Radio Acronyms
                   (Always under construction)
                      By Hugh Stegman  NV6H

At end of file:

Police/CB 10-codes
Other police codes
Computer networking standards

[~] = not an acronym, just looks like one

Radiospeak, techspeak, milspeak, NASAspeak, and compuspeak all
developed for spoken, sent, or stored brevity.  As Larry Van Horn
is always noting, acronyms and abbreviations don't always save all
that much space in written text.  Utility World tries to slog
through all the alphabet soup and write in good old English.

Sometimes we fail.  Decode our lapses thusly:

Acronym	Definition

+FC	Tornado on the ground
//	Parallel transmission (simulcast) on --
///	Cloud layer below observing station
1 LT	first lieutenant
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 ALE	Second generation automatic link establishment
32BDA	32-Bit Disk Access (Windoze)
3F	Three-figure code groups (mixed or all numbers)
3FG	Three-figure code groups
3G ALE	Third generation automatic link establishment
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
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
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
A	Altimeter setting
A Index	24-hour magnetic activity index, lower=better
A&P	Airframe & Powerplant, U.S. aircraft mechanic certificate
a/c	Aircraft
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	Anti-aircraft artillery
AAAS	American Association for the Advancement of Science
AAB	Automatic Answer-Back (RTTY)
AABCP	Advanced airborne command post
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
AAMSS	Arinc Aeronautical Mobile Satellite Service (proposed; would replace much of MWARA)
AARS	Army Amateur Radio System, started 1925, now part of MARS
AAV	Assault Amphibious Vehicle
AB	Air Base
AB	CW prosign: "[repeat] all before"
ABC	(1)Atomic, Biological, Chemical (warfare)
ABC	(2)American Broadcasting Company
ABCA	American, British, Canadian, Australian
ABCC	Airborne battlefield command and control center
ABCCC	Airborne Command Control Center
ABCS	Army Battle Command System
ABM	Anti-Ballistic Missile
ABN	Airborne
ABNCP	Airborne National Command Post
AC	(1)Alternating Current
AC	(2)Active Components (US Army)
AC&I	Acquisition, Construction & Improvement
ACA	Airspace control authority
ACA	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
ACC	(1)Air Combat Command (US)
ACC	(2)Area Communication Center
ACC	altocumulus castellanus
ACCHAN	Allied Command Channel
ACERT	Army Computer Emergency Response Team
ACFT MSHP	aircraft mishap
ACINT	Acoustic intelligence
ACJ	Advisory Circular, Joint
ACK	Positive Acknowledgment (ASCII 06)
ACLS	Automatic Carrier Landing System
ACM	Association for Computing Machinery
ACMI	Air Combat Maneuvering Instrumentation
ACOM	U.S. Atlantic Command
ACP	Allied Communication Publication
ACR	Armored cavalry regiment
ACS	Assistant chief of staff
ACSB	Amplitude Compandored SideBand
ACSL	altocumulus standing lenticular cloud
ACTD	Advanced Concept Technology Demonstration
ACTS	Automated Computer Time Service
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
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	ActiveX Data Objects
ADO	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
ADPSIS	Automated Data Processing Software Inventory System
ADPSO	Automated Data Processing Security Officer
ADPSSO	Automated Data Processing System Security Officer
ADR	CW brevity: address
ADS	Automatic Dependent Surveillance
ADS-B	Automated Dependent Surveillance-Broadcast
ADSL	Assymetric Digital Subscriber Line
Ae	Auroral Electrojet magnetic activity index
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)
AFEPS	ACARS Front-End Processor System (ground computer network)
AFETR	Air Force Eastern Test Range
AFFSA	Air Force Flight Standards Agency
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
AFN	American Forces Network (US broadcast for military)
AFNET	Air Force Integrated Telecommunications Network
AFR	Armed Forces Radio
AFRES	Air Force Reserve (US)
AFRN	Armed Forces Radio Network
AFRTS	Armed Forces Radio & Television Services
AFS	(1)Air Force Station
AFS	(2)Aeronautical Fixed Service
AFSATCOM	Air Force Satellite Communications
AFSK	Audio frequency-shift keying
