes Only 
FYI For your information 
FZ freezing 
FZRANO freezing rain sensor not available 
G (1)Conductance, reciprocal of R, in mhos, ohm backwards 
G (2)Gust 
G/T "G over T", antenna gain divided by noise temperature 
G1 Asst. Chief of staff, personnel (US Army) 
G2 Asst. Chief of staff, intelligence (US Army) 
G3 Asst. Chief of staff, operations and plans (US Army) 
G4 Asst. Chief of staff, logistics (US Army) 
G5 Asst. Chief of staff, civil affairs (US Army) 
G6 Asst. Chief of staff, information mgmt. (US Army) 
GA (1)CW prosign: go ahead 
GA (2)CW brevity code: Good Afternoon 
GaAs Gallium Arsenide 
GaAsFET Gallium Arsenide Field Effect Transistor 
GACC Geographic Area Coordination Centers (USFS) 
GAFRAN Stationary German Air Force 
GAK Government Access to Key 
GALEX Galaxy Evolution Explorer (NASA) 
GaN Gallium Nitride 
Gantsec Greater Antilles Section (US military/federal, out of Puerto Rico) 
GAO General Accounting Office (US Government) 
GATM Global Air Traffic Management 
GATR ground-to-air transmitter/receiver 
GATX General American Transportation Corporation, tank & hopper car lessor 
GBDL Ground Based Data Link 
GBI Ground-Based Interceptor 
GBL Ground-Based Laser 
Gbps Gigabytes per second 
GBR Ground Based Radar 
GBS (1)Global Broadcast System 
GBS (2)Ground Based Sensor 
GCA Ground Controlled Approach 
GCAS Ground Collision Avoidance System 
GCBS Ground Control Bombing System 
GCC Ground Component Commander 
GCCS (0)Two different systems: 
GCCS (1)Global Command Control System, obsolete US Air Force 
GCCS (2)Global Command & Control System, 1992 data network plan to replace WWMCCS computers 
GCHQ Government Communication Headquarters ("G;" UK comint) 
GCMP Guam Composite Broadcast (obsolete USCG) 
GCN (1)ground communications network 
GCN (2)ground control network 
GCSS Global Combat Support System 
GD CW brevity: Good Day 
GDIP General Defense Intelligence Program 
GDO Grid/Gate Dip Oscillator 
GDOC Geographical Display Operations Computer 
GDR Ground Data Reduction 
GDSS Global Decision Support System 
GE (1)General Electric 
GE (2)CW brevity: Good Evening 
GE (3) Guerra Elettronica (Italian for Electronic Warfare) 
GENSER (1)General Security Regulations 
GENSER (2)general service 
GENTEL General Telephone Company 
GEO Geosynchronous Earth Orbit 
GEODSS Ground-based electro-optical deep space surveillance 
GEOS (1)Geodynamic experimental ocean satellite 
GEOS (2)Geomagnetic earth observation system 
GEOS (3)Graphic Environment Operating System 
GEP Ground Entry Point 
GES Ground Earth Station 
GETS Government Emergency Telecommunications Service (US NCS) 
GFA Graphical Area Forecast 
GFAE Government-furnished aerospace equipment 
GFDL Geophysical Fluid Dynamics Laboratory 
GFE (1)Government-furnished equipment 
GFE (2)God-Furnished Equipment (ionosphere) 
GFI (1)Government-furnished information 
GFI (2)Ground Fault Interrupter 
GFM Government-furnished material 
GFP (1)Government Furnished Property 
GFP (2)Government-furnished part 
GMSK Gaussian Minimum Shift Keying 
GG Transmission is in German 
GHFS Global High Frequency System (US Air Force) 
GHz GigaHertz 
GI (1)Government Issue 
GI (2)Old slang, from above: U.S. soldier 
GID Group Identification 
GIF Graphics Interchange Format, first used on CompuServe 
GIGO Garbage In, Garbage Out; first rule of computing 
GIMP GNU Image Manipulation Program, a nested acronym 
GIS Geographical Information System 
GKS Graphical Kernel System 
GLOB Ground Loving Old B-----d (KC-135) 
GLONASS Global Navigation Satellite System (Russian GPS) 
GM (1)CW brevity code: Good Morning 
GM (2)General Motors 
GM (3)General Manager 
GM (4)Guided Missile 
GMDSS Global Maritime Distress & Safety System 
GMF (1)Ground Mobile Force 
GMF (2)Government Master File (frequencies) 
GMI General Military Intelligence 
GMRS General Mobile Radio System 
GMS Geostationary Meteorological Satellite (Japanese) 
GMT (1)Greenwich Mean Time (obsolete, still UK's name for standard time) 
GMT (2)Ground Moving Target 
GMTI Ground Moving Target Indication 
GNA Gulf News Agency 
GNC (1)guidance and navigation computer 
GNC (2)guidance, navigation and control 
gnd ground 
GNDCON Ground Control 
gnu Gnu's Not Unix, a freeware op-system (recursive acronym) 
GO General Officer 
GOA Gone on Arrival (police) 
GOES (1)Geosynchronous Oceanic & Environmental Satellite 
GOES (2)Geostationary Operational Environmental Satellite 
GOGO government-owned, government-operated 
GOJ Government of Japan 
GORIZONT Moscow State University Geostationary Monitor satellite 
GOSIP Government Open Systems Interconnection Profile (UK & US) 
GOTS Government-off-the-shelf 
gov Government site (Internet) 
GOWON Gulf Offshore Weather Observing. Network 
gp Group 
GPM Gallon(s) per minute 
GPO (1)Government Printing Office (US) 
GPO (2)General Post Office 
GPR Ground Penetrating Radar 
GPRS General Packet Radio Service 
GPS Global Positioning System 
GR Hail (from French) 
GRADU Gradual weather change 
GRC General Radio Communications (AN/GRC-xxx) 
GRDCUS Gulf Range Drone Control Upgrade System 
grep Global Regular Expression, Print; Unix text search 
GRI Group Repetition Interval (Loran) 
grp Group 
GRT Gross register tonnage 
GS (1)General support 
GS (2)Group Separator (ASCII) 
GS (3)small hail and/or snow pellets 
GS (4)Ground Stop 
GS (5)Ground Station 
GSA General Services Administration (US) 
GSAC Ground support associate contractor 
GSC (1)Ground systems controller 
GSC (2)Ground support contractor 
GSCO Ground systems control officer 
GSD General support division 
GSE Ground support equipment 
GSF GPS support facility 
GSFC Goddard Space Flight Center, Greenbelt, MD 
GSM Global System for Mobile communications 
GSMP General Switch Management Protocol 
GSO Geostationary Satellite Orbit 
GSTS Ground-based surveillance and tracking system 
G-SWF Gradual Shortwave Fadeout (ionospheric disturbance) 
GTC Greek Telegraphy Club, aka SV-CW-C 
GTK GIMP Tool Kit, a deeply nested acronym 
gTLD generic top-level domain 
GTO (1)geosynchronous transfer orbit 
GTO (2)fast car made by Ferrari ("Gran Turisimo Omologato") 
GTO (3)not quite so fast car made by Pontiac 
GTOC Geosynchronous transfer orbit capability 
G-TOR Golay Transmissions Over Radio (Kantronics version of PACTOR) 
GTS Global Telecommunication System (WMO) 
GUHOR Informal: "I don't hear you" (Loosely, from Russian prosign) [~] 
GUHOR Stick (1)Informal: Net diagramming tool used in Cold War COMINT 
GUHOR Stick (2)Wouff Hong substitute (see Wouff Hong) 
GUI Graphical User Interface 
GUID Globally Unique Identifier 
GVAR GOES Variable 
GW (1)Gigawatt 
GW (2)CW brevity code: Good Evening 
GW (2)Ground wire 
GWARC General World Administrative Radio Conference 
GWEN Ground wave emergency network (VLF strategic net) 
GWT Gross Weight Tonnage 
H (1)Henry (unit of inductance) 
H (2)Magnetic field 
h/w Hardware 
H24 All 24 hours; station operates continuously 
HA ("Hotel Alpha") human remains 
HAARP HF Active Auroral Research Program 
HAAT Height Above Average Terrain 
HAC (1)higher authority communications(USAF) 
HAC (2)heading alignment circle (NASA) 
HAC (3)Hughes Aircraft Company 
HAES High Altitude ELINT System 
HAF Headquarters Air Force 
HAL (1)High-order Assembly Language (space shuttle computers); named for: 
HAL (2)Heuristically programmed Algorithmic Computer (2001: A Space Odyssey) 
HAMP Horizontal Avionics Modernization Planning 
HAMS Hilltop Amateur Mastertie System; old, big SoCal 440 MHz system 
HAR Highway Advisory Radio 
HARCO Harris Radio Company, makes HF setups 
HARM High-Speed Anti-Radiation Missile 
HAS Hardened Aircraft Shelter 
HASA High Altitude SIGINT Architecture 
HBD (1)Has Been Drinking (police) 
HBD (2)Hot Box Detector (railroad) 
HBI Horizontal Blanking Interval (TV) 
HBO Home Box Office (TV network) 
HBS Heart Beat Signal (Australian Internet) 
HBT Heterojunction Bipolar Transistor 
HBT Heterojunction Bipolar Transistor 
HC-ARQ Hagelin-Cryptos simplex teleprinter system 
HCI Human-Computer Interface 
HE-AAC High-Efficiency Advanced Audio Coding 
HCJB Heralding Christ Jesus' Blessing (callsign) 
HCP Health and comfort package 
HD (1)Hard Disk 
HD (2)High Density 
HD (3)High Definition 
HDB High-Density Bipolar 
HDD (1)Hard Disk Drive 
HDD (2)Heads Down Displays 
HDLC High-level Data Link Control, old synchronous computer protocol 
HDOP Horizontal Dilution of Precision (DGPS) 
HDR High Data Rate 
HDS Hard Disk Subsystem 
HDSL High-rate Digital Subscriber Line 
HDTV High-Definition Television 
HDX Half-duplex 
HE (1)high energy 
HE (2)high explosive 
HEAR Hospital Emergency Alert Radio (SoCal) 
HEMP High-altitude electromagnetic pulse 
HEMT High-electron-mobility transfer 
HEMTT Heavy expanded mobility tactical truck 
HEO (1)high earth orbit 
HEO (2)highly elliptical orbit 
HEP Head End Power (railroad locomotives) 
HERE Hazards of Electromagnetic Radiation to Equipment 
HERF High-Energy RF (weapons) 
Hertz Unit of frequency, named for Heinrich Hertz, 1Hz=1 cps 
HES Hurricane Evacuation Study 
HETS (1)heavy equipment transporter system 
HETS (2)heterodynes [~] 
Hex Hexadecimal number notation, base 16 
HF High Frequency (3-30 MHz) 
HFBC High-Frequency broadcasting 
HFCC High-Frequency Coordination Conference 
HFDL High-Frequency Data Link, single-tone digital aero mode 
HFDLP HF Data Link Protocol 
HFDR HF Data Radio 
HFDU HF Data Unit 
HFGCS High Frequency Global Communication System (Scope Command) 
HFIA HF Industry Association 
HFMOD Australian Defence Force High Frequency Modernisation Project 
HFNC HF Network Controller 
HFNPDU HFDL: High Frequency Network Protocol Data Unit 
HFO (1)High-Frequency Oscillator 
HFO (2)Honolulu Forecast Office 
HFS Hierarchical File System 
HFSWR High-Frequency Surface-Wave Radar 
HHS (Dept. of) Health & Human Services 
HHT (1)Hand-Held Terminal 
HHT (2)Hand-Held Tester 
HI CW brevity code: a laugh (all dits, easier to send than "HA") 
HICOM High Command net (US Navy) 
HIDAR High Data Rate 
HIFER High-Frequency Experimental Radio (low-power ~13.5 MHz) 
Hi-fi High Fidelity (audio) 
HIPAS High-Power Auroral Stimulation 
HIPPI High Performance Parallel Interface 
HIRF High Intensity Radiation Fields 
HISCAT High-latitude, High-altitude, High-power, High-frequency, High-performance, Heating and ionospheric Scatter facility (research) 
HITRON Helicopter Interdiction Tactical Squadron (US Coast Guard) 
HIWAS Hazardous Inflight Weather Advisory Service 
HJ ("Hotel Juliet") Hijack 
HK Handle Key (Windows registry) 
HKCC Handle Key, Current Configuration (Windows registry) 
HKCR Handle Key, Classes, Root (Windows registry) 
HKCU Handle Key, Current User (Windows registry) 
HKDD Handle Key, Dynamic Data (Windows registry) 
HKEY Handle to a KEY (Windows Registry) 
HKG Hong Kong (old country code) 
HKLM Handle Key, Local Machine (Windows registry) 
HKTI Hong Kong Telecom International 
HKU Handle Key, Users (Windows Registry) 
HM Her Majesty 
HMCS Her Majesty's Canadian Ship 
HMMWV High mobility, multipurpose wheeled vehicle (hummvee) 
HMS Her Majesty's Ship 
HND Honduras (country code) 
HNG Hungary (country code) 
HNG-FEC Hungarian diplo FEC teleprinting system 
HNMP HF Network Management Protocol 
HNS Host nation support 
HOLF Helicopter Outlying Landing Field 
HP (1)High Pass (filter circuit) 
HP (2)Highway Patrol 
hp Horsepower 
Hpa Hectopascal 
HPC Hydrometeorological Prediction Center, MD 
HPE CW brevity code: "Hope to..." 
HPG Hardcopy Processor Group 
HPI High-Priority Intercept (global HF comint system) 
HPM High Power Microwave 
HPTS High-Power Transmitting System (TACAMO) 
HQ Headquarters 
HQAN HAVE QUICK A-Net 
HQDA Headquarters, Department of the Army 
HR High Resolution 
hr Hour 
HR Hybrid Receive 
HRC Harmonically Related Carrier (CATV channel scheme) 
HRCS High Resolution Camera System 
HRMP HF Relay Management Protocol 
HRPT High Resolution Picture Transmissions 
HRR High Resolution Radar 
hrs Hours 
HRT Hostage Rescue Team (FBI) 
HRT Hrvatske Radio Televizije (Croatian) 
HRV Croatia (country code) 
HSAL High Speed Algebraic Logic 
HSFB High Speed Fleet Broadcast 
HSI Hyperspectral Imaging 
HSIP H Camera Sensor Improvement Program 
HSSP HF Station Status Protocol 
HST (1)Hawaiian Standard Time 
HST (2)Hubble Space Telescope 
HT (1)Handie-talkie, a hand-held radio 
HT (2)Horizontal Tab (ASCII) 
HTI (1)Haiti (country code) 
HTI (2)Hostile Target Identification 
HTML Hypertext Markup Language (world wide web) 
HTS High Temperature Superconducting 
HTTP HyperText Transmission Protocol (WWW) 
HTTPD HTTP Daemon (Unix) 
HTTP-NG HTTP Next Generation 
HTTPS (1)HTTP Server 
HTTPS (2)HTTP with Secure Sockets Layer 
HUD Heads-up Displays 
HULTEC Hull to Emitter Correlation 
HUMINT Human Intelligence (spies!) 
HVAR High-Velocity Aerial Rocket 
HW CW brevity code: "How do you copy me?" 
hx Signal is a harmonic 
HYDROLANT US warnings for Atlantic and east 
HYDROMET Hydro-Meterological bulletin or warning 
HYDROPAC US warnings for Pacific Ocean and west 
Hyperfix Hyperbolic Radio Navigation System (proprietary name) 
HZ haze 
Hz Hertz (a "cycle per second") 
I (1)Current (in amperes, amps) 
I (2)Packet designator: information frame 
I (3)Italy (country code) 
I/O Input/Output (computers) 
i18n Alphabet scheme for multi-lingual computer programs [~] 
IA (1)Information Assurance 
IA (2)Italian Army 
IA (3)Short for IATSE, the movie/theatrical production union 
IA (4)Information Attack 
IAAFA Inter-American Air Forces Academy 
IAB Internet Architecture Board 
IAC International Analysis Code (weather codes FM-45, FM-46) 
IADS Integrated Air Defense System 
IAEM International Association of Emergency Managers (was NCEM) 
IAF Italian or Irish air force 
IAG Imagery Analysis Group 
IAGA International Association of Geomagnetism and Aeronomy 
IAIP Information Analysis and Infrastructure Protection 
IANA Internet Assigned Numbers Authority 
IAP International AirPort 
IAPS I Am Pretty Sure 
IARN International Amateur Radio Network 
IARP International Amateur Radio Permit (to operate overseas) 
IARU International Amateur Radio Union 
IAS (1)Image Access Service 
IAS (2)Indicated Air Speed 
IAS Intelligence Analysis System 
IATA International Air Transport Association 
IAU International Astronomical Union 
IAVTR Integrated Audio Visual Transmitter/ Receiver 
IAW In accordance with 
IBC (1)International Broadcast Center (Olympics) 
IBC (2)Italian Broadcasting Corporation 
IBCT Initial Brigade Combat Teams 
IBDL Inter Battery Data Link 
IBM (1)International Business Machines (company) 
IBM (2)de facto PC standard, though few are true blue 
IBOC In-band, on-channel (digital broadcasting) 
IC (1)Integrated circuit (chip) 
IC (2)Incident Command 
IC (3)Ice crystals 
IC (4)In-cloud lightning 
ICAO International Civil Aviation Organization 
ICAP Internet Calendar Access Protocol 
ICAS Intermittent Commercial and Amateur service (rating) 
ICBM Intercontinental Ballistic Missile 
ICD Interface Control Document 
ICE (1)Immigration and Customs Enforcement 
ICE (2)Intrusion Countermeasures Electronics 
ICIS Interagency Communications Interoperability System (SoCal) 
ICM Intelligence Correlation Module 
ICMP Internet Control Message Protocol 
ICNIA Integrated Communications Navigation IFF Avionics 
ICNIS Integrated Communication Navigation and ID System 
ICOM (1) Intercom 
ICOM (2) Japanese radio mfr [~] 
ICOM (3) Integrated COMSEC 
ICON Image Communication and Operations Node 
ICP Internet Cache Protocol 
ICPO International Criminal Police Organization, see INTERPOL 
ICQ "I Seek You" (Internet message program) [~] 
ICRC International Committee of the Red Cross 
ICS Incident Command System 
ICSTIS Independent Committee for the Supervision of Standards of Telephone Information Services (UK) 
ICW interrupted continuous wave 
ID (1)Identification 
ID (2)Inside Diameter 
IDAS Integrated Air Defense System 
IDASS Integrated Data Analysis System for Spacecraft 
IDCP ID Data Combining Process 
IDE (1)Intelligent Drive Electronics (small HD standard) 
IDE (2)Integrated Developer Environment 
IDEA International Data Encryption Algorithm 
IDECM Integrated Defensive ECM 
I-DGS Interim-Deployable Ground Station 
IDLH Immediate Danger to Life and Health 
IDLM Interference Detection, Locating, and Mitigation 
IDM Improved Data Modem 
IDN Internationalized Domain Names 
IDPS Interim Digital Processing System 
IDSL ISDN Digital Subscriber Line 
IEC International Electrotechnical Commission 
IED (1)Improvised Explosive Device 
IED (2)Imitative electronics deception 
IEE (1)Institute of Electrical Engineers (US), merged with IRE 
IEE (2)Institution of Electrical Engineers (UK) 
IEEE Institute of Electrical & Electronics Engineers 
IETF Internet Engineering Task Force 
IF Intermediate Frequency (of a receiver) 
IFE Inflight emergency 
IFF (1)Identification, Friend or Foe 
IFF (2)Logic operation: "if and only if" 
IFIM International Flight Information Manual 
IFK Incremental Frequency Keying 
IFL International Frequency List, ITU doc on fiche or 2 CDs 
IFOR Implementation Force ("UN peacekeepers") 
IFP Image Formation Processor 
IFPS Interactive Forecast Preparation System 
IFR (1)Instrument Flight Rules 
IFR (2)"I Follow Roads" 
IFRB International Frequency Registration Board 
IFRC Int'l Federation of Red Cross/Red Crescent 
IFSAR Interferometric Synthetic Aperture Radar 
IGBT Insulated Gate Bipolor Transistor 
IGDL Interoperable Ground Data Link 
IGMP Internet Group Management Protocol 
IGMP Internet Group Management Protocol 
IGP Interior Gateway Protocols 
IGRP Interior Gateway Routing Protocol 
IGY International Geophysical Year, big 50's research interval 
IHFR Improved high frequency radio 
IHO International Hydrographic Organization 
IHS Internal Hostile Structured threat 
IHU Internal Hostile Unstructured threat 
IL Intermediate Language (Object-oriented computing) 
ILC Integral Locomotive Computer (railroad) 
ILS Instrument Landing System 
IM (1)Intermodulation, causes spurious signals or distortion 
IM (2)Integrity Monitor (DGPS) 
IMA Individual Mobilization Augmentee (FEMA) 
IMAP Internet Message Access Protocol 
IMC Internet Mail Consortium 
IMD Intermodulation Distortion 
IMETS Integrated Meteorological System 
IMHO In My Humble Opinion (Internet) 
IMI CW prosign: interrogative; more often written "?" 
