GMDSS Telsiz Telex Kodları (4000+)

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
PR (1)Puerto Rico
PR (2)Person Reporting (police)
PR 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