AFSOC	Air Force Special Operations Command
AFTCO	Air Force Telecommunications Certification Office
AFTN	Aeronautical Fixed Telecommunication Network
AG	Adjutant general
AGC	Automatic gain control
AGE	Aerospace Ground Equipment (pronounced like how old you are; when you replace it you order New Age)
AGL	Above ground level
AGU	American Geophysical Union
AHAMSL	Antenna height above mean sea level
AHF	Adaptive High Frequency
AHMSL	Antenna height above mean sea level
AHP	Army Heliport
AI	Artificial intelligence
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
AIM	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
AIRK	Area interswitch rekey
AIRMET	Air Meteorological Information
AIS	(Universal) Automated Identification System
AJ	Anti-Jam
AkDT	Alaskan Daylight Time, US
AkST	Alaskan Standard Time, US
AL	Approach and landing
ALC	(1)Automatic level control
ALC	(2)Air logistics center
ALCC	Airborne Launch Control Center
ALCE	Airlift Control Element
ALCS	Airborne Launch Control System
ALE	Automatic 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
Alpha + #	Aircraft maintenance status (1 is best)
Alpha Hotel	A-- H--- (also Adam Henry)
ALQA	Active Link Quality Assesment
ALS	Airlift squadron
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
AMC	(1)Air Mobility Command (old Air Force MAC, MATS)
AMC	(2)Army Materiel Command (US)
AMCO	Aircraft maintenance company
AMD	American Micro-Devices (with Cyrix, Intel's competition)
AMD	Automatic Message Display
AME	Amplitude modulation equivalent
AME	Automatic Message Exchange
AMI	Alternate Mark Inversion
AMMCS	Airborne Multimedia Multiservices Communication System
AMP	Antenna Maintenance Program
AMSA	Australian Maritime Safety Agency
AMSAT	Radio Amateur Satellite, Inc.
AMTOR	Amateur Teleprinting Over Radio (Ham SITOR)
AMVER	Automated Mutual Assistance Vessel Rescue System
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
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	Antenna
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
AOE	Airport of Entry
AOI	Area of interest
AOO	Area of operations
AOR	(1)Area of responsibility
AOR	(2)Atlantic Ocean Region (USCG GMDSS)
AOS	Acquisition Of Signal
Ap	Planetary A index of geomagnetic activity
APC	Armored personnel carrier
APCO	Association of Public Safety Communications Officials
APCO 25	New standard for digital public safety radio
API	Application Programming Interface (computers)
APIC	APCO Project 25 Interface Committee
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	Automatic Packet Reporting System, ham vehicle location w/GPS
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-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
ARDF	(1)Automatic 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	Amphibious Ready Group
ARIA	Advanced Range Instrumentation Aircraft
ARIN	American Registry for Internet Numbers
ARINC	Aeronautical Radio, Inc (US radio consortium)
ARISS	Amateur Radio on the International Space Station
ARM	Anti-radiation missile
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")
ARQ-E3	Single channel ARQ teleprinter system
ARQ6-90	Six-character blocks simplex ARQ teleprinter system
ARRL	American Radio Relay League
ARRS	Aerospace Rescue and Recovery Service
ARSA	Airport Radar Service Area
ARSOF	Army special operations forces
ARTCC	Air Route Traffic Control Center
ARW	Air Refueling Wing (USAF/AFRES)
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
ASAP	As Soon As [humanly] Possible; how one handles FLASH traffic
ASAS	All Source Analysis System (US Army)
ASAS-RWS	ASAS Reconfigurable Work Station
ASB	Aviation support battalion
ASC	(1)AUTODIN Switching Center
ASC	(2)Accredited Standards Committee (ANSI)
ASC	(3)American Society of Cameramen (motion picture)
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)
ASEAN	Association of South East Asian Nations (old SEATO)
ASG	Area support group
ASG	Aeronautical Standards Groups
ASIO	Australian Security Intelligence Organisation
ASL	Above Sea Level
ASLAR	Aircraft Surge Launch and Recovery
ASM	Assembler (computer code)
ASM	Analog Switching Module
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
ASOS	Automatic 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