IMINT Imagery Intelligence 
IMIS Integrated Maintenance Information System 
IMM Image Manifest Message 
IMN Iraqi Media Network 
IMO (1)International Maritime Organization, part of UN 
IMO (2)In My Opinion (Internet) 
IMS Integrated Maritime Surveillance 
IMSA International Municipal Signal Association 
IMSI International Mobile Subscriber Identity 
IMSP Internet Message Support Protocol 
IMTS Improved Mobile Telephone System 
IN (1)Intelligent Network 
IN (2)Indian Navy 
IN (3)Intelligence 
in inch 
INA Iraqi News Agency 
IND India (country code) 
indiv individual(s) 
INEFC Interagency National Emergency Fire Cache 
INFOSEC Information systems security 
ING International Notification Group(of IRAC) 
inHg inch of Mercury (air pressure) 
INMARSAT Intl. Maritime Satellite Org, a consortium, leases bandwidth on Marecs, Intelsat, Marisat for ship use. 
INMARSAT-A Inmarsat mobile voice/data terminal 
INMARSAT-B Improved version, replaced A 
INMARSAT-C Data-only INMARSAT terminal, also for SAFETYnet 
INMARSAT-E INMARSAT EPIRB 
INMARSAT-M INMARSAT terminal, voice only, not GMDSS-compliant 
INO Indian Ocean (MWARA) 
InP Indium Phosphide 
INS (1)Immigration & Naturalization Service (US, now part of ICE) 
INS (2)Inertial Navigation System 
INS (3)Indonesia (country code) 
INS (4)Internal Non-Hostile Structured threat 
INSCOM US Army Intelligence and Security Command 
INT (1)Interrogative (precedes a question) 
INT (2)International 
INT (3)Interrupted (transmission) 
INT (4)Interrupt (computer processing) 
intel Intelligence 
INTELCAST Intelligence Broadcast 
INTELNET Intelligence Network 
Internet Global interconnection of regional nets using TCP/IP 
InterNIC Internet Network Information Center 
INTERPOL International Criminal Police Organization 
Intl International, internal 
INU Internal Non-Hostile Unstructured threat 
IOC Index of co-operation (a fax parameter) 
IOD Issue Of Data (DGPS) 
IOM Installation, operation and maintenance 
IONCAP IONospheric Communications Analysis and Prediction, original prediction algorithm, still used 
IOR Indian Ocean Region 
IOS Indian Ocean Station (NASA) 
IP Internet Protocol 
IPA Intermediate power amplifier 
IPB Intelligence Preparation of the Battlefield 
IPCP Internet Protocol Control Protocol 
IPF Intelligence Processing Facility 
IPI Intelligent Peripheral Interface 
IPIR Initial Photo Interpretation Report 
IPIX Interface Processor for Imagery Exchange 
IPL Image Product Library 
IPng IP next generation 
IPS (1)Inches per second 
IPS (2)Ionospheric Prediction Service (Australia, original name for space weather agcy) 
IPSec Internet Protocol Security 
IPSS International Packet SwitchStream, now GNS (UK) 
IPT Integrated Program Team 
IPTV Television via IP protocol (Internet TV) 
IPX Internetwork Packet Exchange (Novell) 
IQ In-phase/Quadrature (analyzer plot) 
IQSY International Year of the Quiet Sun, 1960's research interval 
IR (1) Infrared 
IR (2) Instrument route (numbered military training route) 
IRA International Reference Alphabet 
IRAC Interdepartment Radio Advisory Committee (part of US NTIA) 
IRBM Intermediate Range Ballistic Missile 
IRC (1)International Reply Coupon 
IRC (2)Internet Relay Chat, world's primo time waster 
IRC (3)International Red Cross 
IRC (4)Incrementally Related Carrier (CATV channel scheme) 
IRC (5)International Record Carrier 
IRCA International Radio Club of America 
IRCCM Infrared Counter-Countermeasures 
IRCM Infrared Countermeasures 
IRE Institute of Radio Engineers, now IEEE 
IRI Ionospheric Research Instrument, transmitter part of HAARP 
IRINT Infrared intelligence 
IRIS Improved Radio Ionospheric Sounder 
IRL Ireland (country code) 
IRN Iran (country code) 
IRQ (1)Interrupt request (computer hardware) 
IRQ (2)Iraq (country code) 
IRRM Image Recording Request Message 
IRRS Italian Radio Relay Service 
IRS (1)Information Receiving Station (SITOR) 
IRS (2)Internal Revenue Service (US) 
IRS (3)Infernal Revenue Service (U$) 
IRSS Infrared Surveillance System 
IRST Infrared Search and Track 
IS (1)Interval signal 
IS (2)Intermediate Standard, formerly RS 
IS (3)Information System 
IS-136 ANSI-136 multiple access standard 
ISA (1)Industry Standard Architecture (PC-AT bus) 
ISA (2)In-Session Activation (telco) 
ISABPS Integrated Submarine Automated Broadcast Processor System 
ISAM Indexed Sequential Access Method 
ISARC Intelligence, Surveillance, and Reconnaissance Cell 
ISB (1)Independent Sideband 
ISB (2)Intermediate Staging Base 
ISC Initial Scope Command (phase I) 
ISD Inverted Scanning Direction (radiofax) 
ISDB Integrated Services Digital Broadcasting (Japanese digital TV/Radio) 
ISDL ISDN Digital Subscriber Line 
ISDN Integrated services & data network (telco) 
ISEC Information Systems Engineering Command 
ISF International Science Foundation 
ISI Inter-Symbol Interference 
ISM Industrial, Scientific, Medical (RF devices) 
ISMLS Interim Standard Microwave Landing System 
ISO (1)International Organisation for Standardisation 
ISO (2)International Organizations for Standardization 
ISODE ISO Development Environment 
ISP Internet service provider 
ISR In-System Reprogrammable 
ISS (1)Information Sending Station (SITOR) 
ISS (2)International Space Station 
ISSO (1)Information System Security Officer 
ISSO (2)Information Systems Security Organization (US) 
ISTR I Seem To Recall 
IT (1)Information Technology 
IT (2)Information Technology Directorate (FEMA) 
ITA International Telegraph Alphabet 
ITA1 International Telegraph Alphabet #1 (Old cablegrams, obsolete) 
ITA2 International Telegraph Alphabet #2 (Baudot double-shift) 
ITA3 International Telegraph Alphabet #3 (7-bit ARQ) 
ITA4 International Telegraph Alphabet #4 (FM VFT) 
ITER Improved Triple Ejector Rack 
ITFS Instructional Television Fixed Service 
ITO Installation transportation office 
ITS (1)Institute for Telecommunication Sciences 
ITS (2)Intelligent Transportation Systems 
ITU International Telecommunications Union 
ITU-R M.493-6 - Protocol for maritime Digital Selective Calling 
ITU-R ITU Sector for Radiocommunications, old CCIR 
ITU-T International Telecommunications Union - Telecommunication Standardization Sector 
ITU-T ITU Sector for Telecommunications, old CCITT 
ITU-TSS ITU Telecommunications Standards Section, old CCITT 
ITWS Integrated Terminal Weather System 
IUGG International Union of Geodesy and Geophysics 
IUSS Integrated Undersea Surveillance System 
IUWDS International Ursigram and World Days Service 
IVAS Inward Voice Activated Services (telco) 
IVCS Integrated Voice Communication Systems 
IVTT Integrated VERDIN Transmit Terminal 
IW Information Warfare 
IWS Information Warfare Squadron 
IWTS Integrated Terminal Weather System 
IXS Information Exchange System 
j Vector 
J/S Jamming to signal ratio 
J2 Intelligence directorate at a joint headquarters 
J2B Single sideband, suppressed carrier tone teleprinting (emission) 
J3E Single sideband, suppressed carrier AM radiotelephony (emission) 
J4 Logistics directorate at a joint headquarters 
JAA Joint Aviation Authorities (Europe) 
JAFO Just Another F[ine] Observer 
JAG Judge Advocate General 
JALBTCX Joint Airborne Lidar Bathymetry Technical Center of Expertise 
JAN Joint Army/Navy (spec) 
JANA Jamahiriyah News Agency 
JANET Joint Academic NETwork (UK) 
JAR Joint Aviation Requirements (Europe) 
JASORS Joint Advanced Special Operations Radio System 
JATACS Joint Advanced Tactical Command and Control System 
JATCC Joint Air Traffic Control Center 
JAWS Juneau Airport Wind System 
JAWSAT Joint Air Force-Weber State University Satellite 
JCS Joint Chiefs of Staff 
JCSE Joint Communications Support Element 
JDF Japanese Defense Force 
JDISS Joint Deployable Intelligence Support System 
JEDEC Joint Electronic Device Engineering Council 
Jeep Believed from "General Purpose" military vehicle, now a tradename 
JFA Japan Fisheries Association 
JFC Joint force commander 
JFET Junction Field-Effect Transistor 
JIATF-E Joint Interagency Task Force, East (incorporates JTF-4) 
JIATF-S Joint Interagency Task Force, South (inc. JTF-6) 
JIATF-W Joint Interagency Task Force, West (inc. JTF-5) 
JIC Joint Information Center 
JINTACCS Joint Interoperability of Tactical Command and Control Systems 
JIT Just In Time (JAVA Compiler, proprietary to Sun) 
JITC Joint Interoperability Test Command (US) 
JIVE Jamming and Interception Vulnerability Estimator 
JJ (1)Joprep Jiffy (obsolete SAC weather report form) 
JJ (2)Transmission is in Japanese 
JJY Japanese standard frequency & time station [~] 
JMA Japan Meteorological Agency 
JMC (1)Joint movement center 
JMC (2)Jamaica (country code) 
JMPA Joint Military Postal Agency 
JMRO Joint medical regulating office 
JN Japanese Navy 
JOPES Joint Operations Planning and Execution System 
JOPREP Joint Operations Report 
JORN Jindalee Operational Radar Network (Australian OTH-B) 
JORN Jindalee OTH Radar Network 
JOSAC Joint Operational Support Airlift Center 
JOTS Joint Interoperability Targeting System 
JOVIAL Jules' Own Version of the International Algebraic Language, once used by USAF 
JP (1)Joint publication 
JP (2)Jumper (connection) 
JP4 Jet Propulsion #4 (military jet fuel) 
JPATS Joint Primary Aircraft Training System 
JPEG Joint Photographic Experts Group (lossy compression for pictures) 
JPL Jet Propulsion Laboratory, CA (NASA) 
JPNIC Japanese Network Information Center 
JRCC Joint Rescue Coordination Center 
JRTC Joint Readiness Training Center (Ft. Polk, LA) 
JSC Johnson Space Center, TX 
JSC Joint Spectrum Center 
JSF Joint Strike Fighter 
JSMSw Joint Spectrum Management Spectrum for Windows (software) 
JSORS Joint Advanced Special OPS Radio System 
JSTARS Joint Surveillance Target Attack Radar System, aka "Joint STARS," E-8 surveillance aircraft 
JTF Joint Task Force, usually US "War on Drugs" 
JTF-4 Caribbean drug interdiction unit, out of Key West, part of JIATF-E 
JTF-5 Pacific coast drug unit, part of JIATF-W 
JTF-6 South & Central America drug unit, part of JIATF-South 
JTFEX Joint Task Force Exercise 
JTIDS Joint Tactical Information Distribution System 
JTRS Joint Tactical Radio System 
JU JTIDS Unit (net member, like a "PU" in Link-11) 
JUH-MTF Joint user handbook for message text format 
JWICS Joint Worldwide Intelligence Communications System 
K Index Logarithmic, 3-hourly geomagnetic activity reading 
K (1)1024 (decimal) of anything (loosely from hexadecimal) 
K (2)CW prosign: "Go Ahead," technically an "Invitation To Transmit" 
k A thousand of anything, in decimal (short for kilo) 
k/c Kilocycles 
K/cs Kilocycles per second = kiloHertz 
KA9Q Packet radio protocol, from callsign of its inventor [~] 
KAM Kantronics All-Mode (packet/digital controller) 
KAWN Identifier attached to AWN weather products, as relayed by several HF stations 
KB Keyboard 
kB Kilobit, kilobaud 
kb/s kilobits per second 
KBD Keyboard 
kBd Kilobaud 
Kbps Kilobits per second 
KBS Korea Broadcasting System 
kc Kilocycles per second, now kHertz 
KCAS Knots Calibrated Air Speed 
KCNA Korean Central News Agency 
kcs Kilocycles per second, now kHertz 
KDU Keypad-Display Unit 
KFOR Kosovo Forces 
KGB Komitet Gossudarstwennoy Besopasnostij (transliterated from Russian by Klingenfuss), old USSR comint, replaced by FAPSI 
KH Keyhole, optical recon satellite, KH-12 resembles Hubble 
kHz KiloHertz 
KIPM Illuminati Primum Materium (Pirate) 
KISS Keep it simple, stupid (packet radio mode/engineering golden rule) 
km kilometer 
kMc kilo-Megacycle, now GigaHertz 
knot Nautical mile/hour [~] 
KNRM Koninklijke Nederlandse Redding Maatschappij (Dutch SAR org.) 
KOR (South) Korea (country code) 
Kp Planetary K index 
kph kilometer per hour 
KRE (North) Korea (country code) 
KSC Kennedy Space Center, Cape Canaveral, FL 
KSCPAO Kennedy Space Center Public Affairs Office (NASA) 
ksh Korn shell (Unix) 
KSR Keyboard Send-Receive 
kt knot (nautical mile per hour) 
KT knots 
KTS knots 
Ku-band 12-18 GHz microwave band 
kV Kilovolt 
KVA KiloVolt-Amp(s); can <> kW in highly reactive circuit 
kW Kilowatt 
L Inductance (in Henrys) 
L left (with reference to runway designation) 
L2TP Layer 2 Tunneling Protocol 
LA Low altitude 
Ladar Laser Radar 
LAHSO Landing And Hold Short Operations 
LAN Local Area Network 
LANL Los Alamos (NM) National Laboratory 
LANTAREA USCG Atlantic Area 
LANTIRN Low Altitude Navigation and Targeting Infra Red for Night 
LAO Laos (country code) 
LAPD (1)Link Access Procedure D-Channel 
LAPD (2)Los Angeles Police Department 
LAPM Link access protocol for modems 
LASER Light Amplification by Stimulated Emission of Radiation 
LAST last observation before a break in coverage at a manual station 
LAU Launcher Adapter Unit 
LBA Logical Block Addressing (Disk access) 
LBAR Limited area BARotropic (NCEP weather model) 
LBN Lebanon (country code) 
LBR Liberia (country code) 
LBY Lybia (country code) 
LC Limited Coastal (service) 
LCA St. Lucia (country code) 
LCAC Landing Craft, Air-Cushioned (large hovercraft) 
LCC Launch Control Center 
LCD Liquid Crystal Display 
LCMP Atlantic Composite Broadcast 
LCP Link Control Protocol (PPP) 
LCS Limited Coastal Station 
LCU Landing Craft, Utility (US Army) 
LDAP Lightweight Directory Access Protocol 
LDF Lightweight digital facsimile 
LDOC Long Distance Operational Control (civil aviation) 
LDP Landing Decision Point 
LDR (1)Low Data Rate 
LDR (2)Loader 
LDTWA Long Dual Trailing Wire Antenna (TACAMO) 
LEARN Law Enforcement Amateur Radio Network 
LEASAT Leased Satellite (US military comm) 
LED Light Emitting Diode 
LEO Low Earth Orbit ("Little LEO" = a data satellite) 
LES Land Earth Station 
LF (1)Low Frequency (30-300 kHz) 
LF (2)Linefeed 
LFO Low frequency oscillator 
LG Logistics Group 
LGTR Laser Guided Training Round 
LHCP Left-hand circular polarization 
LIAR Liar Imitates Apply Recursively (recursive) 
Lidar Light Detection & Ranging (light "radar") 
LIE Liechtenstein (country code) 
LIM (1)Lotus/Intel/Microsoft, original spec for PC extended memory 
LIM (2)Line interface module 
LINCOMPREX Link Compression and Expansion, an ACSB system 
Linux "Linus' Unix," open source shareware version of Unix 
LIRL Low Intensity Runway Lights 
LL Landline, "Lima Lima" 
LLC (1)Logical Link Control 
LLC (2)Limited Liability Corporation (US) 
LLCC Low Level Cloud Center (wx obs) 
LLNL Lawrence Livermore National Laboratory 
LLP Limited Liability Partnership (US) 
LLWAS Low Level Wind Shear Alert System 
LMAO Laughing My A-- Off (Internet) 
LMCC Land Mobile Communications Council 
LNB Low Noise amplifier/Block downconverter 
LNBF Low Noise amplifier/Block downconverter Feedhorn 
ln Natural logarithm 
LNP Local Number Portability (cell phones) 
LO Local oscillator (of a receiver) 
LOC (1)lines of communication 
LOC (2)location 
log Common logarithm 
LOGCAP Logistics Civil Augmentation Program 
LOGPAC Logistics package 
LOI Low Opportunity of Intercept 
LOJACK Vehicle locator beacon activated & DF'd by police 
LOL Laughing Out Loud (internet) 
LORAC Long Range Accuracy (NASA booster recovery) 
LORAN Long Range Navigation 
LORAN-A Discontinued 160m Loran system 
LORAN-C 100 kHz Loran system 
LORAN-D Military Loran system 
LOS (1)Loss Of Signal 
LOS (2)Line of sight 
LOTS logistics-over-the-shore 
LOWFER Low-Frequency Experimental Radio (~164-190 kHz) 
LP (1)Long Playing (old records) 
LP (2)Low pass (filter circuit) 
LP (3)Linking Protection (US mil ALE security) 
LP (4)Log Periodic (antenna) 
LPB Logistics preparation of the battlefield 
LPD Line Printer Daemon 
LPDA Log Periodic Dipole Array 
LPDU HDFL: Link Protocol Data Unit 
LPFM Low-Power FM (broadcasting) 
LPI Low Probability of Intercept 
LPM Lines per minute 
LPR Line Printer 
LPRS Low-Power Radio Service (FCC) 
LPT Logistics preparation of the theater 
LPTV Low-Power TV (broadcasting) 
LPVA Log Periodic V Array 
LQA Link Quality Analysis (databursts heard from ALE radios) 
LR Last Received (message) 
LRA Landing Rights Airport 
LRC (1)Longitudinal Redundancy Check (computing) 
LRC (2)Logistics and Readiness Center 
LRCOC Long Range Company Operational Control 
LS Last Sent (message) 
LSASS Local Security Authority Subsystem Service (Windoze) 
LSB (1)Lower Sideband 
LSB (2)Linux Standard Block 
LSB (3)Least Significant Bit/Byte 
LSDIS Light and Special Division Interim Sensor (US Army) 
LSE Logistics support element 
LSI (1)Large scale integration (of chips) 
LSI (2)Locomotive System Integration 
LST (1)Landing ship, tank 
LST (2)Local Standard Time 
LSV Logistic Support Vessel (US Army) 
LTG lightning 
LTR Letter(s) 
LTRS Letters case (Baudot lower case) 
LUF Lowest Usable Frequency (varies with path) 
LUT Local User Terminal 
LUU Parachute Flare 
LWR lower 
LZW Lempel-Ziv-Welch, lossless compression algorithm for data 
M (1)Mega, meg, a million of anything, or 1,048,576 bytes (hex) 
M (2)minus, less than 
M (3)Below zero C 
M (4)Statute Mile 
m Meter (39.37 inches) 
M/S (1)Motor Ship (also MS, M.S.) 
M/S (2)Mile per second 
m/s Meter per second 
M/V Motor Vessel (also m/v) 
m/v Motor Vessel (also MV) 
M1FC Model 1 Full Capacity (Air traffic control) 
mA milliamperes 
MAC (1)Military Airlift Command, now AMC 
MAC (2)Medium Access Control (computer networks) 
Mac Macintosh (computer) 
MACOM Major command 
MacTCP TCP/IP package for Macintosh 
MAFFS Modular Airborne Fire Fighting System (tank for C-130) 
MAFOR Maritime weather forecast 
MAGIS Marine Air-Ground Intelligence System 
mAh miliamp-hour(s) 
MAIT Major Accident Investigation Team (CHP) 
MAN Metropolitan Area Network, halfway between a LAN and a WAN 
MANPAD Man-Portable Air Defense 
MAP Maghreb Arabe Presse 
MAPI Mail/Messaging Applications Programming Interface 
MAPS Mail Abuse Prevention System (Internet) 
MARAD MARitime ADministration [~] 
MARC MAchine Readable Catalog 
MARCEMP Manual Relay Center Modernization Program (USN) 
MARO Maritime Air Radio Organization 
MARS (1)Military Auxiliary Radio System (US) 
MARS (2)Maritime (mobile) Access & Retrieval System (ITU ship lookup) 
MARSA Military Assumes Responsibility for Separation of Aircraft 
MARSEC Marianas Sector (US Coast Guard) [~] 
MASER Microwave Amplification by Stimulated Emission of Radiation 
MASH Mobile Army Surgical Hospital, may be obsolete 
MASM Macro-Assembler (computer code) 
MATIC Mobility Assessment Test and Integration Center 
MATS Military Air Transportation Service, became MAC, now AMC 
MAU Media Attachment Unit, a network transceiver 
MAVICA Magnetic Video Camera 
MAYDAY Prosign: Distress traffic follows; repeated 3 times [~] 
MB Megabyte 
mb millibar 
MBCS (1)Multi Byte Character Set (Unicode) 
MBCS (2)Magnetic Bridge Current Sensor 
MBDL Missile Battery Data Link 
MBKS Multi-Button Key Set (telco) 
MBO Mailbox 
MBONE Multicast Backbone 
Mbps Megabytes per second 
MBR Master Boot Record ("boot sector") 
MCA Movement control agency 
MCC Master Control Center 
MCC Movement control center 
MCFB Multi-Channel Fleet Broadcast 
MCM Mine Countermeasures 
MCP (1)Mobile communications package 
MCP (2)Multimode Communications Processor (packet) 
MCP (3)Male chauvinist pig 
MCS Mission Communications System 
MCS/P Maneuver Control System/Phoenix (US Army) 
MCVFT Multichannel Voice Frequency Telegraph (multiplex RTTY) 
MD5 Message-Digest, algorithm 5 (crypto, 128-bit) 
MDR Medium Data Rate 
MDS Multipoint Distribution Service 
MDT (1)Mobile Data Terminal (usually police) 
MDT (2)Mountain Daylight Time, US zone includes Rockies 
med medical 
MEDAFS Mine Warfare Environmental Data Analysis and Fusion System 
MEDCOM Medical command 
MEDFER Medium-frequency Experimental Radio (low power ~510-1710 kHz) 
MEDICAL Voice prosign attached to c/s of vessel with emergency medical supplies or patients, pronounced MAY-DEE-CAL 
MEDICO Emergency Medical Communications 
MEDLOG Medical logistics 
MEL Maximum Elevation (of a spacecraft) 
MEMA Massachusetts Emergency Management Agency 
MEOW (1)Maximum Envelope of Water 
MEOW (2)Maximum Envelope of Winds 
MER-# Mars Exploration Rover # (NASA) 
MERCAST MERchant ship broadCAST 
MEROD Message Entry and Read Out Device (Thales-Racal, see RAC-ARQ) 
MERS Mobile Emergency Response Support (FEMA) 
Messenger Mercury Surface, Space Environment, Geochemistry and Ranging 
Met Office Weather office at a base 
MET Meterological 
METAR Meteorological observation code for routine aviation 
METAREA Meteorological Area, same as a NAVAREA (see WMO) 
METARS Plural of METAR 
Meteo Meteorological 
METOC Meteorological and Oceanographic Centre (Halifax, NS) 
Metro Meteorological office 
METSAT Meterological Satellite 
MF (1)Medium Frequency (300-3000 kHz) 
MF (2)Multifrequency 
mf Microfarad 
MFA Ministry of Foreign Affairs 
MFD Modulated Fractional Division 
MFM Modified Frequency Modulation (Miller Coding) 
MFSK Multiple Frequency Shift Keying 
mgt management 
mH Millihenry 
MHD Magnetohydrodynamics; behavior of plasmas in magnetic fields, such as the ionosphere and sunspots 
MHE materials-handling equipment 
MHFCS Australian Modernised HF Communication System 
MHS Message Handling System 
MHz MegaHertz 
MI (1)Military intelligence 
MI (2)shallow 
mi mile (1.6 km) 
MI5 Directorate of Military Intelligence, group 5 (UK domestic) 
MI6 Directorate of Military Intelligence, group 6 (UK foreign, aka SIS) 
MIB Management Information Base 
MICR Magnetic Ink Character Recognition (as used by banks) 
MICS Medical Implant Communications Service 
MID (1)Middle East (MWARA) 
MID (2)Maritime Identification Digits, country code prepended to MMSI 
MIDI Music Industry Digital Interface 
MIDS Multifunctional Information Distribution System 
MIFG Shallow Fog 
MIJI Meaconing, Intrusion, Jamming & Interference ("Jammer writeup") 
Mil (1) Military 
Mil (2) Milliampere 
MIL-188-110A NATO standard for single-tone modems 
MIL-188-141A NATO standard for ALE controllers 
MIME Multipurpose Internet Mail Extensions, allows attachment of binaries to ASCII text letters 
MIMS Medical Information Management System 
min Minute 
MIN Mobile Identification Number 
MINIMUF Miniature Maximum Usable Frequency calculator, classic BASIC MUF prediction algorithm 
MINREX Ministerio de las Relaciones Exteriores (Cuban news agency) 
MIR Not an acronym; transliteration of Russian for "Peace" 
MIREX Mir Experiment, amateur robot packet station on Mir 
MIRL Medium Intensity Runway Lights 
MIS Management Information Systems 
MISDN Mobile ISDN 
MISR Multi-angle Imaging SpectroRadiometer (Terra satellite) 
MIT Massachussetts Institute of Technology 
M-JPEG JPEG used for moving pictures (cf JPEG, MPEG) 
mkr Marker 
ML Machine language, how computers store instructions 
MLB (1)Motor Lifeboat 
MLB (2)Magnetic Longwire Balun 
MLM Marine Location Marker 
MLS Microwave Landing System 
MLSE Maximum Likelihood Sequence Estimator 
MLSO Mauna Loa Solar Observatory 
MLT Magnetic Local Time 
MM Maritime mobile 
mm Millimeter 
MMC (1)materiel management center 
MMC (2)Microsoft Management Console 
mmf micro-microfarad, changed to picofarad 
MMS Maritime Mobile Service 
MMSI Maritime Mobile Service Identity (code for DSC) 
MMX Multimedia extensions (microprocessor architecture) 
MNCS Master Net Control Station 
MNP Modem Network Protocol 
MOA Military Operation Area 
MOAB Massive Ordnance, Air Blast 
Mob Mobile 
MOC (1)Mission Operation Center 
MOC (2)Ministry Of Commerce (Canada) 
MOC MERS Operations Center (FEMA nested acronym) 
MOCA Minimum Obstruction Clearance Altitude 
MoD Ministry of Defence (UK) 
MOD (1)Ministry of Defense 
MOD (2)Mobile Offshore Drilling 
Mod Modification (to radio) [~] 
Mode A SITOR-A (ARQ) 
Mode B SITOR-B (FEC) 
Modem Modulator/Demodulator 
MODIS Moderate Resolution Imaging Spectroradiometer (Terra satellite) 
MODU Mobile Offshore Drilling Update 
MOI Ministry Of Information 
MOOTW Military operations other than war 
MOP (1)Measure Of Performance 
MOP (2)Ministry Of Petroleum 
MOPP mission-oriented protection posture (0-4, 4 being full suit) 
MOS (1)Metallic Oxide Silicon 
MOS (2)Mitoudt Sound, shooting film with a silent camera 
MOSAIC Multifunctional On-the-move Secure Adaptive Integrated Communications 
MOSFET MOS Field Effect Transistor 
MOSS MIME Object Security Services 
MOTD Message Of The Day 
MOTIS Message Orientated Text Interchange Service, ISO version of MHS 
MOV moved/moving/movement 
MOX Manually Operated Switching 
MOZ (1)Mozambique (country code) 
MOZ (2)Mozilla (computer browser) 
MP (1)Military Police (US) 
MP (2)Member of Parliament (UK) 
MP (3)Multiprocessor (computer h/w) 
MP Magnetopause 
MP2 MPEG-1 Level 2, replaced by MP4 
MP3 MPEG-1 Level 3, CD-quality compression scheme 
MP4 MPEG-1 Level 4, audio/video compressor 
MPDU HFDL: Media access Protocol Data Unit 
MPEG Motion Picture Expert Group, lossy compression for video 
MPG (1)File extension: MPEG video 
MPG (2)Miles Per Gallon 
mph mile per hour 
MPSA Military Postal Service Agency 
MPSAP Mobile Public Safery Answering Point 
MPX Multiplex 
MR Magnetoresistive 
MRB Marine Radio Beacon 
MRC (1)Mobile Radio Communications 
MRC (2)Morocco (country code) 
MRCC Maritime Rescue Coordination Center 
MRE Meal, Ready-to-Eat 
MRF Medium Range Forecast (NCEP) 
MRO medical regulating office 
MRS Mountain Radio Service 
MRSC Maritime Rescue Sub-Center 
MRS MPA Medium Range Surveillance Maritime Patrol Aircraft 
MRT (1)Mountain Rescue Team 
MRT (2)Mauretania 
MRU Most Recently Used 
MS Master Station 
ms millisecond 
mS millisiemen 
MS (1)Motor Ship 
MS (2)Meteor Scatter 
MS-188 MIL-STD-188, Military telecom standards 
MSB (1)Most Significant Bit/Byte 
MSB (2)Main Support Battalion 
MSC Military Seaflift Command (US) 
MSE (1)Mobile Subscriber Equipment 
MSE (2)Mean Square Error 
MSF (1)English standard frequency & time station 
MSF (2)Medicins Sans Frontiers (Doctors Without Borders) 
MSFC NASA Marshall Space Flight Center 
msg Message 
MSI (1)Maritime Safety Information 
MSI (2)Marine Safety Information 
MSIS Mass Spectrometer Incoherent Scatter (research) 
MSK Minimum Shift Keying 
MSR (1)main supply route 
MSR (2)Mobile Sea Range 
MSS Mobile Satellite Service 
MST (1)Mountain (US) Standard Time, zone includes Rockies 
MST (2)Maintenance support team 
MT (1)Monitoring Times (**the bible**) 
MT (2)mountain(s) 
MT (3)Mitigation Directorate (FEMA) 
MTA (1)Message Transfer Agent 
MTA (2)Metropolitan Transit Authority 
MTADS Multi-sensor Towed Array Detection System 
MTBF Mean Time Before Failure 
MTF medical treatment facility 
MTI Moving Target Indicator 
MTMC Military Traffic Management Command 
mtr Meter, either distance unit or measuring device 
MTTR Mean Time To Repair 
MTU Maximum Transmit Unit (TCP/IP packet length) 
MUF Maximum Usable Frequency (varies with path) 
MULTICS Multiplexed Information and Computing Service; Unix precursor 
Mung (1) Verb: to Mash Until No Good 
Mung (2) Verb: to Mung Until No Good (recursive acronym) 
MURS Multi-Use Radio Service 
MUX Multiplex, multiplexer 
mV Millivolt 
MV Motor Vessel 
MVS Multiple Virtual Storage (large IBM computers) 
MW (1)Medium Wave (typically 530-1710 kHz) 
MW (2)MegaWatt 
mW MilliWatt 
MWARA Major World Air Route Area 
MWP Meteorologist Weather Processor 
MWR Morale, welfare, and recreation 
MX Mail Exchange Record 
mx Music 
MYA Myanmar (Burma;country code) 
MYM My Mailbox (packet) 
MYP Personal Mailbox (packet) 
N No Change 
N north 
N/A not applicable 
N0N Unmodulated, steady carrier, old "A0" 
NA (1)North America 
NA (2)Not applicable, N/A 
NA Not authorized 
NAAS Naval Auxiliary Air Station 
NAB (1)National Assn of Broadcasters 
NAB (2)Naval Amphibious Base, USN, Coronado, CA (SEALs train there) 
NABA North American Broadcasters Assn. 
NABER National Association of Business/Emergency Radio 
NACES Naval Aircrew Common Escape System 
NAD 83 North American Datum of 1983 
NADC Naval Air Development Center 
NADEP Naval Air Depot 
NADGE NATO Air Defence Ground Environment 
NAEC Naval Air Engineering Center 
NAF Naval Air Facility (US) 
NAFB National Assn of Farm Broadcasters 
NAK Negative Acknowledgment (error in received data, ASCII 21d) 
NALF Naval Auxiliary Landing Field 
NALO Naval Air Logistics Office 
NAM Number Assignment Module (Cellular) 
NANP North American Numbering Plan (telco) 
NAOC National Airborne Operations Center, aka Nightwatch, old NEACP 
NARTE Natl Assn of Radio & Telecommunications Engineers 
NARTEL North Atlantic Radiotelephone 
NAS (1)Naval Air Station 
NAS (2)National Academy of Sciences (US) 
NAS (3)National Airspace System 
NAS (4)Network Access Server 
NASA (1)National Aeronautics and Space Administration 
NASA (2)National Acronym Slinging Agency 
NASTD National Association of State Telecommunications Directors 
NAT (1)North Atlantic (MWARA) 
NAT (2)Network Address Translation 
NATC Naval Air Test Center 
NATO North Atlantic Treaty Organization 
NATOPS Naval Air Training and Operating Procedures Standardization 
NAV Navigation 
NAV/COMM Airplane Navigation/Communication radio 
NAVAID Navigational aid 
NAVAIR Naval Air Systems Command 
NAVAREA Navigational Area (IMO/IHO) 
NAVCEN USCG Navigation Center, VA 
NAVCOMMAREA Naval Communication Area 
NAVCOMPARS Naval Communications Processing and Routing System 
NAVCOMMSTA Naval Communications Station 
NAVCOMTELCOM Naval Computer and Telecommunications Command 
NAVMARCORMARS Navy/Marine Corps Military Affiliate Radio Service (US) 
NAVMTO Navy Material Transportation Office 
NAVRADTRANSFAC Navy Radio Transmitter Facility 
NAVSAT NAVigation SATellite 
NAVTEX Navigational Telex, Navigational Text (518 kHz SITOR-B) 
NAWAS National Warning System 
NAWC Naval Air Warfare Center 
NAWCAD Naval Air Warfare Center Aircraft Division 
NAWC-WPN Naval Air Warfare Center 
NAWS (1)Naval Air Weapons Station 
NAWS (2)Old group call: Notice to Allied Warships 
NB (1)Narrowband 
NB (2)Noise blanker 
NBC (1)Nuclear, Biological, Chemical (warfare) 
NBC (2)National Broadcasting Company 
NBDP Narrowband direct printing (RTTY) 
NBDPT Narrowband direct printing telegraphy 
NBF NetBIOS Frames 
NBFM Narrowband frequency modulation 
NBR Narrowband Receiver 
NBS National Bureau of Standards, now NIST 
NBSV Narrowband Secure Voice 
NBSVS Narrowband Secure Voice System 
NC (1)No Connection 
NC (2)Normally Closed 
NC3A NATO Consultation, Command and Control Agency (Nested acronym!) 
NCA (1)North Central Asia (MWARA) 
NCA (2)National Command Authorities, US nuclear "button" 
NCAR National Center for Atmospheric Research, CO 
NCC National Coordinating Center for Telecommunications (US NCS) 
NCCOSC Naval Command, Control and Ocean Surveillance Center 
NCCS Navy Command and Control System 
NCDC National Climatic Data Center 
NCEM National Coordinating Council for Emergency Management, now IAEM 
NCEP National Center for Environmental Prediction 
NCFSK Non-Coherent Frequency Shift Keying 
NCG Nicaragua (country code) 
NCIC National Crime Information Center, US database of police records 
NCIS Naval Criminal Investigative Service 
NCO Non-Commissioned Officer 
NCPi Netware Core Protocol 
NCR (1)National Capital Region (US) 
NCR (2)National Cash Register 
NCS (1)National Communications System, US government 
NCS (2)Net Control Station 
NCS (3)Naval Communications Station 
NCS (4)Network Coordinating Station 
NCSA National Centre for Supercomputing Applications, developed Mosaic web browser, which became Netscape (Mozilla) 
NCTAMS Naval Computer and Telecommunications Area Master Station 
NCTS Naval Computer and Telecommunications System 
NCTSI Navy Center for Tactical Systems Interoperability (US) 
NCWF National Convective Weather Forecast 
ND Nondirectional 
NDB Nondirectional beacon 
NDIS Network Driver Interface Specification 
NDMS National Disaster Medical System 
NDRS National Distress and Response System 
NDRSMP National Distress and Response System Modernization Project 
NDS NUDET Detection System, see NUDET 
NE Northeast 
NEACP National Emergency Airborne Command Post, "kneecap," now NAOC 
NECC National Emergency Coordination Center (FEMA) 
NECN National Emergency Coordination Network 
NERC North American Electric Reliability Council (bulk power delivery) 
NERK Old CW group call, obsolete 
NESDIS National Environmental Satellite, Data and Information Service 
NESP Navy EHF Satellite Program 
NEST Nuclear Emergency Search Team ("Flynest") 
NET/ROM Network packet radio protocol 
NetBEUI NetBIOS Extended User Interface 
NetBIOS Network Basic Input/Output System 
NEXRAD Next generation of (weather) Radar 
NFCB National Federation of Community Broadcasters (US) 
NFCC National Frequency Coordinators' Council 
NFO Naval Flight Officer (same as RIO) 
NFR Navy Fleet Relay (USN secure satcom) 
NFS Network File System 
NFWS Navy Fighter Weapons School 
NGA National Geospatial-Intelligence Agency (ex-NIMA) 
NGLT Next Generation Launch Technology 
NGO (1)Nongovernmental organization 
NGO (2)Near-Geosynchronous Orbit 
NGO (3)Naval Gunnery Officer 
NHC National Hurricane Center, i.e. TPC 
NHK Nihon Hoso Kyokai , Japanese public broadcast co. 