ASR	Automatic Send-Receive
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	Advanced Technology (IBM's original name for its improved PC, now a standard architecture)
ATA	AT Attachment
ATAPI	AT Attachment Packet Interface
ATC	Air Traffic Control
ATCCS	Army Tactical Command & Control System
ATCT	airport traffic control tower
ATDL 1	Army Tactical Data Link 1
ATF	Bureau of Alcohol, Tobacco & Firearms
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
ATOI	Aerial Track Of Interest
ATP	(1)Ammunition transfer point
ATP	(2)Appletalk Transaction Protocol, Mac networking
ATR	Air Transport Rack (standard airplane radio bay)
ATV	(1)Amateur television
ATV	(2)All-Terrain Vehicle
ATV	Amateur (fast-scan) Television
AUI	Attachment Unit Interface, Ethernet
AUSREP	Australian Ship Reporting System
AUTO	Weather observation is from automated station [~]
AUTODIN	Automatic Digital Network (US military)
AUTOVON	Automatic voice network (now DSN as of 1990)
AUV	Autonomous Underwater Vehicle
AUW	All Up Weight (gross)
AVC	Automatic volume control
AVHRR	Advanced Very High Resolution Radiometer
AVIM	Aviation intermediate maintenance
AVL	Automatic Vehicle Locating
AVTR	Airborne Video Tape Recorder
AVUM	Aviation unit maintenance
AWACS	Airborne Warning And Control System
AWGN	Arbitrary White Gaussian Noise
awk	Aho, Weinstein & Kernighan, wrote a Unix script language
AWN	Aviation Weather Network, now on US Air Force Digital Weather Switch
AWOL	Absent without leave
AWOS	Automated Weather Observing System
AWS	Air Weather Service
AX.25	Amateur variant of CCITT X.25 packet radio protocol
B	began
B+	Tube plate voltage (highest in set)
B-ISDN	Broadband ISDN
B/m	Benchmark
B/U	Backup
B8E	Mode: Independent sideband, different voice programs
B9W	Mode: Independent sideband, mixed voice & data modes
BA	Braking action
Bae	British Aerospace
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)
Baud	Computer transmission unit, used to equal one bit per second, commonly exceeds this in complex modulation schemes, i.e. baud rate <> data pump speed
BBC	British Broadcasting Company
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)
BC3	Battle management and command, control and communications
BCA	Broadcast Control Authority
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	Broadcast listener
BCM	Baseline correlation matrix
BCO	(1)Base communications officer
BCO	(2)Base contracting officer
BCO	(3)Broad concept of operations
BCP	Base comprehensive plan
BCS	Broadcast Keying Station
bd	Baud
BDA	(1)Battle damage assessment
BDA	(2)Bermuda (NASA)
BDAR	Battle damage assessment and repair
bde	Brigade
BDU	Battle dress uniform
BEAR	Beam Experiment Aboard Rocket
BEC	Bulk encrypted communications
BEEF	Base Engineering Emergency Force,("Prime BEEF team")
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
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
BG	Brigadier general
BGEN	Brigadier general
BGP	Border Gateway Protocol (TCP/IP)
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
BIH	Bureau International l'Heur, International Time Bureau, coordinates UTC leap seconds
BILS	Ballistic Impact Locator System
Bin	Binary
BIND	Berkeley Internet Name Domain
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
BIPS	(1)Billion Instructions per Second (computing)
BIPS	(2)Backup Impact Prediction System
Bit	(1)BInary digiT, a one or zero, basic digital information unit
BIT	(2)Built-In Test
Bit/s	Bit per second
BITE	Built-In Test Equipment
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	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
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
BMD	Ballistic missile defense
BMDATC	Ballistic missile defense advanced technology 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/SS	Ballistic Missile transporter, storage and shipping
bn	Battalion
BN	CW prosign: repeat between -- and --
BNC	Bayonet Neill-Concelman (cable connector for radios and computers)
BnOC	Battalion Operations Center
BNSC	British National Space Center
BO	Bad Order (inoperative unit writeup)
BOOTP	Bootstrap Protocol (IP addressing)
BOPS	Billion operations per second (computing)
BOQ	Bachelor Officer Quarters
BORAM	Block-Oriented RAM
bot	Robot, typically a network program that does an admin duty
BOT	Beginning of Tape
BP	Bandpass
bps	Bit per second, not necessarily a "baud"
Bps	Bytes per second
BPSK	Biphase Shift Keying
BQ	Beam Quality
BR	Bridgewire resistance
BR	mist
BRAC	Base Realignment And Closure
BRACC	Base Realignment And Closure Commission (US military)
BRB	Be Right Back (Internet)
brdg	bridge
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	(4)aka "Bravo Sierra;" the excrement of bulls
BS	(3)Backspace
BSA	(1)Brigade support area
BSA	(2)Birmingham Small Arms
BSC	Base security council
BSD	Berkeley Software Distribution (Unix type)
BSE	Broadcast Satellite Experiment
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)
BULLDOG BULLSEYE	US Navy HF upgrade, like USAF's SCOPE, but includes DF [~]
BUMCS	Backup Master Control Station (GPS, Gaithersburg, MD)
BURN	1000W UHF aircraft orderwire (US mil; not an acronym, refers to high power)
BVR	Beyond visual range
BW	Bandwidth
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	The speed of light, and radio waves, in a vacuum
C	(6)Center (with reference to runway designation)
C&DH	Communications & Data Handling
C&DP	Communications & Data Processing
C-band	4-8 GHz microwave band
C-cubed	Command Control and Communications
C-SPAN	Cable-Satellite Public Affairs Network (US)
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	cloud-air lightning
CAATS	Canadian Automated Air Traffic System
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
CAE	Computer-aided engineering
CAI	Computer-aided instruction
CAINS	Carrier Aircraft Inertial Navigation System
CAL	Calibrate, calibration
CALS	Computer-aided Acquisition & Logistics 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	Controller Area Network (industrial automation)
CAN	Cancel (ASCII)
CANFORCE	Canadian Forces
CANR	Canadian NORAD Region
CAOC	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)
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, All Hurricanes (NHC)
CARIBROC	Caribbean Regional Operations Center
CARR	Corrective Action Request & Report
CAS	(1)Close Air Support
CAS	(2)Collision Avoidance System
CAS	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
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	Citizen Band Radio (legal or otherwise, around 27 MHz)
CB	cumulonimbus cloud
CB	Cumulonimbus (thundercloud)
CBC	Canadian Broadcasting Company
CBFS	Cesium Beam Frequency Standard
CBM	Central battle management
CBMAM	cumulonimbus mammatus cloud
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
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	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
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
CCIR	International Radio Consultative Committee, now ITU-R
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	Counter-countermeasures
CCMC	Canadian Centre for Maritime Communications
CCP	Console Command Processor, part of CP/M
CCPC	Civil Communications Planning Committee (NATO)
CCSL	cirrocumulus standing lenticular cloud
CCTV	Closed Circuit Television
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)
CD-DA	Compact Disc Digital Audio (format, part of the "Red Book")
CD-I	Compact Disc - Interactive (one format in the "Green Book")
CD-R	Compact Disc - Recordable
CD-ROM	Compact Disc Read Only Memory
CD-ROM XA	CD-ROM eXtended Architecture, extends the "Yellow Book"
CD-RTOS	Compact Disc - Real Time Operating System (CD-I)
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
CDF	(1)Common Data Format
CDF	(2)California Division of Forestry (fire fighters)
CDHF	Central Data Handling Facility
CDIS	Canadian Defence Intelligence Staff
CDM	Chemical Downwind Message (US Army)
CDMA	Code Division Multiple Access
CDNU	Control Display Navigation Unit
CDR	(1)Commander
CDR	(2)Command destruct receiver (Stratcom)
CDRAM	Cache Dynamic Random Access Memory
CDS	Canadian Defence Staff
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	Commission of the European Communities (drafts "CE" standards)
CEC	Cooperative Engagement Capability
CECOM	US Army Communications Electronics Command
CENTCOM	U.S. Central Command
CEOI	Communications-Electronics Operation Instructions
CEP	Central East Pacific (MWARA)
CEPPO	Chemical Emergency Preparedness and Prevention Office