NIC (1)Network Interface Card 
NIC (2)Network Information Center 
NiCad Nickel Cadmium (battery) 
NiCd Nickel Cadmium (battery) 
NICP National inventory control point 
NIEX No-Notice Interoperability Exercise (NATO) 
NIFC National Interagency Fire Center (US forest fire resources) 
NIFTP Network Independent File Transfer Protocol 
NIL CW prosign: "No traffic" or "I copy nothing" 
NIMA National Imagery and Mapping Agency (now NGA) 
NIMBY Not In My Back Yard (place people want radio towers) 
NiMH Nickel-metal hydride (battery) 
NiMh Nickel-Metal-Hydride (battery) 
NIMS Naval Ionospheric Measuring System (UK) 
Niner Number nine, to distinguish from five [~] 
NIPRNET Non-Classified Internet Protocol Router Network (military's own Internet, with SIPRNET) 
NIS Network Information System 
N-ISDN Narrow Band-Integrated Services Digital Network 
N-ISDN Narrowband ISDN 
NISO National Information Standards Organisation (US) 
NISP Networked Information Services Project (UK) 
NISS National Information on Software and Services (UK) 
NIST National Institute of Standards & Technology (old NBS) 
NLM Netware Loadable Module (extension of Novell Netware) 
NLSP Netware Link Services Protocol 
Nm (1)Nautical Mile(s) 
Nm (2)Nanometer 
NM Nautical Mile(s) 
nm Nautical Mile(s); about 1.24 statute miles(1.85 km) 
NMA US Coast Guard COMMSTA, Miami, now controlled from CAMSLANT 
NMC (1)National Meteorological Center 
NMC (2)Call of US Coast Guard CAMSPAC Pt Reyes, CA 
NMC (3)Naval Missile Center 
NMEA National Marine Electronics Assn 
NMF US Coast Guard COMMSTA, Boston, will be ctld from CAMSLANT 
NMG US Coast Guard COMMSTA, New Orleans, remote from CAMSLANT 
NMN US Coast Guard CAMSLANT Chesapeake, VA 
NMO US Coast Guard COMMSTA, Honolulu 
NNCC National Network Control Center (FAA) 
NNE North-northeast 
nnnn RTTY/Telex ending characters 
NNR National Nature Reserve 
NNTP Network News Transfer Protocol (USENET) 
NNW North-northwest 
NO Normally Open 
NOAA National Oceanic & Atmospheric Administration 
NOC (1)Network Operation Center 
NOC (2)Non-Official Cover (now "OGA") 
NOE Nap-Of-the-Earth (low altitude attack) 
NOGAPS Navy Operational Global Atmospherics Prediction System 
NOI Notice Of Inquiry (FCC rulemaking) 
NOIWON National Operations Intelligence Watch Officers Net 
NOJ US Coast Guard COMMSTA, Kodiak 
NOMTS Naval Ordnance Missile Test Center 
NORAD North American Aerospace Defense Command 
NORAPS Navy Operational Regional Atmospherics Prediction System 
NORDO (1)No Radio 
NORDO (2)Aircraft has no radio (uses visual signals to tower) 
NORLANT North Atlantic 
norm normal 
NOS (1)Amateur version of TCP/IP (Internet protocols) 
NOS (2)National Ocean Service 
NOS (3)Network Operating System 
NOS (4)New, Old-Stock (wine or vacuum tubes) 
NOSC Naval Ocean Systems Center, San Diego, CA, now NCCOSC 
NOSIG No Significent Weather 
NOSPECI no SPECI reports are taken at the station 
NOTAM Notice to Airmen 
NP North Pacific (MWARA) 
NPA Notice of Proposed Amendment 
NPN Negative/Positive/Negative; transistor type 
NPR National Public Radio (US) 
NPRM Notice of Proposed Rule Making (FCC) 
NPS National Park Service (US) 
NPSC National Process Serving Center (FEMA) 
NPSTC National Public Safety Telecommunications Council 
NRaD Naval Research and Development (US) 
NRAO National Radio Astronomy Observatory 
NRC (1)National Radio Club 
NRC (2)Nuclear Regulatory Commission (US) 
NREN National Research and Education Network, faster Internet successor for research sites 
NRI Net radio interface 
NRK Norsk Rikskringkasting (Denmark broadcast co.) 
NRL Naval Research Laboratory (US) 
NRN National Radio News (Australia) 
NRO National Reconnaissance Office (operates US spy satellites) 
NRS (1)Naval Radio Section (Canforce) 
NRS (2)Nordic Radio Society 
NRT Navigation Response Team 
NRTF Naval Radio Transmitting Facility (US) 
NRV US Coast Guard COMMSTA, Guam, controlled from CAMSPAC 
NRWATS Naval Rotary Wing Aircraft Test Squadron 
NRZ Nonreturn to Zero 
NRZL Return To Zero Level 
NRZM Nonreturn To Zero Mark 
NRZS Nonreturn To Zero Space 
NS Node switch 
NS/EP National Security/ Emergency Preparedness 
NSA (1)National Security Agency (US intercept and crypto) 
NSA (2)No Such Agency (NSA used to "not exist") 
NSA (3)Never Say Anything (NSA secrecy policy) 
NSAP Network Service Address Point 
NSAWC Naval Strike and Air Weapons Center (replaces "Top Gun") 
NSAWC Navy Strike Aircraft Weapons Center 
NSE National Support Element 
NSF National Science Foundation (US) 
NSFNET National Science Foundation Network, old Internet backbone 
NSK Narrowband shift keying 
NSS Navigation Safety System 
NSTAC National Security Telecommunications Advisory Committee (US) 
NSU Network Server Unit 
nT Nanotesla (unit of magnetic flux=1nWeber/m) 
NT Not Tested 
NTA (1)National Telecommunications Alliance (NCS) 
NTA (2)National telecom administration (ITU member bodies) 
NTC National Teleregistration Center (FEMA) 
NTCC Naval TeleCommunications Center 
NTCN National Telecommunication Coordination Network 
NTIA National Telecommunications and Information Administration 
NTM Notice to Mariners 
NTMS National Telecommunications Management Structure (national emergency plan) 
NTN NATO Track Number 
NTS (1)National Traffic System, amateur message network 
NTS (2)Naval Telecommunications System 
NTSC (1)National Television Standards Committee (US TV standard) 
NTSC (2)Never The Same Color (result of using above) 
NTT Nippon Telegraph and Telephone (Japanese "FCC") 
NUC Nuclear 
NUCINT Nuclear Intelligence 
NUCO Numerical Code (US Navy) 
NUDET Nuclear detonation 
NUKO Old group call: To All Ships Receiving MERCAST 
NUL Nothing (ASCII 0000) 
NVG Night-Vision Goggles 
NVIC Navigation & Vessel Inspection Circular 
NVIS Near Vertical Incidence Skywave 
NVOAD National Voluntary Organizations Active in Disaster 
NVRAM Nonvolatile Random Access Memory 
NW (1)CW brevity code: "Now," or "New" 
NW (2)Northwest 
NWC Naval Weapons Center 
NWCG National Wildfire Coordination Group 
NWEF Naval Weapons Evaluation Facility 
NWR NOAA Weather Radio 
NWS (1)National Weather Service (US) 
NWS (2)Naval Weapons Station 
NWSFO National Weather Service Forecsting Office 
NWSOP National Winter Storm Operation Plan 
nx News 
NYSEMO New York State Emergency Management Office 
O&O Owned & Operated (by broadcast network) 
o/l Online 
O/R Address Originator/Recipient Address 
O/R On request 
O/S Out of service 
OARNET Ohio Academic Resources Network 
OASD/C3I Office of the Assistant Secretary of Defense for command, control, communications and intelligence 
OASIS Operational and Supportability Implementation System (FAA) 
OBC On-board computer 
OBS Ship weather report in standard form 
OCA Oceanic Control Area 
OCC Operations Control Center (Centre) 
OCD (1)Office of Civilian Defense, obsolete 
OCD (2)Operations Control Division 
OCNL occasional 
OCONUS Outside Continental United States 
OCOT Office of the Chief of Transportation (US Army) 
OCR (1)Optical Character Recognition 
OCR (2)Optically Coupled Regenerative 
OCS Office of Coast Survey 
OD (1)Officer of the Day 
OD (2)Overdose 
OD (3)Outside Diameter 
ODBC Open DataBase Connectivity (Microsoft) 
ODMA Orthogonal Domain Multiple Access 
ODMP Orbiter Maintenance Down Period (NASA) 
OE Operating Expense 
OEI One Engine Inoperative 
OEM Original Equipment Manufacturer 
OFCM Office of the Federal Coordinator for Meteorology 
OFDM Orthogonal Frequency Division Multiplex 
OFP Operational Flight Program 
OG Operations Group 
OGA Other Governmental Agencies (formerly "NOC") 
OHD overhead 
OIC Officer In Charge 
OIS Organization for Internet Security 
OLAC Open Language Archives Community 
OLAP On-Line Analytical Processing 
OLF Outlying Landing Field (US Navy) 
OLTP On-Line Transaction Processing (IBM) 
OLX OLE Custom Control (MS made it up... i didn't) 
OM Male voice ("Old Man") 
OMEGA Optimized Method for Estimated Guidance Accuracy (VLF Navigation) 
OMF (Weather) Observation Markup Format 
OMS ("ohms") Orbital Maneuvering System (NASA) 
OO Official Observer (Amateur) 
OOB (1)Out of band 
OOB (2)Out Of Bounds (classic Internet hack) 
OOC Official Observer Coordinator (Amateur) 
OOK On-off keying 
OOOI Out, Off, On, In (ACARS time reporting) 
OOP Object-Oriented Programming 
OOW Operations Other than War 
OP Observation Post 
op Operation 
OPAL Orbiting Picosat Automatic Launcher 
OPBAT Operations, Bahamas and Turks (see JTF) 
OPC (1)Ocean Prediction Center, Camp Springs, MD 
OPC (2)Operations Center 
OPCEN Operations Center 
OPCODE Operations code 
OPCON Operational control 
OPF Orbiter Processing Facility (NASA) 
OPLAN Operations plan 
OPORD Operation order 
OPSEC Operation Security 
OQPSK Offset Quadrature Phase Shift Keying 
OR Offroute (unscheduled flights, usually military) 
ORACLE Oak Ridge Automated Computer and Logical Engine 
ORBS Open Relay Behaviour-modification System (anti-email-spam) 
ORF Oesterreichischer Rundfunk (Austrian broadcasting co.) 
ORFM Office of Radio Frequency Management 
org organization (Internet) 
OS (1)Operating system (code that runs a computer) 
OS (2)Operations Support 
OS Operations Specialist (combines older USCG RD and TC) 
OS/2 Operating System 2, proprietary IBM op-system for PS/2 
OS/2 Operating System II (IBM) 
OSC (1)Operations Systems Center, USCG, VA 
OSC (2)On-Scene Coordinator 
OSC (3)Oscillator [~] 
OSCAR Orbiting Satellite Carrying Amateur Radio 
OSCE Organization for Security and Cooperation in Europe 
OSCR Ocean Surface Current Radar 
OSEI Operational Significant Event Imagery (NOAA) 
OSI Open Systems Interconnection (coincidentally, OSI is by ISO) 
OSIR ISO's famous 7-layer "OSI Reference Model" for packet 
OSIRM ISO's famous 7-layer "OSI Reference Model" for packet 
OSPF Open Shortest Path First 
OSS Office of Special Services, WWII 
OSTP Office of Science and Technology Policy (US Government) 
OSWER Office of Solid Waste and Emergency Response 
OTAN NATO in French 
OTAR Over-The-Air Rekeying (crypto) 
OTASP Over-the-Air Service Provisioning (telco) 
OTCIXS Officer in Tactical Command Information Exchange System 
OTHB Over The Horizon Backscatter radar 
OTHR Over the horizon radar 
OUI Organizationally Unique Identifier 
Out Voice prosign: Contact completed, going back to listening 
OVC overcast 
Over Voice prosign: Transmission completed, go ahead 
OVR Overcast 
OWF Optimum Working Frequency, realtime version of FOT 
OWI Office of War Information, WW II 
OWVL One-Way Voice Link (example is "numbers") 
P greater than 
P Plus 
P Power (in watts) 
P/N Part number 
p/p (1)phone patch 
p/p (2)point-to-point 
p/p (3)peak-to-peak 
PA (1)Power amplifier 
PA (2)Public address system 
PA (3)Passenger agent 
PA (4)Privacy Act 
PA (5)Proceed Authority 
PAC (1)Pacific 
PAC (2)Personnel and Administration Center 
PAC (3)Political Action Committee 
PAC-3 Patriot Advance Capability 3 
PACAF Pacific Air Force (US) 
PACAREA Pacific Area (USCG) 
PACSAT Packet radio satellite 
PACTOR Packet teleprinting over radio (modes 1 and 2) 
PAD Packet assembler/disassembler 
PADAN PAcket Digital Amateur Network 
PADIL PATRIOT Digital Information Link (US missile batteries) 
PAL Plus 16:9 PAL 
PAL (1)Phase Alternating Line (W. Europe TV standard) 
PAL (2)Positive Arm Latches 
PAM (1)Phase-Amplitude Modulation, modems 
PAM (2)Pulse Amplitude Modulation 
PAM (3)Pluggable Authentication Modules (Linux) 
PAN Prosign: priority safety traffic follows (also "PAN PAN") [~] 
PANA Pan-African News Agency 
PAEW Persons And Equipment Working 
PAO Public affairs officer 
PAP (1)Polska Agencja Prasowa 
PAP (2)Password Authentication Protocol, computer networks 
PAPI Precision Approach Path Indicator 
PAR Precision Radar Approach, new name for GCA 
PARC Palo Alto Research Center (Xerox, obsolete) 
PASR personnel accounting and strength reporting 
PATRECONFOR Patrol and Reconnaissance Force (US Navy) 
PATWAS Pilot Automated Telephone Weather Answering Service 
PAVE PAWS Phased array SLBM warning system, 4 US Coastal sites 
PAVE Precision Acquisition Vehicle Entry 
PAWS (1)Phased Array Warning System, e.g., PAVE PAWS 
PAWS (2)Programmable Analyst Work Station 
PAWSS Ports and Waterways Safety System 
PAX (1)Passengers 
PAX (2)~"Peace" in Latin ("Pax Americana") 
PBBS Packet Bulletin Board System 
PBS Public Broadcasting System 
PBT Portable Breathalyzer Test (police drunk testing) 
PBX Private Branch Exchange (telco) 
PC (1)Personal Computer 
PC (2)Printed Circuit 
PCI Peripheral Component Interconnect (Intel) 
PCM Pulse code modulation 
PCMCIA Personal Computer Memory Card International Association 
PCN Personal Communication Network 
PCS (1)Personal Communication Service (mobile phone) 
PCS (2)Performance Control System 
PCS (3)Prelaunch Compatibility Station (GPS) 
PCS (4)Personal Communications System 
PDA Personal Digital Assistant (palmtop computer) 
PDC Personal Digital Cellular 
PDF Portable Document Format (Adobe) 
PDM Pulse Duration Modulation 
PDP Programmed Data Processor (DEC, 1960 on, classic machines) 
PDS Particularly Dangerous Situation (NOAA/NWS) 
PDT Pacific Daylight Time, US 
PDU Protocol Data Unit 
PE (1)ice pellets 
PE (2)Portable Executable (Micky$oft) 
PEM Privacy Enhanced Mail 
PEO-C3S Program Executive Office - Command, Control and Communications Systems 
PEO-IEWS Program Executive Office - Intelligence, Electronic Warfare and Sensors 
PEP Peak envelope power 
PER Packed Encoding Rules 
PERL Practical Extraction and Report Language, Unix scripting 
pers personnel 
PERSCOM Personnel command 
PEST Plasma Experiment Satellite Test 
pf Picofarad 
PF Pilot Flying 
PFC (1)Private, First Class 
PFC (2)Prepared Form Card, a homemade QSL for a station to sign 
PFRR Poker Flat Research Range, AK 
PGP Pretty Good Privacy, e-mail encryption program 
PHOTINT Photographic Intelligence (satellite pics, etc.) 
PHP PHP Hypertext Processor (a recursive acronym) 
PI protection interval 
PIC Programmable Interrupt Controller (computers) 
PIN Personal Identification Number 
pine Pine Is Nearly/Not/Not yet Elm, Unix mailer 
PING Packet InterNet Groper (ICMP "ping pong" tester for net) 
PIO (1)Public Information Officer 
PIO (2)Programmed Input/Output 
PIP Peripheral Interchange Program, old CP/M copy 
PIPEX Public IP EXchange (UK) 
PIREP Pilot Report, weather in standard form 
PIW Person(s) In Water 
PK WND peak wind 
PKW (1)German: Personenkraftwagen (passenger car) 
PKW (2)Polish: Polski Kontyngent Wojskowy (Polish Military Contingent, in KFOR) 
PL (1)"Private Line," Motorola tradename for CTCSS 
PL (2)Pilot light 
PL/1 Programming Language 1 (computer code) 
PLB Personal Locator Beacon 
PLC Power Line Carrier (Power company LF control system) 
PLIP Parallel Line Internet Protocol 
PLL (1)Phase Locked Loop 
PLL (2)prescribed load list 
PLS CW brevity: Please 
PM (1)Phase Modulation, slightly resembles FM 
PM (2)Post Meridian, hours between noon and 11:59 local 
PM (3)Project Manager 
PMBO Participating Mailbox 
PMC Personnel management center 
PMCS Preventive maintenance checks and services 
PME Protective Multiple Earth (ground) 
PMFC Pacific Missile Firing Center 
PMO Provost Marshall's Office 
PMRS Private Mobile Radio Service 
PMSV Pilot-to-Metro Service 
PM-TRCS Project manager, tactical radio communication systems 
PN Pseudo-Noise 
PNA Philippines News Agency 
PNF Pilot Not Flying 
PNO precipitation amount not available 
PNP Positive/Negative/Positive; transistor type 
PO dust/sand whirls (dust devils) 
POB Persons On Board 
POC Point of Contact 
POCSAG Post Office Code Standardization Advisory Group (paging) 
POD Point of debarkation 
POE Point of embarkation 
POES Polar Orbit Environmental Satellite 
POETS Push Off Early - Tomorrow's Saturday 
POL Petroleum, oils, and lubricants 
POL-ARQ Polish diplomatic ARQ teleprinter system 
POP (1)Post Office Protocol (Internet) 
POP (2)Point of presence 
POR Pacific Ocean Region (USCG) 
PORTS Physical Oceanographic Real-Time Systems 
POSIX OSI standard, like Unix 
POSIX Portable Operating System Interface 
POST Power-On Self Test 
pot Potentiometer [~] 
POTS (1)Plain Old Telephone System 
POTS (2)Plain Old Telephone Service 
POTS (3)Purchase Of Telephone Service (US Government) 
POTUS President Of The United States 
pp Phone patch 
PP Transmission is in Portuguese 
PPDL Point to Point Data Link 
PPE Personal Protective Equipment 
PPM (1)portable pixmap 
PPM (2)Page per minute 
PPM (3)Parts per million 
PPM (4)Pulse Position Modulation 
PPP Point-to-Point Protocol 
PPPoE Point-to-Point Protocol over Ethernet 
PPR Prior Permission Required (military landing permit) 
PPTP Point-to-Point-Tunneling Protocol 
PQM path quality matrix <acronym title="Page Ranking">PR</acronym> (1)Puerto Rico <acronym title="Page Ranking">PR</acronym> (2)Person Reporting (police) <acronym title="Page Ranking">PR</acronym> partial 
PRB Personal Radio Bureau (FCC) 
PRB-1 Personal Radio Bureau 1, FCC resolution attempting to preempt local radio laws 
PRB-1 Personal Radio Bureau-1 (FCC tower rule) 
PRC (1)Pseudo-Range Correction (DGPS) 
PRC (2)People's Republic of China 
prep preparation 
PRESRR pressure rising rapidly 
PRFG partial fog 
PRM Pulse rate modulation 
PRML Partial Response Maximum Likelihood (HD transfer mode) 
PROM Programmable Read Only Memory 
ProSEDS Propulsive Small Expendable Deployer System (NASA) 
Prosign Procedural Signal ("over," etc.) 