CEPT	Conference of Postal & Telecommunications Administrations (EU)
CEPTAG	Civil Emergency Planning Telecommunications Advisory Group (Joint US/Canadian)
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	Code of Federal Regulations
CFR	33: USCG Navigation Regulations
CFR	46: USCG Vessel Regulations
CFR	47: FCC Regulations
CFS	Canadian Forces Station
CFT	Center Frequency Tone
CG	(1)Coast Guard
CG	(2)Commanding General
CG	cloud-ground lightning
CGAS	Coast Guard Air Station
CGDN	Coast Guard Data Net
CGM	Corrected Geomagnetic coordinates
CGMS	Coordinating Group for Meteorological Satellites
CGU	Canadian Geophysical Union
Ch	Channel
Ch mkr	Channel marker
CHAP	Challenge Handshake Authentication Protocol (PPP)
CHI	cloud-height indicator
CHINO	sky condition at secondary location not available
CHOP	Chief Operator (Navy MARS)
CHS	Combat health support
CHS	Cylinder, Head, Sector (direct disk addressing)
CI-V	Radio computer interface made by Icom
CIA	Central Intelligence Agency (US)
CIC	(1) Combat Information Center (Navy)
CIC	(2) Combined Intelligence Center (US Air Force)
CICS	Customer Information Control System (IBM)
CIG	ceiling
CINC	Commander In Chief, also can be prepended, as in:
CINCLANT	C in C, Atlantic
CINCPAC	C in C, Pacific
CINCSTRAT	C in C, Stratcom
CIRC	Cross Interleaved Reed Solomon Code
CIS	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
CIW	Combined Intelligence Watch
CIWS	Close-In Weapons System
CJCS	Chairman, Joint Chiefs of Staff (US)
CJFET	Complementary junction field effect transistor
CJMAO	Central Joint Mortuary Affairs Office
CK	Check (usually word count in a message)
CL	CW prosign: I am closing my station (clearing)
CL	Centerline Lighting System
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
CLOVER	Robust RTTY mode for HF
CLR	Clear
CLR	Clear below 12,000 feet (automated METAR)
cm	Centimeter
CM	(1)Countermeasures
CM	(2)Corrected Geomagnetic coordinates
CMARS	Cruise Missile Autonomous Routing System
CMAS	Cheyenne Mountain Air Station, was CMAFB, CMAFS
CMC	(1)Cheyenne Mountain Complex (NORAD)
CMC	(2)Command management center
CMC	(3)COMSAT Mobile Corporation, part of COMSAT
CMD	(1)Command
CMD	(2)Network Command (ALE)
CMDR	Commander
CME	Coronal Mass Ejection, causes aurora
CMI	Computer-managed instruction
CMIS	Cheyenne Mountain Interface Subsystem
CMO	Civil-military operations
CMOS	Complementary Metallic Oxide Semiconductor
CMS	(1)Canadian Maritime Service
CMS	(2)Calendar Messaging Service (Solaris)
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
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)
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
CNRADL	Canadian RADIL (ROCC/AWACS digital information link)
CNS	(1)Communications, navigation & surveillance
CNS	(2)Central nervous system
CNS	Consolidated NOTAM System (Another nested acronym courtesy FAA)
CNTRA	Chief of Naval Air Training (pronounced "Sinatra" like the singer)
co	UK version of .com (Internet domain)
CO	(1)Commanding Officer
CO	(2)Central Office (telcom)
CO/MIS	Commander, Management Information Center
COA	Course of action
Coax	Coaxial cable
COBOL	Common Business Oriented Language (clunky old programming code)
COBRA	(1)Coastal Battlefield Reconnaissance System
COBRA	(2)Counter Battery Radar
COBRA DANE	US military air surveillance radar system
COCOM	Combatant command
CODAR	Coastal Ocean Dynamics Radar
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)
CofS	Chief of Staff
COG	Continuity Of Government (emergency plan)
COL	Colonel
COM	(1)Computer file extension: load as simple command program
COM	(2)Commercial domain (Internet)
COM	Component Object Module (Windoze)
COMACC	Commander, Air Combat Command
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 (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
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
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
COR	(1)Carrier operated relay
COR	(2)Consolidated Operations Room ("Lights Out")
COR	Correction to a previously disseminated weather report
CORES	Commission Registration System (FCC)
COSCOM	Corps support command
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/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.