PRZ Polar Return to Zero 
PS/2 Personal System 2, IBM's less-than-sensational replacement for the PC 
PSA Public Service Announcement 
PSAP Public Safety Answering Point 
PSB Personnel services battalion 
PSDN Public Switched Data Network 
PSE CW brevity: Please 
PSK Phase-shift keying 
PSK-31 Phase-shift keyed very narrowband simplex direct printing scheme 
PSL Process Specification language 
PSM Pulse step modulation 
PSO Public service officer 
PSR Primary Surveillance Radar 
PSRAM Pseudo Static Random Access Memory, obsolescent 
PSS (1)Personnel service support 
PSS (2)Packet Switch Stream (British Telecom) 
PSSN pseudo sunspot number 
PST Pacific Standard Time, US 
PSTN Public Switched Telephone Network 
PSWAC Public Safety Wireless Advisory Committee 
PT (1)Preparedness, Training and Exercises Directorate (FEMA) 
PT (2)Patrol Torpedo (boat) 
PT (3)Permeability Tuned 
PTC Parallel Test Component (Linux) 
PTD Pilot-to-dispatcher 
PTO Permeability tuned oscillator 
PTR (1)Primary Training Range 
PTR (2)Puerto Rico 
PTR (3)Pointer [~] 
PTT (1)Push to talk 
PTT (2)Post, Telegraph and Telephone administration (UK) 
PU ("Papa Uniform") participating unit 
pub publication 
PUP Principal User Processor 
PVASI Pulsating Visual Approach Slope Indicator 
PVO private volunteer organization 
PWINO precipitation identifier sensor not available 
PWM Pulse width modulation 
PWR Power 
PY spray 
Q HectoPascals (U.S. METAR variant) 
Q Quality (measure of selectivity in inductive circuits) 
QA Quality Assurance 
QAM Quadrature Amplitude Modulation 
QCWA Quarter Century Wireless Association (amateur) 
QLF Facetious prosign: Now send with your LEFT foot 
QNH Set your altimeter to -- barometric pressure 
QoS Quality of Service 
QPC Question Pool Committee (amateur exams) 
QPSK Quaternary Phase Shift Keying 
QRA The name of my station is -- 
QRCT Quick Reaction Communications Terminal 
QRG (1)Your frequency is -- kHz 
QRG (2)The frequency is --, Kenneth 
QRH Drift ("Your frequency varies...") 
QRL I'm busy; frequency is in use 
QRL? (1)Are you busy? 
QRL? (2)Is this frequency in use? 
QRM Interference 
QRN Noise 
QRO (1)High power operation 
QRO (2)Please increase power 
QRP (1)Low power operation 
QRP (2)Please reduce power 
QRP (3)Quick Reaction Package (US Army vehicle) 
QRQ Please increase code sending speed 
QRR Old land distress call, now SOS, MAYDAY, or QRRR 
QRRR Old land distress call 
QRS Please reduce transmission speed 
QRSS (1)VERY low speed CW ("super QRS") 
QRSS (2)Quasi-Random Signal Source 
QRT (1)Station has ceased transmitting 
QRT (2)Please cease transmitting 
QRU I have no traffic for you 
QRU? Do you have traffic for me? 
QRV I am ready (go with your traffic) 
QRX Please standby 
QSA Signal strength 
QSB Fading 
QSD Your keying is defective 
QSK Duplex CW ("break-in") 
QSL (1)A card or letter confirming reception of a radio station 
QSL (2)Acknowledgment of transmission, a fancy "roger" 
QSO Communications between two or more stations 
QST (1)General call: "Hello all amateurs" 
QST (2)Ham radio magazine published by ARRL 
QSTAG Qadripartite Standardization Agreement 
QSV Send Vs 
QSV? Should I send Vs? 
QSX I am listening on... 
QSY (1) Frequency change 
QSY (2) Change frequency to -- kHz 
QTC Message 
QTH Location of station 
QWD Quarterly World Days, observation intervals 
QWERTY Name of standard typewriter keyboard, from top row of ltrs 
QWZ Facetious prosign: Are you woozy? I am woozy 
R chks Radio checks 
R (1)CW prosign: "Message received" 
R (2)DC resistance (in ohms) 
R (3)Resistor 
R (4)Right 
R (5)Runway 
R&D Research & Development 
R&O Report & Order (FCC) 
R/T Receiver/Transmitter 
R/W Rotary wing (helicopter) 
R3E Single sideband, reduced carrier (usually 6 dB) radiotelephony 
RA (1)Radio Authority (UK) 
RA (2)Rain 
RA (3)Radio Australia 
RA (4)File format: Real Audio 
RAA Royal Australian Army 
RAAF Royal Australian Air Force 
RAC-ARQ ARQ mode propietary to Racal/Thales 
RACES Radio Amateur Civil Emergency Service, FEMA affiliates 
Racon Radar Beacon 
RAD Radiological [~] 
Radar Radio Detection And Ranging 
RADARA Regional And Domestic Air Route Area 
RADAY Radio Day (US Mil) 
RADIL ROCC/AWACS digital information link 
RADINT (1)Radar intelligence 
RADINT (2)Radiation intelligence 
RADIUS Remote Authentication Dial In User Service 
RADM Rear Admiral 
RADMO Radio Mode 
RADSL Rate Adaptive Asymmetric Digital Subscriber Line 
RADSTA Radio Station 
RAF Royal Air Force 
RAG Replacement Air Group 
RAI Radio Televisione Italiana 
RAID (1)Redundant Array of Inexpensive Disks (servers) 
RAID (2)Rapid Assessment and Initial Detection team (FEMA/Army NG) 
RAIL Runway Alignment Indicator Lights 
RAM Random Access Memory (can be changed) 
RAMAC Random Access Method Of Accounting And Control (IBM, 1956) 
RAMDAC Random Access Memory Digital to Analog Converter 
RAMP Radar Modernization Project 
RAN Royal Australian Navy 
RAOC rear area operations center 
RAPCON Radar approach control 
RARP Reverse Address Resolution Protocol 
RAS Remote Access Server 
RASC Radio Atmospheric Science Center (Japan) 
RASP Radio Science And Propagation 
RATCF Radar Air Traffic Control Facility (USN) 
RATS Radio Amateur Telecommunications Society 
RATT Radioteletype (usually military 75/100 bd) 
RAV Restricted Availability 
RB Radar Beacon 
RBL Realtime Blackhole List (Internet) 
RBL Realtime Blackhole List (spam filtering) 
RBS Radar Bomb Scoring 
RC (1)Reserve Components (US Army) 
RC (2)Radio control 
RCA Radio Corporation of America 
RCC (1)Rescue Coordination Center (GMDSS) 
RCC (2)Range control center (USAF) 
RCC (3)Resource control complex 
RCC (4)Rag Chewer's Club (ham award) 
RCCC Range communications control center 
RCDS Raster Chart Display System 
RCI Radio Canada International 
RCMA Dead scanner radio club, which included HF utility 
RCNC Range communications network controller 
RCNY Rules of the City of New York 
RCO Range Control Officer 
rcp Remote Copy (unix) 
RCP Resource Change Proposal 
RCR Runway Condition Reading 
RCS (1)Radio Communication System 
RCS (2)Reaction Control System (NASA) 
RCS (3)Radar cross-section 
RCS (4)Radio Conference Subcommittee (of IRAC) 
RCS (5)Remote Control System 
RCS Radio Conference Subcommittee 
rcv Receive mode 
rcvr receiver 
RD (1)replacement directorate 
RD (2)Restricted data 
RD (3)Regional Director 
RD Radar man (old USCG grade) 
RDARA Regional and Domestic Air Route Area 
RDEC Research, Development and Engineering Center (Army) 
RDF (1)Radio direction finding 
RDF (2)Resource Description Framework 
RDF (3)Resource Description Format 
RDF (4)Rapid Deployment Force 
RDF (5)Repeater Distribution Frame (telephony) 
RDF (6)Raw Data File 
RDF (7)Record Description Field 
RDM (1)Radio Data Modem 
RDM (2)Radio Diffusion Marocaine (Morroco) 
RDNS Reverse Domain Name System lookup (Internet) 
RDRAM RAMBUS (company) Dynamic Random Access Memory 
RDS Remote Data Service 
RDT Remote digital terminal 
RE Reverse engineering 
REACT Radio Emergency Associated Communication Team, like ARES, but on CB and GMRS 
REC Radio-electronic combat 
rec receive 
recon reconnaissance 
REDHORSE Rapid Engineer Deployable Heavy Operational Repair Squadron, Engineer 
REE Radio Exterior de Espana (Spain overseas broadcaster) 
Reg regulation, includes radio rules 
REJ Packet control frame: Reject, data out of sequence 
Rem (1)Remark (computer programming) 
Rem (2)Radiation------alent, man (nuclear safety) 
REP Radiological Emergency Preparedness (program) 
REQ request 
req'd required 
RETMA Radio, Electronics, Television Manufacturers Assn, now EIA 
retrans retransmission 
rev reverse 
RF Radio Frequency 
RF/EMPINT Radio Frequency/Electromagnetic Pulse Intelligence 
RFC (1)RF Choke 
RFC (2)Request For Comment (Internet standards) 
RFDS Royal Flying Doctor Service (Australia) 
RFDU RF distribution unit 
RFE Radio Free Europe 
RFI (1)RF Interference 
RFI (2)Radio France International 
RFID Radio Frequency Identification 
RFP Request For Proposals 
RFPI Radio For Peace International, Costa Rica 
RFR RF radiation 
RG-# Radio Guide, Radio Group, Radio Grade (differs) - coax cable designator 
RGB Red, Green, Blue; additive color mixing like TV 
RGS Remote ground station 
RHC Radio Havana Cuba 
RHCP Right-hand circular polarization 
RHOJ Radar home on jam 
RI (1)Routing indicator (Telex or radiograms) 
RI (2)Ring Indicator (modem line) 
RIAA Recording Industry Assn of America (audio) 
RIFF Resource Interchange File Format (Microsoft MIDI) 
RIMM (1)RAMBUS In-Line Memory Module 
RIMM (2)Removable Interchangeable Media Module 
RIO (1)Radar Intercept Officer 
RIO (2)Relative Ionospheric Opacity 
Riometer Relative Ionospheric Opacity Meter (uses cosmic RF) 
RIPE Regional Internet Registry for Europe 
RIPE Reseaux IP Europeens (Internet registry) 
RISC Reduced Instruction Set Computing, chip architecture 
RIT Receiver Incremental Tuning, same as "clarifier" 
RITL Radio In The Loop (telephony) 
RJ Radio Japan 
RLC Resistance-Inductance-Capacitance (network) 
Rlogin Remote Login, networking program like telnet 
RM (1)("Romeo Mike") Radioman, radio operator 
RM (2)Radio Man (old USCG grade, became TC) 
RM (3)File extension: Real Media 
RMA (1)Revolution in Military Affairs (US tax subsidized paper crunching) 
RMA (2)Return Merchandise Authorization 
RMA (3)Reduced Major Axis) 
RMA (4)Old Microsoft midi file format (see MIDI) 
RMC Regional Meteorological Center 
RMI (1)Radio Magnetic Indicator 
RMI (2)Republic of the Marshall Islands 
RMI (3)RIFF MIDI (an acronym made up of acronyms) 
RMI (4)Radio Miami International 
RMK Remarks 
RMP (1)Radio Mobile Patrol (NYPD car) 
RMP (2)Radio Motor Patrol 
RMP (3)Radio Móvil Privada (Spanish: Private Mobile Radio) 
RMP (4)Raster Map Product 
RMP (5)Radio Merkury Poznan (Poland) 
RMS (1)Royal Majesty Ship 
RMS (2)Royal Mail Steamer (obsolete?) 
RMS (3)Root Mean Square 
RMS (4)Remote Mine Sweeping 
RMS (5)Radar Manual Systems 
RMS (6)Remote Manipulator System (space shuttle's robot arm) 
RMTN Region IV Meteorological Telecommunication Network 
RN (1)Radio Netherlands 
RN (2)Royal Navy 
RN (3)Registered Nurse 
RN (4)Revision Notice 
RN Radio Netherlands 
rn Read News, usually the default Unix Usenet reader 
RNR Packet control frame: Receive Not Ready 
RNZ Radio New Zealand 
RNZAF Royal New Zealand Air Force 
RNZI Radio New Zealand International 
RNZN Royal New Zealand Navy 
RO (1)Radio Officer (traditionally trained in Morse code) 
RO (2)Receive Only 
ROA Remotely Operated Aircraft 
ROC (1)Regional Operating Center (FEMA/NCS) 
ROC (2)Rear operations center 
ROC (3)Reservoir Operating Center (USACE) 
ROCC Regional Operations Control Center 
ROE Rules Of Engagement 
ROFL Rolling On Floor Laughing (Internet, also ROTFL) 
ROFOR Route Forecast 
Roger Voice Prosign: Message Received (from "R" in Morse code) 
ROLAP relational on-line analytical processing (databases) 
ROM Read Only Memory (can't easily be changed) 
ROMPRES Romanian press agency 
RON Remain Over Night (US military) 
ROSE RATS Open System Environment (Packet; see RATS) 
ROTATE Radar Observations of Tornadoes And Thunderstorms Experiment 
ROTFL Rolling On The Floor Laughing (Internet, also ROFL) 
ROTHR Relocatable (HF) Over-The-Horizon Radar 
ROTR Receive-Only Typing Reperforator (tape printer) 
ROVER Remote Out-of-Vehicle Emergency Radio (LAPD) 
RP (1)Received Pronunciation (British radio "accent") 
RP (2)Reporting Party (Police) 
RPA (1)Remote Passphrase Authentication 
RPA (2)Radio-Programming Application 
RPC Remote Procedure Call (lousy Windoze security) 
RPG Report Program Generator (strange IBM computer language) 
RPI Runway Point of Intercept 
RPM Red (Hat) Package Manager (Linux) 
rpm Rotations per minute 
RPN Reverse Polish Notation (computing) 
rpt (1) Reception report 
rpt (2) CW prosign: repeat 
Rptr Repeater 
RPU Remote Pickup Unit 
RQ (1)Repeat Request 
RQ (2)Request acknowledgment of receipt (DSC protocol) 
RQS Request to send (modem handshaking line, rare name for RTS) 
RR (1)Transmission is in Russian 
RR (2)Radio Regulation (ITU) 
RR (3)Railroad (don't laugh, some use HF) 
RR (4)Packet control frame: Receive Ready 
RR (5)Response and Recovery Directorate (FEMA) 
RR (6)Radio Reloj (clock radio, SS news format) 
RRC (1)Regional Radio Conference (ITU) 
RRC (2)Range Rate Correction (DGPS) 
RRP Runway Reference Point 
RRSS Radparker Relay Spam Stopper 
RRx Routine Report, where x is a sequential letter, used for delayed METAR 
RS (01)radiated susceptibility 
RS (02)range squadron 
RS (03)reentry system 
RS (04)requirements submission 
RS (05)resource scheduling 
RS (06)Radio Satellite (Russian amateur) 
RS (07)EIA Recommended Standard, RS-232 was one 
RS (08)Record Separator (ASCII) 
RS (09)Radio Sweden 
RS (10)Reference Station 
RS-232 Recommended Standard 232, standard serial I/O, now EI-232 
RSA (1) Rivest-Shamir-Adelman, inventors of a proprietary type of public-key encryption 
RSA (2)Republic of South Africa 
RSGB Radio Society of Great Britain 
rsh Restricted shell (Unix) 
RSN Real Soon Now (when everything is going to happen) 
RSO Range Safety Officer 
RSOC Regional SIGINT Operation Center (like Menwith, UK) 
RSS (1)Really Simple Syndication (world wide web) 
RSS (2)Radio Subsystem 
RSS (3)RDF Site Summary (see RDF #2) 
RSS (4)Rich Site Summary 
RST (1)Signal report: Readability, Strength, [Tone] (if CW) 
RST (2)Reset 
RSTA reconnaissance, surveillance and target acquisition 
RSVP (1)Resource Reservation Protocol 
RSVP (2)Repondez Si'Vous Plait (Please Respond, party invitations) 
RT (1)Radiotelephone 
RT (2)Receiver-transmitter 
RT (3)Receive Timing 
RT (4)routing table 
RTB Return to base 
RTC Rail Traffic Control 
RTCA Radio Technical Commission for Aeronautics 
RTCE Reat-Time Channel Evaluation 
RTCM Radio Technical Commission for Maritime (services) 
RTCP Real Time Control Protocol 
RTD Return to duty 
RTDC Real time data controller 
RTE Radio Telefs Éireann (Ireland) 
RTF (1)Radiodiffusion Television Francais 
RTF (2)Runtime file 
RTFM Read the [fine] manual 
RTFMS Real-Time (HF) Frequency Management Software 
RTHK Radio Television Hong Kong 
RTLS (1)Return to launch site 
RTLS (2)Real-Time Locating Systems 
RTO (1)Responsible Test Organization (US) 
RTO (2)Radiotelephone Operator (LAPD) 
RTO (3)Range training officer 
RTOK Retest OK 
RTOS Real Time Operating System 
RTS Request To Send (secondary handshaking modem line) 
RTT (1)Radioteletype 
RTT (2)Radio Transmission Technology 
RTTY Radioteletype 
RTZ Return To Zero 
R-UIM Removable User Identity Module 
RVR Runway Visual Range 
RVRNO RVR system not available 
RWI radio wire integration (changed to NRI-net radio interface) 
RWR Radar Warning Receiver 
RWY runway 
RX (1)Receiver 
RX (2)Religious programming 
RX (3)Retransmission 
RXD Received Data (Serial I/O) 
RXR Receive Reversed (usually RTTY Mark/Space) 
RY RYRYRY teleprinter test call 
RZ Return to Zero 
S (1)south 
S (2)Siemen 
s second 
s/n Serial number 
S/N Signal/Noise ratio 
S/NR Signal/Noise Ratio 
s/off Sign off 
s/on Sign on 
s/w software (computer programs and instructions) 
S&TCD Space and Terrestrial Communications Directorate 
S1 Adjutant (US Army) 
S2 Intelligence Officer (US Army) 
S3 Operations and Training Officer (US Army) 
S3A Supervised Standard Scientific Analysis 
S4 Supply Officer (US Army) 
SA (1)South Atlantic 
SA (2)Sand 
SA (3)Situational Awareness 
SA (4)Selective Activation (GPS) 
SAA South Atlantic Anomaly, a large magnetic deviation 
SAAF Small Austere Air Field 
SAAFR Standard use Army Aircraft Flight Route 
SABC South African Broadcasting Corporation 
SABM Packet control frame: Set Async Balanced Mode (connect) 
SAC Strategic Air Command, now part of US Stratcom 
SACCS Strategic Automated Command & Control System 
SACD Super Audio Compact Disk (Sony/Philips) 
SACEUR Supreme Allied Command(er) Europe 
SACLANT Supreme Allied Commander, Atlantic {NATO} 
SAE Self Addressed Envelope (usually with IRC or "green stamp") 
SAFE Selected Area For Evasion 
SAGE Semi-Automated Ground Environment (early, huge, USAF system) 
SAID Sub-Auroral Ion Drift 
SALS Short Approach Lighting System 
SAM (1)Special Air Mission (US Air Force VIP flight) 
SAM (2)South America (MWARA) 
SAM (3)Surface-to-Air missile 
SAMCOM Special Air Missions Communications ("Mystic Star") 
SAME Specific Area Message Encoding (US weather warnings) 
SANA Syrian Arab News Agency 
SAO (1)South Atlantic Ocean 
SAO (2)Surface Aviation Observation (weather) 
SAP (1)Second Audio Program 
SAP (2)Special-Access Program 
SAP (3)Soon As Possible, when every radio project has to be done 
SAR (1)Search and rescue 
SAR (2)Synthetic Aperture Radar 
SAR (3)Station Availability Report (SHARES) 
SARAH Standard Automated Remote to Autodin Host 
SAREX Shuttle Amateur Radio Experiment 
SARNET NOAA SARSAT Network 
SARSAT Search And Rescue Satellite 
SART (1) Survival Craft Radar Transponder 
SART (2) Search And Rescue Transponder 
SARTG Scandinavian Amateur Radio Teleprinter Group 
SASE Self Addressed Stamped Envelope 
SAT (1)South Atlantic (MWARA) 
SAT (2)Satellite 
SAT (3)Saturday 
SATAN Security Administrator Tool for Analyzing Networks 
SATCOM Satellite communication 
SATERN Salvation Army Team Emergency Radio Network 
SAVASI Simplified Abbreviated Visual Approach Slope Indicator 
SAWS Stand Alone Weather System 
SB (1)Standby (EIA-449) 
SB (2)Sierra Bravo, son of a [female dog] 
SB (3)Sideband 
SBA (1)Sovereign Base Area 
SBA (2)Small Business Administration 
S-band 1.55-5.2 Ghz microwave band 
SBCS Single Byte Character Set 
SBD Safe Braking Distance (railroad) 
SBD1 Safe Braking Distance + 1 minute (also SBD2, etc) 
SBE Society of Broadcast Engineers 
SC Sudden commencement (of a magnetic storm; causes fadeouts) 
SC-104 Special Committee #104 (DGPS Standard) 
SCA (1)Subsidiary Communications Authorization (US commercial FM) 
SCA (2)Shuttle Carrier Aircraft (NASA's modified 747 for transporting orbiter) 
SCADA Supervisory Control and Data Acquisition System 
SCAMP Single-Channel Antijam Man-Portable 
SCAT Strategic Communications (Continuing) Assessment Program 
SCBA Self-Contained Breathing Apparatus 
SCCS satellite communications control system 
SCDCC Southern California Digital Communications Council (Amateur) 
SCDX Sweden Calling DXers 
SCDXC Southern California DX Club 
SCI San Clemente Island (USN, CA) 
SCMA Southern California Monitoring Association 
SCN (1)System Coordination Net (US Coast Guard) 
SCN (2)SHARES Coordination Net (US NCS/SHARES) 
SCO (1)Subcarrier oscillator 
SCO (2)Santa Cruz Organization, a software source 
SCO (3)State Coordinating Officer (FEMA/NSEP) 
SCOPE System Capable Of Planned Expansion (Scope Command) 
SCPC Single channel per carrier 
SCPT Single channel per transponder 
SCR Silicon controlled rectifier 
SCRAM Scramble; automated fast shutdown of nuclear reactor [~] 
SCRRBA Southern California Repeater/Remote Base Assn (Amateur) 
SCS Satellite Control Squadron 
SCSI Small Computer System Interface ("scuzzy") 
SCSL stratocumulus standing lenticular cloud 
SCT Scattered clouds 
SCTP Stream Control Transmission Protocol 
SDARS Satellite Digital Audio Radio Service (Sirius & XM) 
SDF Simplified Directional Facility 
SDH Synchronous Digital Hierarchy 
SDI Strategic Defense Initiative, U.S. space money sink 
SDLC Synchronous Data Link Control, bitwise computer comm protocol 
SDLP Station Data Link Protocol 
SDNRIU Secure Digital Net Radio Interface Unit 
SDR Software Defined Radio 
SDRAM Synchronous Dynamic Random Access Memory 
SDSL Symmetric Digital Subscriber Line 
SDTV Standard Definition Television 
SDU Secure data unit 
SDX Semi-duplex 
SE Southeast 
SEA Southeast Asia (MWARA) 
SEAD Suppression of Enemy Air Defenses 
SEAL Sea, Air, Land (US Navy special op teams) 
SEAM Space Emergency Action Message 
SEATO South East Asia Treaty Organization (now ASEAN) 
sec Second 
SEC Software Engineering Center (Army) 
SECAF Secretary of the Air Force 
SECAM (1)SEquentiel Couleur A Memoire, weird French TV standard, adopted by Russian bloc to keep out Western TV 
SECAM (2)Simply Everything Contrary to America 
SECDEF Secretary of Defense (US) 
SECT SHARES Emergency Coordination Team 
SECURE State Emergency Capability Using Radio Effectively 
SECURITE Prosign: safety traffic follows; uses FF pronunciation SEE-CURE-EE-TAY 
SEDENA Secretaria de la Defensa Nacional (Mexico) 
SEE Stimulated Electromagnetic Emissions 
SELCAL Selective Calling (tones or numbers) [~] 
SELFEC Selective FEC 
SELSCAN Proprietary name for Collins scanning ALE HF radio system 
SENS System Event Notification Service (Windows) 
SENSAPI System Event Notification Service API (nested acronym) 
SENSE Synthetic Environments for National Security Estimates 
SEP Solar Energetic Particle Event (observation interval) 
SES Ship Earth Station 
SESC Space Environmental Services Center 
SESEF Ship Electronic Systems Evaluation Facility (US Navy) 
SETI Search for Extra-Terrestrial Intelligence (by radio) 
SEVOCOM Secure voice communications 
SEW Space & Electronic Warfare 
SF Special Facility 
SFA Single Frequency Approach 
SFC surface 
SFCG Space Frequency Coordination Group 
SFDU Standard formatted data unit 
SFF Small Form Factor (hard disks) 
SFU Solar flux unit 
SG Signal ground 
SG snow grains 
SGIN Subgroup Identification Number (FCC) 
SGML (1)Standard Generalised Markup Language 
SGML (2)Standard Generalized Markup Language 
SGRAM Synchronous Graphic Random Access Memory 
SGT Sergeant 
SH (Rain) Showers 
sh Bourne Shell, originally the Unix default command interpreter 
SHA-1 Secure Hash Algorithm-1, US code 
SHAEF Supreme Headquarters, Allied Expeditionary Forces 
SHAPE Supreme Headquarters, Allied Powers, Europe 
SHARES SHAred RESources, part of US Federal NCS 
SHF super high frequency 
SHIFOR Stastical Hurricane Intensity FORecast 
SHIPS Stastical Hurricane Intensity Prediction Scheme 
SHOALS Scanning Hydrographic Operational Airborne LIDAR Survey 
SHTTP Secure Hypertext Transfer Protocol (web) 
SI (1)Systeme Internationale d'Unites; a standard unit system 
SI (2)Shift In (Baudot & ASCII) 
SIC (1)Service Identification Code 
SIC (2)Standard Industrial Classifification 
SIC (3)Standards Implementation Committee 
SIC (4)Specific Inductive Capacity 
SID Sudden Ionospheric Disturbance (solar flare effect) 
SIG (1)Signature [~] 
SIG (2)Special Interest Group 
SIGCEN signal center [~] 
SIGINT Signals Intelligence [~] 
SIGMET Significant Meteorological warning signals [~] 
SILENCE MAYDAY Voice prosign: frequency is on standby for distress traffic; uses FF pronunciation SEE-LONCE MAY-DAY 
SIM (Card) Subscriber Identity Module 
SIMM Single In-line Memory Module 
SIMMS Single In-line Modular Memory System 
SIMOP Simultaneous Operation (of radios; an interference standard) 
Simul Simulcast 
SINAD signal-plus-noise-plus-distortion to noise-plus-distortion ratio 
SINCGARS Single-Channel Ground/Airborne Radio System 
SINPFEMO Signal report: adds modulation and propagation details 
SINPO Signal report: adds Noise, Propagation to SIO 
SINS Ship's Inertial Navigation System 
SIO (1)Signal report: Strength, Interference, Overall (1-5) 
SIO (2)Serial Input/Output 
SIOP Single Integrated Operational Plan 
SIOPS Special Intelligence Operations 
SIPRNET Secret IP Router Network (military's own Internet w/NIPRNET) 
SIR Subsurface Interface Radar 
SIRTF Space Infrared Telescope Facility (NASA) 
SIS (1)Secret Intelligence Service (aka MI6, UK) 
SIS (2)Scramble Information Service (Dutch planespotter network) 
SITFAA Inter-American Air Forces Telecommunications Network (Spanish) 
SITOR (1) Simplex Teleprinting Over Radio 
SITOR (2) Simplex Telex Over Radio 
SITOR-A Simplex teleprinting over radio system, mode A (ARQ) 
SITOR-B Simplex teleprinting over radio system, mode B (FEC) 
SITREP Situation report 
SITSTAT Situation status 
SIU Server Interface Unit 
SJA Staff judge advocate 
SK CW prosign: "End of transmission," usually written VA 
SKC Sky clear 
SKYWARN NWS/ARRL amateur severe weather spotting network 
SLAM Standoff Land Attack Missile 
SLB Single Letter Beacon (Russian Navy marker xmsn) 
SLBM Sea-Launched Ballistic Missile 
SLC Space Launch Complex 
SLEP Service Life Extension Program 
SLHFB Single-Letter High-Frequency beacon (see SLB) 
SLIP Serial-Line Internet Protocol, older than PPP 
SLOC Sea lines of communication 
SLOSH Sea, Lake, and Overland Surges for Hurricanes 
SLP (1)Seaward Launch Point 
SLP (2)sea-level pressure 
SLPNO sea-level pressure not available 
SLR Shielded Loop Receiver 
SLS Space Launch Squadron 
SM Statute Miles 
SMART (1)Self Monitoring Analysis and Reporting Technology 
SMART (2)Self-Managed Arrival Resequencing Tool 
SMART (3)Segmented Method for Analytical Ray-Tracing 
SMART-T Secure Mobile Antijam Reliable Tactical Terminal 
SMASH Synchronous Multi-channel Access Signalling for HF 
SMB Server Message Block (Windows) 
SMC Space and Missile Center 
SMEX Small Explorer (Goddard/NASA) 
SMF Special Message Field 
SMMW Sub-millimeter wave 
SMRS Specialized Mobile Radio System 
SMS Short Message Service (text) 
SMSI Sommet Mondial sur la Société de l'Information 
SMT Surface mount technology 
SMTP Simple Mail Transfer Protocol (Internet) 
SN (1)Serial number 
SN (2)Snow 
SNA System Network Architecture 
SNAFU Situation Normal All [Fouled] Up 
SNINCR snow increasing rapidly 
SNMP Simple Network Management Protocol, computers 
SNR Signal to Noise Ratio 
SNSM Société Nationale de Sauvetage en Mer (French National Society for Ocean Rescue) 
SO DIMM Small Outline Dual Inline Memory Module 
SO (1)Sheriff's Office 
SO (2)Shift Out (ASCII) 
SOA School Of the Americas (now WHISC) 
SOAP Simple Object Access Protocol (Internet) 
SOAR Special Operations Air Regiment 
SOB Souls On Board, number of people on an aircraft 
SOCOM Special Operations Command (US Navy) 
SODIMM Small Outline Dual In-line Memory Module 
SOF (1)Special Operations Forces 
SOF (2)Safety Of Flight 
SOH Start Of Heading (ASCII) 
SOHFRAD Special Operations High Frequency Radio 
SOHO (1)Solar Heliospheric Observatory (satellite at Lagrange point) 
SOHO (2)Small Office/Home Office (computing) 
SOI (1)Signal of interest 
SOI (2)Signal operation instructions 
SOI (3)Space Object Identification (NORAD) 
SOIR Simultaneous Operations on Intersecting Runways 
SOJ Small Outline J-lead 
SOL [Spit] Out of Luck 
SOLAS Safety Of Life At Sea (series of international treaties) 
Sonar Sound detection & ranging 
SONET Bell spec for data transmission over optical fiber 
SONGS San Onofre Nuclear Generating Station 
SOP Standing/Standard operating procedure 
SOPS Space Operations Squadron 
SOS Morse distress call, sent as one long character, replaced CQD [~] 
SOSB special operations support battalion 
SOSEC Surveillance Observation Satellite Evaluation Center 
SOSEX SOSUS Exercise 
SOSS (1)Sound Search Stations 
SOSS (2)Soviet Ocean Surveillance System 
SOSUS (1)Sound Surveillance Underwater System; network of hydrophones across Bering Straight to listen for Russian subs 
SOTDMA Self-Organizing Time Division Multiple Access 
SOUTHCOM Southern Command 
SOW (1)Start Of Watch 
SOW (2)Statement Of Work 
SP (1)South Pacific (MWARA) 
SP (2)Silent Period (500 kHz CW watch, obsolete) 
SP (3)Shore Patrol (US Navy MPs) 
SP (4)Space (RTTY) 
SPAC Spectrum Planning and Policy Advisory Committee 
SPACECOM US Space Command 
SPAR (1)Special Air Resources, US Air Force VIP flight 
SPAR (2)Seagoing Platform for Acoustic Research 
SPC Storm Prediction Center (NOAA) 
SPDT Single-Pole, Double-Throw 
SPDU HFDL: Squitter Protocol Data Unit 
SPE Satellite Proton Event; solar-terrestrial disturbance 
SPECI (1)Aviation Selected Special Weather Report, from French 
SPECI (2)an unscheduled report taken when certain criteria have been met 
SPEEDX Society for the Preservation of the Engrossing Enjoyment of DXing. I believe that an old "bug" key had this tradename as well. 
SPF Shortest Path First 
SPI (1)Service Provider Interface 
SPI (2)Stateful Packet Inspection 
SPINCOM Special Intelligence Communications 
Spkr Speaker 
SPL Sound Pressure Level 
SPL/1 High-Order Signal Processing Language #1 
SPO Security, plans, and operations 
SPOD Seaport of debarkation 
SPS (1)Spectrum Planning Subcommittee (of IRAC) 
SPS (2)Standard Positioning Service 
SPS (3)Service Propulsion System (Apollo project) 
SPSS Space Surveillance Squadron 
SPST Single-Pole, Single-Throw 
Spt Support 
SPTT Security Policy Translation Table 
SPX Sequenced Packet Exchange 
SQ squalls 
sqdn Squadron 
SQL Structured Query Language (computer databases) 
SQPSK Staggered Quadrature Phase Shift Keying (like OQPSK) 
SR Special Reconnaissance (SR-71 "Blackbird") 
SRA Specialized repair activity 
SRAM Static Random Access Memory 
SRB Solid-Rocket Booster(s), NASA Space Shuttle, recovered by BRV 
SRMS Smart Resource Management System 
SRWBR Short Range Wide Band Radio 
SS (1)Transmission is in Spanish 
SS (2)Sandstorm 
SS (3)Shifting Standards (computer marketing technique) 
SS (4)Steam Ship 
SSA Supply support activity 
SSB Single Sideband 
SSC Sudden Storm Commencement (geophysics) 
SSD Satellite Services Division (NOAA) 
SSE South-southeast 
SSE-CMM Systems Security Engineering-Capability Maturity Model 
SSEC Selective Sequence Electronic Calculator (IBM, 1948) 
SSF Southern Straits of Florida 
SSG The Space Systems Group 
ssh Secure Shell (Unix) 
SSI Server Side Includes (web) 
SSI Space Science Institute 
SSID (1)Secondary Station Identifier (packet) 
SSID (2)Service Set Identifier (wireless networking) 
SSL Secure Sockets Layer (encrypted TCP/IP computer networking) 
SSN (1) Sunspot Number 
SSN (2) Nuclear Submarine (US Navy) 
SSN Social Security Number (same as TIN - FCC forms) 
SSOM Spanish language numbers transmission, male voice 
SSPAR Solid State Power Amplifier-Receiver 
SSR (1)Secondary Surveillance Radar 
SSR (2)Soviet Socialist Republic (obsolete) 
SSR/IFF Secondary Surveillance Radar/Identification Friend or Foe 
SSRAM Synchronous Static Random Access Memory 
SSRC Single Sideband, Reduced Carrier 
SSSC Single Sideband, Suppressed Carrier 
SST (1)Supersonic Transport (aircraft) 
SST (2)Sea Surface Temperature 
SSTV Slow Scan Television 
SSW South-southwest 
SSYL Spanish language numbers transmission, female voice 
ST Send Timing (EIA-449) 
STA (1)Status (packet) 
STA (2)Special Temporary Authority (from FCC, to do something) 
STAJ Short Term Anti-Jam (makes gurgling noise on-air) 
STAMIS Standard Army Management Information System 
STANAG Standardization Agreement (NATO) [~] 
STAR SHARES Transportable Auxiliary Radio 
STARC State Area Command (Army NG) 
STARS (1)Space-based Telemetry And Range Safety 
STARS (2)Secure Tactical Army Radio System 
STARS (3)Standard Terminal Automation Replacement System 
STARS-V Secure Tactical Army Radio System-VHF 
STAT Old CP/M status command, replaced in version 3.0 
STCICS Strike Command Integrated Communications System (RAF) 
STD (1)Standard 
STD (2)Solar-Terrestrial Dispatch, Canadian auroral warning center 
STG Satellite Tracking Group 
STK Strike Control 
sTLD Sponsored Top Level Domain (.aero, .coop, etc) 
Stn Station 
STP Shielded Twisted Pair (cable) 
STPD standard temperature, pressure, dry 
STRATCOM U.S. Strategic Command 
STS Space Transport System, the "Space Shuttle" 
STSA Standard Telemedicine System Architecture 
STT Shore Targeting Terminal 
STU Secure Telephone Unit 
STU-III Secure Telephone Unit, Third Generation 
STX Start Of Text (ASCII) 
SUA/ISE Special Use Airspace/Inflight Situational Enhancement 
SUB Substitute (ASCII) 
SUNA Sudan News Agency 
SUO Small Unit Operations 
SuperDARN Super Dual Auroral Radar Network 
suppl supplement 
SURFnet Dutch academic network 
SUV Sport-Utility Vehicle 
svcs services 
SV-CW-C Greek Telegraphy Club, aka GTC 
SVP (1)Single Line Variety Package (telco) 
SVP (2)Si Vous Plait ("If you please" in French) 
SVT (1)Sveriges Television (Swiss TV network) 
SVT (2)Secure Voice Terminal 
SW (1)Shortwave (high frequency - HF) 
SW (2)Southwest 
SWBC Short Wave Broadcasting 
SWED-ARQ Swedish ARQ teleprinter system, used by that country 
SWF Short Wave Fadeout (ionospheric disturbance) 
SWI Special World Interval, unscheduled radio astronomy observation period caused by solar event 
SWL Shortwave Listener 
SWR (1)Standing Wave Ratio 
SWR (2)Surface-Wave Radar 
SWS Standard Workstation (US Coast Guard) 
SX (1) Simplex 
SX (2) Old Hallicrafters prefix, usually meant radio had xtal filter 
SYMPA Systeme de Multi-Postage Automatique (French mailing list program) 
SYN Synchronous Idle 
SYNOP Synoptic weather reports (from surface observations) 
Sysop System Operator, the king on a BBS 
T (1)US Coast Guard C3 office, DC; aka G-T 
T (2)Boston transit system 
t Time (in seconds) 
T/R Transmit/Receive switching 
T1 Relatively high speed data connection over phone line 
T2FD Terminated, Tilted, Folded Dipole 
tac tactical 
TAC Tactical Air Command, now ACC 
TAC Technical Advisory Committee 
TACACS Terminal Access Controller Access Control System (Cisco) 
TACAMO Take Charge And Move Out (US Navy CP aircraft) 
TACAN Tactical Air Navigation 
TACC (1)Tanker/Airlift Command Center (US AMC) 
TACC (2)Tactical Aircraft Control Center (US) 
TACFIRE Tactical fire direction system 
TACS Terminal Access Conversion Service (UK) 
TACS Traffic Alert and Collision Avoidance System 
TACSAT Tactical satellite 
TACSATCOM tactical satellite communications 
TACT Tailored Annual Cutter Training (USCG) 
TACTS Tactical Aircrew Combat Training System 
TAD Temporary Additional Duty 
TADIL Tactical Digital Information Link (US) 
TAF Terminal Aerodrome Forecast, aviation weather 
TAFB Tropical Analysis and Forecast Branch (TPC) 
TAI International Atomic Time 
TAL Transoceanic Abort Landing (space shuttle) 
TALCE Tanker Air Lift Control Element 
TANJUG Old Yugoslav news agency 
TAO Tactical Action Officer 
TAOC Tactical Air Operations Center 
TAP Telocator Alphanumeric Protocol (paging) 
TAPR Tuscon (AR) Amateur Packet Radio, ham software source 
tar Tape Archive, Unix backup/archive program 
TARBS Television and Radio Broadcasting Services (Australia) 
TARPS Tactical Airborne Reconnaisance Pod System 
TARPS-DI TARPS Digital Imagery 
TAS True Air Speed 
TASCOMM Tactical Air-Sea Communications (UK) 
TASMA Two-meter Area Spectrum Management Assn. (Amateur) 
TAW Tactical airlift wing 
TAWC Tactical Air Warfare Center 
TBA To Be Announced 
TBD To Be Determined 
TC Telecommunications Specialist (old USCG grade, was RM) 
TCAS Traffic (Alert) & Collision Avoidance System 
TCC Telecommunications center 
TCF Tactical combat force 
TCH Threshold Crossing Height 
TCM Trellis Coded Modulation 
TCN Track Condition Notice (railroad) 
TCP Transmission Control Protocol 
TCP/IP Transmission Control Protocol/Internet Protocol 
TCPA Time to Closest Point of Approach 
TCPOD Tropical Cyclone Plan Of the Day 
TCS (1)Tactical Control System 
TCS (2)Tactical Camera System 
TCU Towering Cumulus 
TCWF Terminal Convective Weather Forecast 
TD (1)Transmitted Data, short for TXD 
TD (2)Transmitter/Distributor (old RTTY) 
TD (3)Tropical Depression 
TDA Table of distribution and allowances 
TDD Time Delay Distortion 
TDM Time-Division Multiplex 
TDMA Time Division Multiple Access 
TDOA Time Difference Of Arrival 
TDP Takeoff Decision Point 
TDU Threat Display Unit 
TDY Temporary duty ("to go TDY") 
TEC Total Electron Content (of ionospheric region) 
TECG Tactical Exercise Control Group 
TEI Text Encoding Initiative 
Telco Telephone Company ("The phone company") 
Telcom Telephone communication 
TELCOR Telecommunications Operating Requirements (USN) 
Telecom Telecommunication 
Teletext Short text messages, usually in TV blank interval 
TELINST Telecommunications Instructions 
Telnet Internet or dialup protocol for remote login 
TEMPEST Telecommunications Electronics Material Protected from Extraneous Spurious Transmissions (secure enclosure for computers, etc.; prevents eavesdropping) 
TEMPO Temporary weather change 
TERPES Technical Electronic Processing and Evaluation System 
TESTM Metar Test Message 
TEU Twenty-foot -----alent Unit, container shipping 
TEXN Traffic Exchange Network (MARS) 
Tfc Traffic 
tfc Traffic 
TFE Tactical field exchange 
TFEO Tactical field exchange officer 
TFN Till Further Notice 
TFR Temporary Flight Restriction 
TFT (1)Thin Film Transistor 
TFT (2)Task Force Terminal 
TFW Tactical Fighter Wing 
THAAD Theater High Altitude Area Defense 
THD Total Harmonic Distortion (audio, in %) 
THFRS Transformation High-Frequency Radio System 
THREATCON Threat Condition (Alpha, Bravo...) 