CPAS	Cellular Priority Access Service
CPCA	Camp Parks Communications Annex (USAF)
CPE	Customer Premise Equipment (telco)
CPFSK	Continuous-Phase Frequency Shift Keying
CPO	Chief Petty Officer
CPR	Cardio-pulmonary resuscitation
cps	Cycle per second (one Hertz)
CPS	(2)Cellular Priority Services (US NCS)
CPS	(1)Characters Per Second
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
CRC	(1)Cyclic Redundancy Check (computer error test)
CRC	(2)CONUS Replacement Center
CREN	Corporation for Research and Educational Networking
CRIS	Communications Resource Information Sharing (US NCS)
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)
CSAR	Combat Search And Rescue
CSB	Corps support battalion
CSC	Combat stress control
CSEL	Combat Survivor Evader Locator (pilot survival radio)
CSG	Corps support group
csh	C-shell, popular Unix command interpreter
CSH	Combat support hospital
CSMA/CD	Carrier Sense Multiple Access/ Collision Detection
CSS	(1)Combat service support
CSS	(2)Central Security Service (US SIGINT, run by NSA director)
CSS	(3)Cascading Style Sheets
CSSCS	Combat Service Support Control System
CST	(1)Central (US) Standard Time
CST	(2)Caribbean Support Tender
CT	("Charlie Tango") - Communications Technician (on an aircraft)
CTA	Control Area
CTAF	Common Traffic Advisory Frequency
CTCSS	Continuous Tone Coded Squelch System ("PL")
CTI	Computer - Telephone Integration
CTIA	Cellular Telecommunications Industry Assn
CTLZ	Control Zone
Ctrl	(1)Control
Ctrl	(2)Computer's control key, sometimes shown with a ^
CTS	Clear To Send (Serial I/O handshaking line)
CU	CW brevity code: "See you"
CUAGN	CW brevity code: "See you again"
CUCV	commercial utility cargo vehicle
CUL	CW brevity code: "See you later"
CV	USN Aircraft Carrier
CVN	US nuclear aircraft carrier
CW	(1)Continuous Wave (usually Morse code)
CW	(2)Clockwise (rotation)
CWIS	Campus-Wide Information System
CWISP	Campus-Wide Information System Protocol
CWP	Central West Pacific (MWARA)
CZ	(Panama) Canal Zone
D	Down
D/L	(1)Downlink
D/L	(2)Download
DA	(1)Directional antenna
DA	(2)Department of the Army
DA-2	Station changes directional pattern at night (FCC)
DAC	(1)Digital-to-Analog Converter
DAC	(2)Disaster Assistance Center (FEMA)
dah	Morse code dash [~]
DAMA	Demand Assigned Multiple Access
DAMSON	Doppler And Multipath Sounding Network
DARN	(1)Dual Auroral Radar Network
DARN	(2)Disaster Amateur Radio Network, SoCal 440 MHz system
DARPA	Defense Advanced Research Projects Agency
DAS	Data Aquisition System
DASR	Digital Airport Surveillance Radar
DAT	Digital audio tape
DB	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
dBd	Decibel gain over dipole antenna
dBi	Decibel gain over (theoretical) isotropic antenna
dBm	Decibels over 1 mW into 50 ohms, usually rf, 0 dBm = 0.316 Vp
DBM	(1)Doubly balanced mixer
DBM	(2)Data Block Message
DBMS	Data Base Management System
DBPSK	Differential Binary Phase-Shift Keying
DBS	Direct broadcasting satellite
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)
DCD	Data Carrier Detect (packet modems)
DCE	Data Communication Equipment (like a modem)
DCG	Deputy commanding general
DCOM	Distributed Component Object Module (Windoze)
DCP	Data Collection Platform
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
DCT	Direct Cosine Transform
DCTN	Defense Commercial Telecommunications Network
DD	Dual Diversity
DDD	Maritime preamble for relayed distress message
DDN	Defense Data Network
DDO	Dynamic Drive Overlay (used by Disk Manager on the PC)
DDR	Dual Diversity Receiver
DDT	Dynamic Debugging Tool, named for old pesticide
DE	Morse code prosign meaning "from"
DE-QPSK	Differentially Encoded Quaternary Phase Shift Keying
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
DES	Data Encryption Standard
DES-FED	Stronger (108 bit) DES used by US government
Det	Detector
DEW	Distant Early Warning (radar in Canada)
DF	(1) Direction finding
DF	(2) Direction finder ("duffer")
DFAS	Defense Finance and Accounting Service
DFO	Disaster Field Office
DGM	Digital group multiplexer
DGPS-MSK	Differential GPS, Minimum Shift Keying