TIA (1)Telecommunication Industry Association (UK) 
TIA (2)Thanks in advance 
TIA (3)The Internet Adaptor, clever SLIP emulator from dialup shell 
TIBS (1)Tactical Information Broadcast System 
TIBS (2)Telephone Information Briefing Service 
TIDLS Tactical Information Data Link System 
TIFF Tagged Image File Format, versatile computer graphic standard 
TIGER Topologically Integrated Geographic Encoding and Referencing 
TIM Time Intermodulation distortion (audio) 
TIN Taxpayer Identification Number (same as SSN - FCC forms) 
TIP Threat Image Projection 
TIS (1)Traveler's Information Station 
TIS (2)Trusted Information System 
TIS (3)This Is (ALE) 
TISCOM Telecom & Information Systems Command, VA (USCG) 
TKAP Transmitter Keep-Alive Program 
TLA Three-Letter Acronym (NASAspeak for NASAspeak) 
TLD Top Level Domain (.com, .org. .net, etc) 
TMC (1)Technical Materiel Corporation, out of business 
TMC (2)TeleMonteCarlo, Monaco 
TMDE Test, measurement, and diagnostic equipment 
TMMMC Theater medical materiel management center 
tms Teams 
TN ("Tango November") Track number (ASW) 
TN3270 Telnet for IBM mainframes, emulates old 3270 terminal 
TNC (1)Terminal Node Controller (packet) 
TNC (2)Threaded Neill-Concelman (connector) 
TNC (3)Threaded Navy Connector (alternate) 
TOA Time Of Arrival 
TOC Tactical Operations Center 
TOD (1)time of day 
TOD (2)Tactical Ocean Data 
TOD (3)Target Offset Distance 
TOD (4)Takeoff Distance 
TODS TFR Operations Display System (see TFR) 
TOE (1)Table(s) of organization and equipment 
TOE (2)Theory of everything (physics) 
TOR Teleprinting (or Telex) over Radio 
TOW (1)Tube-launched Optically-tracked Wire-guided missile 
TOW (2)Terminal orderwire 
TOW (3)Time Of Week (see GPS) 
TOW (4)Takeoff Weight 
TPC Tropical Prediction Center, Miami, FL 
TPFDD Time-phased force and deployment data 
tpi Turns per inch 
T-Plex 8-frequency duplex ARQ teleprinter system 
TPM Technical Protection Measures 
TPO Transmitter power output 
TPR Third-Party Relay 
TPRAM Triple Port RAM 
TR Transmit-Receive 
TRACAB Terminal RAdar control in the tower CAB 
TRACE Transition Region And Coronal Explorer (NASA) 
TRACON Terminal Radar Approach Control 
TRADOC United States Army Training and Doctrine Command 
trans Transportation 
TRANSCOM Transportation Command 
TRC (1)Tactical Radio Communication 
TRC (2)Transmission Release Code 
TRI-TAC Joint Tactical Communications 
trmt Treatment 
TRSA Terminal Radar Service Area 
TRT Tropical RadioTelegraph, once owned by United Fruit Co 
TRUEX Training in Urban Environment Exercise (USMC) 
TS (1)thunderstorm 
TS (2)Tropical Storm 
TSA Transportation Security Administration 
TSB Technical Support Branch (TPC) 
TSC (1)Tactical Service Center (US Navy) 
TSC (2)TRICARE Service Center (US Navy medical) 
TSC (3)Terrorist Screening Center 
TSC (4)Technical Subcommittee (of IRAC) 
TSC (5)Training Systems Contract 
TSC (6)Training Support Center 
TSCC (1)Tactical Surveillance Control Center (US Navy) 
TSCC (2)Transportation Security Control Center (TSA) 
TSCC (3)Trauma Symptom Checklist for Children 
TSCC (4)Telemetry Standards Control Committee 
TSCC (5)Telemetering Standards Coordination Committee 
TSCC (6)Tracking Signal Corrections Counter 
TSCM Technical surveillance countermeasures (antibugging) 
TSGT Technical Sergeant 
TSNO thunderstorm information not available 
TSOP Thin Small Outline Package 
TSP (1)Telecommunications Support Plan (NCS) 
TSP (2)Telecommunications Service Priority (NCS) 
TSR Terminate and Stay Resident (IBM programming) 
TSSR Tropospheric Scatter (TROPO)-Satellite Support Radio 
TTL (1)Transistor-Transistor Logic 
TTL (2)Time To Live (of Internet packets or DNS records) 
TTL (3)Talk To ya Later 
TTL (4)Through The Lens 
TTP Trusted Third Party (for authentication of public keys) 
TTT CW prefix: Distress call follows 
TTWCS Tactical Tomahawk Weapon Control System 
TTY Teletype 
TTYL Talk (Type) To You Later (Internet) 
TU (1)CW brevity: Thank you 
TU (2)Terminal unit (old current-loop RTTY) 
TUBA TCP and UDP with Bigger Addresses (possible Internet extension) 
TUNES Spanish group callsign: Todos las Unidades y Establecimientos navales 
 (all units and naval establishments) 
TV Television 
TVA Tennessee Valley Authority (big dam operator) 
TVC Televisió de Catalunya (Catelan TV, Barcelona) 
TVI Television interference 
TVNZ Television New Zealand 
TWA (1)Trailing-wire antenna (USN ELF/Tacamo) 
TWA (2)Tilt Whip Adaptor (US Army) 
TWA (3)Trans World Airways 
TWAIN (1)Toolkit Without An Important Name (Standard graphic scanner interface) 
TWAIN (2)Technology Without An Interesting Name 
TWAS This Was (ALE) 
TWEB Transcribed Weather Broadcast 
Twinplex Four-frequency duplex teleprinter system 
TWR (1)tower 
TWR (2)Trans World Radio 
TWT Traveling Wave Tube 
TWX Teletype Wide-area eXchange 
tx Transmitter, talk 
TXD Transmitted Data (Serial I/O modem line) 
txt (1)Extension: file is unformatted ASCII text (computers) 
txt (2)Text 
U CW brevity code: "You" 
U Up 
U/L (1) Uplink 
U/L (2) Upload 
UA (1)Packet control frame: Unnumbered Acknowledgement 
UA (2)User Agent (Internet) 
uA Microamp 
UART Universal Asynchronous Receiver/Transmitter (computer) 
U-ATA Ultra-AT Attachment 
UAV Unmanned Aerial Vehicle (USAF) 
UCVE Unconfined Vapor Cloud Explosion 
UDP User Datagram Protocol, (streaming) 
UDRE User Differential Range Error (GPS) 
UDT (1)Universal Dataflow and Telecommunications 
UDT (2)Underwater Demolition Team, crack USN WWII unit 
UEJ Unattended Expendable Jammer 
uf Microfarad 
UFN Until Further Notice 
UFO (1)Unidentified Flying Object 
UFO (2)UHF Follow On, new Navy COMSAT 
UGR Unitized group ration 
UHF Ultra High Frequency (300-3000 MHz) 
UI (1)User Interface 
UI (2)Packet designator: Unnumbered Information 
UI (3)User Initiated 
UICC Universal Integrated Circuit Card 
UID User Identification 
UIDL User Initiated Download 
UIN Universal Internet Number (ICQ) 
UK United Kingdom 
UKADGE UK Air Defense Ground Environment 
UKCC United Kingdom Control Center 
UKMACCS United Kingdom Maritime Coastal Communications System 
UKMET United Kingdom Office of Meteorology (also a model) 
UKNET UK network for UUCP 
UKSOF UK Satellite operations facility, part of NATO 
UL (1)Upload 
UL (2)Unauthorized launch 
UL (3)Underwriters' Laboratories 
ULS Universal Licensing System (FCC) 
UMT Unit ministry team 
UMTS Universal Mobile Telecommunications System 
UN United Nations 
UNB Universal Magnetic Balun 
uncl unclassified 
UNCLASS Message is not classified [~] 
UNCLOS United Nations Convention on the Law of the Sea 
UNF (1) UN Forces 
UNF (2) Unformatted 
UNHCR UN High Commission for Refugees 
UNI User Network Interface 
Unid Unidentified 
Uniden Unidentified 
UNIFIL UN Interim Forces, Lebanon 
Univac Universal Automatic Computer, once IBM's main competition 
Unix Not an acronym; computer op-system derived from MULTICS [~] 
Unk Unknown 
UNO United Nations Organization 
UNPROFOR UN Provisional Forces 
UNSCOM UN Special Commission (Iraq inspectors) 
UP (1)CW prosign: "change to working frequency" 
UP (2)unknown precipitation 
UPNP Universal Plug aNd Play 
UPS (1)Uninterruptible Power Supply 
UPS (2)United Parcel Service 
UR CW brevity code: "Your" 
URE Unión de Radioaficionados Españoles 
Ureq User request (computer return code) 
URL Universal Resource Locator (World Wide Web) 
URSI International Union of Radio Science 
URSIGRAM Coded solar-terrestrial report, originally from URSI 
US (1)United States 
US (2)Unit Separator (ASCII) 
USA (1)United States of America 
USA (2)US Army 
USA (3)Underground Service Alert ("dial before you dig") 
USA (4)Unit self-assessment 
USACE US Army Corps of Engineers 
USADA US Department of the Army 
USAF US Air Force 
USAFA US Air Force Academy 
USAFAWC US Air Force Air Warfare Center 
USAFE US Air Forces, Europe 
USAIS US Army Intelligence and Security Command, VA 
USAMMA US Army Medical Materiel Agency 
USAR (1)Urban Search & Rescue 
USAR (2)US Army Reserve 
USAREUR US Army, Europe 
USARSPACE US Army Space Command, part of USSPACECOM 
USART Universal Synchronous/Asynchronous Receiver/Transmitter 
USASC US Army Signal Command 
USASCH US Army Support Command Hawaii 
USASDC U.S. Army Strategic Defense Command, now USASSDC 
USASI US Army Space Institute 
USASSDC US Army Space and Strategic Defense Command, formerly USASDC 
USAV US Army Vessel 
USAWC US Army War College 
USB (1)Upper Sideband 
USB (2)Universal Serial Bus 
USC (1)United States Codes (Federal statute law) 
USC (2)Unified Space Command, now USSPACECOM 
USC (3)Up S[pit] Creek 
USCENTCOM US Central Command 
USCG US Coast Guard 
USCGA US Coast Guard Auxiliary 
USCGC US Coast Guard Cutter 
USCGR US Coast Guard Reserve 
USCS US Customs Service 
USCSIS United States Space Command Space Intelligence System 
USD US Dollars 
USDA US Department of Agriculture 
USELMNORAD US element, North American Aerospace Defense Command 
USENET "User Network," huge volunteer organization that propagates "News," not necessarily over Internet 
USEUCOM US European Command 
USFJ US Forces, Japan 
USFS US Forest Service 
USFWS US Fish and Wildlife Service 
USG (1)US Gallons (about 4 liters) 
USG (2)US Government 
USGS (1)US Coast & Geodetic Survey 
USGS (2)US Geological Survey 
USIA US Information Agency 
USKA Union Schweizerischer Kurzwellen-Amateure (Swiss ham assn) 
USLANTCOM US Atlantic Command 
USM US Marshal 
USMA US Military Academy 
USMC US Marine Corps 
USMCR US Marine Corps Reserve 
USMS US Marshals Service 
USMTF United States Message Text Format 
USN US Navy 
USNA US Naval Academy 
USNG US National Guard 
USNO US Naval Observatory 
USNR (1) US Naval Reserve 
USNR (2) US Navy, Retired 
USNS US Naval Ship 
USO United Service Organizations 
USOS Unshift On Space 
USP University of the South Pacific (Fiji, classes by radio) 
USPACOM United States Pacific Command 
USPHS United States Public Health Service 
USPS (1)United States Postal Service 
USPS (2)US Power Squadrons 
USR (1)User 
USR (2)US Robotics (modem mfgr) 
USS United States Ship 
USSOCOM US Special Operations Command 
USSOUTHCOM U.S. Southern Command 
USSPACECOM U.S. Space Command 
USSS United States Secret Service 
USSTRATCOM U.S. Strategic Command 
USTA United States Total Army 
USTRANSCOM United States Transportation Command 
USVI US Virgin Islands 
UT (UT0 - UT3) Universal Time scales (corrected constantly) 
UTB Utility Boat 
UTC (1)Universal Time, Co-ordinated (corrected with leap sec.) 
UTC (2)Coordinated Universal Time 
uTLD Unsponsored Top Level Domain (.biz, etc) 
UTP Unshielded Twisted Pair (hardwired networks) 
UUCP Unix-to-Unix Copy Program (Unix file transfer s/w) 
Uudecode Unix program, converts uuencoded files back to binaries 
Uuencode Unix program, converts binary files to ASCII for transfer 
uuf Micro-microfarad, now pf (picofarad) 
uV Microvolt 
UV Ultraviolet 
uW Microwatt 
UWB Ultra Wideband 
UWC Universal Wireless Communications consortium 
UXB Unexploded Bomb 
UXO Unexploded Ordnance 
V (1)Voltage (electromotive force) 
V (2)Variable 
V (3)Verification 
v Velocity 
VA (1) CW prosign: "End of transmission" 
VA (2) Volt-amps (as in a power supply) 
VA (3) Veteran's Administration 
VA volcanic ash 
VAAA Voice Activated Auto Attendant (telco) 
VAAT Voice Activated Audio Text (telco) 
VAB Vehicle Assembly Building (NASA) 
VABP Voice Activated Blue Pages (telco) 
VAC Volts Alternating Current 
VAD Voice-Activated Dialing (telco) 
VADM Vice-Admiral 
VAFB Vandenberg Air Force Base (CA) 
VAIVR Voice Activated Interactive Voice Response (telco) 
VAL Visiting Aircraft Line 
VANC Voice-Activated Network Control (telco) 
VAPD Voice Activated Premier Dialing (telco) 
VAS VOLMET Automation System 
VASI Visual Approach Slope Indicator 
VAX (1)Variable Address Extension (old DEC Computer) 
VAX (2)English vacuum cleaner brand : ) 
VAX/VMS VAX Virtual Memory System, op-system for above 
VBI Vertical Blanking Interval (TV) 
vBNS Very high speed Backbone service (US) 
VBR Variable Bit Rate 
VBS Visual Basic Scripting (Microsoft security nightmare) 
VC in the vicinity 
Vcc Collector voltage 
VDC Volts Direct Current 
VDE Video Display Editor, at one time standard freeware CP/M & PC text editor 
VDL VHF Data Link (ARINC) 
VDLM2 VDL, Mode 2 
VDLC Virtual Data Link Capability 
VDSL Very high-data-rate Digital Subscriber Line 
VDSL Very-high-bit-rate Digital Subscriber Line 
VDT Video Display Terminal 
VDU Video Display Unit 
VE Volunteer Examiner (Amateur) 
VEC Volunteer Examiner Coordinator (Amateur) 
VENONA Old US codeword for its USSR decryption program 1943-1980 [~] 
VESA Video Equipment Standards Association, computer displays 
VESREP Standard report from commercial fishing vessel 
VEUR European Volmet 
VF (1)Voice frequency 
VF (2)Velocity Factor 
VF (3)Fighter squadron (USN) 
VFAT Virtual File Allocation Table (MS-Windows) 
VFO Variable Frequency Oscillator 
VFR Visual Flight Rules 
VFT Voice Frequency Telegraph (multiplex RTTY) 
VHF Very High Frequency (30-300 MHz) 
vi Visual Editor, full-screen text editor for Unix 
VICS Vehicle Information Communication System 
VIN Vehicle Identification Number 
VIP Very Important Person 
VIS visibility 
VISNO visibility at secondary location not available 
VLB VESA Local Bus; PC display bus, now usually done by the PCI 
VLF Very Low Frequency (3-30 kHz) 
VLM Virtual Loadable Module (Novell) 
VM (1)Voice mirror 
VM (2)Virtual memory 
VMC Visual Meteorological Conditions 
VMS Virtual Memory System, good but obsolete DEC OS 
VNA Viet Nam News Agency 
Vne Absolute top speed of an aircraft; "never exceed" 
VOA Voice Of America 
Vocoder Voice coder 
VOH Voice Of Hope (KVOH, religious broadcaster) 
VOIP Voice Over Internet Protocol 
VOLMET Flight weather transmission, for planes in route 
Volt Unit of electrical potential, named for Alessandro Volta 
VOM Volt-Ohm Meter 
VOMUX Voice Multiplexer 
VOR (1)VHF Omnidirectional Ranging (Aircraft NAVAID) 
VOR (2)Voice Of Russia 
VORTAC Ground station combining VOR and TACAN 
VOX Voice operated switching 
VPF Vertical Processing Facility (NASA) 
VPN Virtual Private Network 
VR (1)Voltage regulator 
VR (2)Visual Route (air training route) 
VRAM Video RAM 
VRB Variable wind 
VRC (1)Vehicular Radio Communications (AN/VRC-xxx) 
VRC (2)Vehicular radio configuration (Army) 
VRC (3)Vertical Redundancy Check, fancy name for parity (computers) 
VRML Virtual Reality Modeling Language 
VROC Vertical rate of climb 
VRT Vlaamse Radio- en Televiseomroep (Belgian) 
VSAT Very Small Aperture (Antenna) Terminal 
VSC Vertical Service Code (telco features - start with *) 
VSFC Virginia Space Flight Center, Wallops Island 
vsh Visual Shell, clunky full-screen command interpreter for Unix 
VSWR Voltage standing wave ratio 
VT (1)Vertical Tab (ASCII) 
VT (2)Valid Time (wx forecasts) 
VTnnn Series of old DEC terminals, still a popular emulation code 
VTP Virtual Terminal Protocol 
VTS Vessel Traffic Services 
VTVM Vacuum-tube voltmeter 
VU Volume Units 
VUFER VHF/UHF Frequency Experimental Radio 
VV Vertical Visibility (of obscured sky) 
VVV CW test group 
VWS Virtual Warning System 
VxD Virtual Device Driver (MS-Windows) 
VXO Variable Crystal Oscillator 
VY CW brevity code: "Very" 
W Power, in watts 
W west 
W Whisky ("Benchmark Whisky" is USN offset) 
W3C World Wide Web Consortium 
WA (1)CW prosign: word after 
WA (2)Work Authority (railroad orders) 
WABNRES Worldwide Airborne Resources (command a/c) 
WAC (1)Worked All Continents (amateur award) 
WAC (2)Women's Army Corps, obsolete 
WAC (3)World Aeronautical Chart 
WAD Wide-Area Domain (computer games) 
WAFS World Area Forecast System, satellite delivered air wx 
WAGB USCG designation for icebreaker 
WAIS Wide-Area Information Server 
WAMS Wide Area Master Station 
WAN (1)Wide-Area Network 
WAN (2)Wide-Area Network Station 
WAP (1)Wireless Application Protocol 
WAP (2)Wireless Access Point 
WARC World Administrative Radio Conference 
WARN Weather Amateur Radio Network, see SKYWARN 
WARP Weather and Radar Processor 
WAS (1)Wide-Area Surveillance 
WAS (2)Worked All States (US amateur award) 
WAS/MTI Wide Area Surveillance/Moving Target Identification 
WATS Wide Area Telephone Service 
WAZ Worked All Zones (amateur award) 
WB (1)Wideband 
WB (2)CW prosign: word before 
WB (3)Welcome Back (Internet) 
WB (4)Warner Bros (Good movie studio, lousy TV network) 
WBFM Wideband frequency modulation 
WBU World Broadcasting Unions 
WBU-ISOG WBU Inter-Union Satellite Operations Group 
WBU-TC World Broadcasting Unions Training Centers 
WCRP (1)World Climate Research Program 
WCS (1)Wireless Communications Service 
WCS (2)Waste Collection System (Space shuttle potty) 
WDC World Data Center, any of several for solar-terrestrial obs 
W-DCMA Wideband Code Division Multiple Access 
WE Western Electric 
WEFAX Weather Facsimile 
WEMA Work Equipment Movement Authority (railroad orders) 
WEMF World Electronic Media Forum 
WEP Wired -----alent Privacy (wireless computer LANs) 
WFAS Wildland Fire Assessment System (USFS) 
WFM Wideband FM 
WFN War Fighter Net 
WFO Weather Forecast Office 
WG Working Group (ITU) 
WG/SO Working Group for Surface Observations 
WGI World Geophysical Interval (research observation period) 
WHCA White House Communications Agency 
WHEC High-Endurance Cutter (USCG) 
WHISC Western Hemisphere Institute for Security Cooperation (see SOA) 
whoami Returns name you are logged in under (Unix) [~] 
whois Internet lookup program for finding people by querying servers [~] 
WIE With Immediate Effect 
WIFCOM Wirefree communications (US Navy) 
Wi-Fi Wireless Fidelity, 802.11 standard interface; originally 802.11b 
Wilco Voice prosign: Will comply 
WIMP (1) Window, Icon, Mouse, Pointer (graphical interface) 
WIMP (2) Weakly Interacting Massive Particle 
WINS Windows Internet Naming Service 
WINSOCK Windows Sockets API, used for networking from Microsoft s/w 
WISE Web-Integrated Software metrics Environment 
WIU Wayside Interface Unit (railroad) 
WIX USCG designation for training barque Eagle 
Wkg Working 
WL Wordlength, size of basic data group (computing) 
WLAN Wireless Local Area Network (computing) 
WLB Seagoing Buoy Tender (USCG) 
WLI Inland Buoy Tender (USCG) 
WLIC Inland Construction Tender (USCG) 
WLIS We Love Interval Signals (Pirate) 
WLL wireless local loop 
WLM Coastal Buoy Tender (Medium Endurance USCG vessel) 
WLR River Buoy Tender (USCG) 
WMD (1)Weapons of Mass Destruction 
WMD (2)Weapons of Mass Distraction (psyops tongue-in-cheek) 
WMD-CST Weapons of Mass Destruction Civil Support Team 
WMEC Medium-Endurance Cutter (USCG) 
WMO World Meteorological Organization 
WMR World Music Radio 
WMSCR Weather Message Switching Center Replacement 
WMTS Wireless Medical Telemetry Service 
WMV Windows Media Video 
WND wind 
WNW West-northwest 
WO Work order 
WORM Write-Once Read-Many (CD-R, allows making own CD-ROMs) 
Wouff Hong Scary wooden device supposedly used on posteriors of hams causing QRM (ARRL lore) [~] 
WPA Wi-Fi Protected Access 
WPB Patrol Boat (USCG) 
WPM Words per minute 
WRAPA Work Restricted Authority/Protect Against (railroad orders) 
WRC World Radio (Communications) Conference 
WRCC Western Regional Climate Center (NOAA) 
WRTH World Radio TV Handbook 
WRU Who Are You? (RTTY) 
WSHFT wind shift 
WSL Weapons Survivability Lab 
WSM Weapon system manager 
WSMR White Sands Missile Range (NM) 
WSO Weapon Systems Officer ("Whizzo") 
WSRO Weapon system replacement operations 
WST Weather Station 
WSTF White Sands Test Facility (NM) 
WSW West-southwest 
WT (1)Walkie-talkie 
WT (2)Wireless Telegraph (Morse or RTTY) 
WTB (1)Wireless Telecommunications Bureau (FCC) 
WTB (2)Want To Buy (radio swap ads) 
WTDD Wayside Train Defect Detector (hotbox/dragger detector) 
WTGB 140' Icebreaking Tug (USCG) 
WTLD Wayside Train Length Detector 
WTMD Walk-Through Metal Detector 
WU Western Union 
WUAN Wireless Universe Area Network 
WUN World Utility News, Internet group, maintains large e-mail list, rhymes with "one" 
WVDC Working Voltage, DC (capacitors) 
WW Weather Warning 
WWABNCPP Worldwide Airborne National Command Post Program 
WWCR (1)World Wide Christian Radio (callsign) 
WWCR (2)World Wide Conspiracy Radio (facetious) 
WWMCCS Worldwide Military Command and Control System, obsolescent 
WWNWS World Wide Navigational Warning Service 
WWRB World Wide Religious Broadcasters (callsign) 
WWV NIST standard frequency & time station, Boulder, CO 
WWVB NIST Boulder, CO, low frequency standard broadcast 
WWVH NIST standard frequency & time station, Kekaha, HI 
WWVL Old NBS low-frequency time stn, no longer on air 
WWW World Wide Web, aka W3, www, Web, World Wide Wait 
Wx Weather 
WYFR We're Your Family Radio (Callsign) 
WYSIWYG What You See Is What You Get (computers) 
X (1) Reactance, in ohms 
X (2)(Also "Xray") prosign for end of sentence 
XAML eXtensible Application Markup Language (mickeysoft) 
X-band (1)8-12 GHz microwave band 
X-band (2)Expanded AM band, 1610-1720 kHz 
XCHS Extended Cylinder, Head, Sector (addressing) 
xcvr Transceiver 
xfmr Transformer 
XINU XINU Is Not UNIX (recursive and retrograde) 
xistor Transistor 
xmit Transmit mode 
XML eXtensible Markup Language 
xmlns XML namespace 
XMODEM Async file transfer protocol, uses 128-byte or 1K packets, over direct links, not Internet 
XMPP Extensible Messaging and Presence Protocol 
XMS Expanded Memory System (IBM PC, different spec from EMS) 
xmsn Transmission 
xmt Transmit mode 
xmtr Transmitter 
XO Executive officer 
Xon/Xoff Computer serial flow control, usually using DC3/DC1 (^S/^Q) 
xponder Transponder 
XSD XML Schema Definitions (see XML) 
XSL eXtensible Style Language 
XSS (1)Cross Site Scripting (Computer security) 
XSS (2)eXperimental Satellite System (USAF) 
XSS (3)eXtremely Simple Syndication (news feed) 
XSS (4)Callsign for new UK/NATO ALE system [~] 
XT eXtra Value (PC-XT was first IBM PC with a hard disk; obsolete) 
XTACACS Extended Terminal Access Controller Access Control System (Cisco) 
xtal Crystal 
XTP eXpress Transfer Protocol (computers) 
XUL (1)XML User-interface Language 
XUL (2)eXtensible User-interface Language 
X-windows Standard windowing system for networks (usually Unix) [~] 
XXX (1)CW prefix: traffic is urgent (same as SECURITE) [~] 
XXX (2)Set of standards for X.25 PAD packet networking 
XYL Wife ("ex-young lady") 
Y2K Year 2000, or resulting computer bugs (geekspeak) 
YAHOO Yet Another Heirarchical Officious Oracle; may be a back-formation, as guys who started Yahoo! styled themselves as just yahoos 
YB Yacht Boy (Grundig radio line) 
YF CW brevity code: "Wife," more typically "XYL" (eX-Young Lady) 
YL Female voice ("Young Lady") 
YLE Yleisradio (Finland, not an acronym) 
YMMV Your Mileage May Vary (cardinal rule of HF) 
YMODEM Along with YMODEM-G, improved async file transfer protocol [~] 
Z (1)Zulu time, standard time on 0 meridian, like UT 
Z (2)Impedance (in ohms) 
Z (3)This message has FLASH precedence 
Z-80 Early 8-bit processor chip, used by CP/M, still made 
Z-Count 29-bit binary GPS time stamp (17 LSBs are broadcast) 
ZAA Z-code: You have improper circuit discipline 
ZAE Z-code: I am unable to receive you 
ZAN Z-code: We have absolutely negative copy 
ZBI UK Military Z-code: Switch to voice mode 
ZBO Z-code: (INT ZBO Do you have traffic (of precedence...) for me?) I have traffic (of precedence...) for you 
ZBR Z-code: Break for retuning 
ZBZ Z-code: (INT ZBZ: What is my signal's printing acceptability? (1-5) ) Your signal's printing acceptability is (1-5) 
ZCP Z-code: I have poor conditions; please use full power 
ZCPR3 Small Z-80 operating system, improved on CP/M, obsolete 
ZDE Z-code: Message undelivered 
ZDF Z-code: Message delivered 
ZEN Military Z-code: Message has been copied to... 
ZFD Military Z-code: Message may be a duplicate 
ZFG Military Z-code: Message is a duplicate and is to be forwarded 
ZKI Z-code: Listen [on _ kHz] 
ZKR Z-code: I have a radio watch on _ kHz 
ZNC Z-code: I have no communication with _ 
ZNG Z-code: Band conditions no good for copy 
ZNI Z-code: No station ID heard 
ZNJ Military Z-code: Message has been sent to... 
ZNK Military Z-code: Addressees who do not hold cryptographic facilities are exempted 
ZNR Military Z-code: Msg may be forwarded without change by radio or non-approved circuit 
ZNR UUUUU Security Warning Signal: Message is Unclassified or offline encrypted - OK to forward unchanged on any circuit 
ZNX You have disclosed an EEFI (1-10; see EEFI) 
ZNY Military Z-code: Do not forward this message unencrypted by 
radio or non-approved circuit. 
ZNY RRRRR Security Warning Signal: Message is RESTRICTED 
ZNY CCCCC Security Warning Signal: Message is CONFIDENTIAL 
ZNY SSSSS Security Warning Signal: Message is SECRET 
ZNY TTTTT Security Warning Signal: Message is TOP SECRET 
ZRF Zero Retention Force 
ZRO Z-code: How copy? 
ZSR Z-code: You are strong-readable 
ZUC Z-code: Unable to comply until ---- 
ZUH Z-code: Unable to comply 
ZUT (1)Unofficial Z-code: "CW Forever!" (see CW) 
ZUT (2)Zeta Upsilon Tau, 60s US Coast Guard radio op society 
ZWEI ZWEI Was EINE Initially (recursive acronym; see EINE) 
ZWR Z-code: You are weak-readable 
° degrees 
µ micro 
µµF micro-microfarad, now pF 
µH microhenry 
µV microvolt 
Police/CB 10-codes: 
10-1 Your signals are being received poorly 
10-2 Your signals are loud & clear 
10-3 Stop transmitting 
10-4 Your message is received ("Roger;" saying both is redundant) 
10-5 Please relay 
10-6 Station is busy 
10-7 Out of service, radio off 
10-8 In service, available 
10-9 Please repeat message 
10-10 Out of service, radio on 
10-19 Go back to station/HQ 
10-20 Location ("What's your 20?") 
10-21 Use landline/phone 
10-22 Cancel message 
10-23 Stand by 
10-27 Driver's license ID check 
10-28 Vehicle registration check ("Rolling 28" -CHP) 
10-33 All units stand by, frequency is on emergency status 
10-97 I am arriving at assignment/ on scene ("I'm 97") 
10-98 Assignment completed/ leaving scene 
10-99 Emergency; -----alent to SOS and MAYDAY 
Other police codes: 
Code 1 Come in on the radio 
Code 2 Respond quickly, without lights/siren ("hurry") 
Code 2A Hurry faster - call is priority 
Code 3 Respond with lights/siren 
Code 4 No more help needed, situation stable 
Code 4A No more help needed, suspect still not in custody 
Code 5 Stakeout at (--), uniformed patrol stay away 
Code 6 Out of vehicle, on investigation 
Code 7 Out to lunch 
Code 10 Request clear frequency 
Code 20 Notify news media 
Code 30 Alarm 
Code 30A Alarm with audible suspects inside 
Code 33 Emergency, all units stand by 
Code 37 Vehicle is stolen (LAPD) 
Code Alpha Assemble at prearranged staging point (LAPD) 
Code Blue (1)Notify police 
Code Blue (2)Respiratory emergency (medical) 
Code Red (1)Notify fire department 
Code Red (2)Frequency is restricted (LAPD Metro) 
(your cops might be a bit different) 
Computer networking standards: 
IEEE 1394 "Firewire" high speed data transfer 
56Kflex Telephone modem 56K, falling back in 2K increments from there. 
802 Family of IEEE recommendations for computer networks 
802.3 Ethernet, fast packet transfers, resembles wired radio 
802.3ab Hot-rod Ethernet, one billion bits/sec over long copper 
802.3u Provides auto-speed, autoselection of duplex 
802.3z Hot-rod Ethernet, one billion bits/sec over fiber or twinax 
802.11 Draft standard for wireless Ethernet 
802.11 Original system; 1-2 Mbps using spread spectrum 2.4 GHz 
802.11a 54 Mbps via 5-GHz orthogonal FDM 
802.11b 11 Mbps in 2.4 GHz spread spectrum (Wi-Fi) 
802.11g 20+ Mbps in 2.4 GHz SS 
802.11n Multi-channel on both bands 
802.12 Recommendation for 100BaseVG/ 100VG/ AnyLAN 
10Base-2 IEEE 802.3 thin ethernet (high-speed computer networking) 
10Base-5 IEEE 802.3 thick ethernet 
10Base-F IEEE 802.3 ethernet over fibre-optic cable 
10Base-T IEEE 802.3 ethernet over twisted pair cabling 
1000Base Gigabit ethernet standards 
1000Base-CX Short-haul over copper 
1000Base-LX 1300nm multimode and single-mode fiber according to 802.3z 
1000Base-SX 850nm multimode fiber according to 802.3z 
1000Base-T Long-haul over copper according to 802.3ab 
100Base-T IEEE 802.3 fast ethernet at 100Mbit/s 
100Base-T4 Encoded 100Mbit/s over 4 pairs, obsolescent 
100Base-TX encoded 100Mbit/s over 2 pairs 
100Base-VG see 100VG-AnyLAN 
100Base-X Encoded 100Mbit/s 
100VG-AnyLAN 100Mb/s LAN carrying Ethernet or Token-Ring, obsolescent 
ATM Asynchronous Transfer Mode 
AAL ATM Adaptation Layer 
AAL-1 Synchronous adaptation layer designed for carrying voice trunk lines 
AAL-2 Adaptation layer intended for variable bit rate video, but never really got off the ground and is not offered by vendors 
AAL-3/4 Adaptation layer intended to be used by Frame Relay and SMDS and other delay-insensitive variable rate or bursty data traffic, but mostly now passed over in favour of AAL-5 
AAL-5 'Simple and efficient adaptation layer' for computer networking 
Bell 103 300 bps FSK (US modem tones, see V.21) 
Bell 212A 1200 bps (US modem tones, see V.22) 
T1 Relatively high speed data connection over phone line 
V.nn Prefix for CCITT specs - these are for phone modems 
V.17 Fax modem spec, to 14400 bps 
V.21 aka "Bell 103," the old 300 bps modem spec, makes sound like RTTY 
V.22 aka "Bell 212A," 1200 bps modem spec, slight differences 
V.22bis Above spec extended to 2400 bps 
V.23 1200/75 bps modem spec 
V.24 data link spec - ----- RS232 
V.25bis modem control sequence for international calls, lost out to Hayes 
V.26bis 2400bps half duplex synchronous, used for fax 
V.27ter 4800bps half duplex synchronous, used for fax 
V.28 Data link spec 
V.32 9600/4800bps 
V.32bis 14.4K/12K/9600/7200/4800bps 
V.32 terbo (V.32 bis ter) proprietary modem spec for 19,200 
V.34 33.6K/31.2K/28.8K/26.4K/24K/19.2K/16.8K/14.4Kbps, then like V.32 
V.42 LAPM error control, 1200bps and above 
V.42bis Data compression, 1200bps and above 
V.90 56Kb, falls back like 56Kflex 
V.FC V.Fast Class: unofficial, 19.2Kbps 
X.nn ITU-T (formerly CCITT) recommendations: 
X.PC Async version of X.25 for small computers 
X.10 Proprietary device control by signalling over AC lines 
X.21 balanced data signalling standard, 15 wires 
X.21bis Above, for 25 wires, unbalanced 
X.25 Packet communication protocols (AX.25 is amateur radio) 
X.27 37-pin data interface, adding handshake and flow control 
X.28 Standard interface, terminal to PAD 
X.29 Control packet standard for PAD and remote host, using X.25 
X.3 PAD standard 
X.31 Network security protocol 
X.400 E-mail protocol 
X.413 Definition of message storage and forwarding 
X.419 Defines P3 and P7 protocols 
X.420 Defines interpersonal e-mail 
X.435 Defines control messages 
X.441 Defines voice messages 
X.500 Directory standard 
X.509 Digital security and identification

Paylaşımlar (?) Bu konuya gelen Linkler: http://www.denizcilikfakultesi.com/gmdss-dokumanlari/4965-gmdss-telsiz-telex-kodlari-4000-a.html
Yazan	Geçerli olduğu yerler	Türü	Tarih
GMDSS Telsiz Telex Kodları (4000+) - Denizcilik Fakültesi	Bu Konu	Refback	26 Mart 2012 18:39
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