DGPS-QPSK	DGPS-QPSK : Differential GPS, Quarternary Phase Shift
Differential GPS, Quarternary Phase Shift Keying
DHCP	Dynamic Host Configuration Protocol
DHTML	Dynamic Hypertext Markup Language (web)
DIA	Defense Intelligence Agency
DIG	Domain Internet Groper
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
DIP	Dual In-line Package (chips or small switches)
Diplo	Diplomatic traffic, usually encrypted
DIS	Defense Investigative Service
DISA	Defense Information Systems Agency
DISAC	Defense Information Systems Agency Circular
DISC	Packet control frame: Disconnect
DISCO	Defense Industrial Security Clearance Office
DISCOM	Division support command
DISN	Defense Information Systems Network
dit	Morse code dot [~]
DIW	Dead in the water
DL	(1)Download
DL	(2)Data Link
DL	(3)Driver's License (police)
DLA	Defense Logistics Agency
DLE	Data Link Escape (ASCII)
DLL	Dynamically Linked Library (computer programs)
DLRP	Data Link Reference Point, a USN authenticator
DM	Packet control frame: Disconnect Mode (busy)
DM	Delay Modulation (Miller Coding)
DMA	(1)Direct Memory Access
DMA	(2)Defense Mapping Agency
DMAHTC	DMA Hydrographic Topographic Center
DMC	Defence Management Committee (Canada)
DME	Distance Measuring Equipment (at airports)
DMI	Depot Maintenance Interservicing
DMSP	Distributed Mail System Protocol
DMSP	Defense Meteorological Satellite Program
DMT	Discrete Multi-Tone
DMUX	Demultiplexer
DMZ	Demilitarized Zone (Korea)
DN	(1)Dutch (Royal) Navy
DN	(2)Directory Number (telco)
DND	Department of National Defence (Canada)
DNS	Domain Naming System/Server (Internet)
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)
DOD	Department of Defense
DoDD	Department of Defense Directive
DODISS	Department of Defense Index of Specifications and Standards
DoDSI	Department of Defense Security Institute
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)
DPG	Defense Planning Guidance
DPSK	Differential Phase-Shift Keying
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
DRFMU	Digital Radio Frequency Memory Unit
DRSN	Defense RED Switch Network
DS	Direct support
DS	Dust storm
DSA	Division support area
DSB	Double sideband
DSC	Digital Selective Calling (GMDSS)
DSL	Digital Subscriber Line
DSLAM	Digital Subscriber Line Access Multiplexer
DSM	Digital Switching Module
DSN	Defense Switched Network (old AUTOVON)
DSNT	distant
DSOR	Depot Source of Repair
DSP	Digital signal processing
DSR	Data Set Ready (Serial I/O primary handshaking line)
DSS	Digital Satellite System
Dst	Disturbance Storm Time, equatorial magnetospheric activity index
DSTO	Defence Science & Technology Organisation (Australia)
DSVD	Digital Simultaneous Voice and Data
DSW	Russian CW brevity code: "Daswedanya" (Goodbye)
DT	(1)District T (USCG)
DTAC	Division tactical command post
DTE	Data Terminal Equipment (computers, workstations, dumb terminals)
DTG	Date time group (typically ddhhmm mon yy tz)
DTM	Data Text Message
DTMF	Dual Tone Multi Frequency (like telco "touch tone")
DTMF-RA	Dual Tone Multi-Frequency - Remote Access
DTO	Division tactical operations center
DTR	Data Terminal Ready (Serial I/O primary handshaking line)
DTS	Data Terminal Set
DU	widespread dust
DUP-ARQ	Hungarian diplomatic teleprinting system
DUPE	CW prosign: message or contact is a duplicate
DUT1	UTC correction interval to get UT1
DV	Distinguished Visitor
DVA	Department of Veterans Administration
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
E	(1)Electromotive force (in volts)
E	(2)east, ended
E-HA	Enroute High Altitude
E-LA	Enroute Low Altitude
E-mail	Electronic mail, usually by computer
EA	(1)East Asia (MWARA)
EA	(2)Electronic Attack
EAC	Echelons above corps
EAD	Echelons above division
EAF	Expeditionary Airfields
EAM	Emergency Action Message
EARN	European Academic and Research Network
EAS	(1)Emergency Alerting System, replaced EBS
EAS	(2)Equivalent 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
ECB	Echelons corps and below
ECC	(1)Error Correction Code (better than parity)
ECC	(3)Error Control Coding
ECC	(2)Error Checking & Correcting (memory chip)
ECCM	Electronic counter-countermeasures (usually freq hopping)
ECHS	Extended Cylinder, Head, Sector (addressing)
ECM	Electronic countermeasures
ECOM	Emergency Communications
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
EDI	Electronic Document Interchange
EDO	Extended Data Output (memory chip)
EDP	Electronic Data Processing
EDPT	Enhanced (fixed) Disk Parameter Table
EDR	Enhanced Data Rate
EDT	Eastern (US) Daylight Time
edu	Educational Institution domain (Internet)
EE	(1) Transmission is in English
EE	(2) Person with Electrical Engineering degree
EEC	European Economic Community
EECEN	Electronics Engineering Center, NJ (USCG)
EEFI	Essential elements of friendly information
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")
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
EGS	European Geophysical Society
EI-232	Latest name for RS-232, the serial interface standard
EIA	(1)Electronic Industries Association, replaced RETMA
EIA	(2)Equatorial Ionization Anomaly
EIDE	Enhanced Integrated Drive Electronics, ATA version once proprietary to WD
EIRP	Equivalent Isotropically Radiated Power
EISA	Extended Industry Standard Architecture
EISCAT	European Incoherent Scatter Radar (research)
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
EM	(1)Electromagnetic
EM	(2)Extended mission
EM	(3)Emergency management
EM	End of Medium (ASCII)
Emacs	Editing Macros, powerful if ungainly Unix text editor
EMC	Electromagnetic compatibility
EMCON	(1)Electromagnetic Radiation Control
EMCON	(2)Emission Control (radio, etc, not smog)
EMF	Electromotive force (back-EMF occurs in coils & motors)
EMI	Electromagnetic incompatibility
EMP	Electromagnetic pulse
EMS	(1)Extended Memory Specification (IBM PC, old LIM spec)
EMS	(2)Emergency Medical Services
EMT	Emergency Medical Technician, public safety certificate
ENE	East-northeast
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?)
EOB	Electronic Order of Battle
EOC	Emergency Operations Center
EOD	Explosive Ordnance Disposal, the bomb squad
EOL	End of (design) life
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
EPLRS	Enhanced Position Location Reporting System
EPROM	Electrically Programmable Read-Only Memory
EPS	GOES Energetic Particle Sensor, measures solar flares
EPS	Emergency Planning Subcommittee
EPW	Enemy prisoner of war
ER	Emergency room
ERFAK	Emergency Response Fly-Away Kit (US Govt)
ERLink	Emergency Response Link (US Govt)
erp	Effective radiated power
ERTS	Earth Rotation Time Service, keeps track of planet's actual position in space
ES	(1)Electronic Support
ES	(2)CW brevity code: "And"
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)
ESMC	Eastern Space & Missile Center
ESMTP	Extended Simple Mail Transfer Protocol (does this mean it's no longer simple?)
ESN	Electronic Serial Number
ESS	Electronic Switching System (landlines)
EST	Eastern (US) Standard Time
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	Estimated time of departure
ETLA	Extended Three-Letter Acronym (a four-letter acronym)
ETOH	Alcohol (for some reason, paramedics say the chemical name)
ETX	End Of Text (ASCII)
Eunet	European part of UUCP, Unix file transfer network
EUR	Europe (MWARA)
EUV	Extreme ultraviolet (can ionize)
EW	Electronic warfare
EWO	Emergency War Order
EXE	Computer file extension: loads as executable
EXE2BIN	PC program for creating .COM files from .EXE
f	Farad (a huge capacitor; usually uf or pf)
F	Frequency (in Hertz)
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
FAADC3	Forward Area Air Defense Command, Control, Communications Intelligence System (US Army)
FAC	Field-Aligned Current, an irregular propagation mode
FACSFAC	Fleet Area Control & Surveillance Facility (US Navy)
FAF	French Air Force
FAGDS	Federation of Astronomical and Geophysical Data Services
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
FAS	(3)Frequency Assignment Subcommittee
FASC	Forward area signal center
FAST	Fleet Antiterrorist Strike Team (US Marines)
FAST	NASA Fast Auroral Snapshot Small Explorer satellite
FAT	File Allocation Table (MS-DOS)
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)
FD	Fixed Disk
FD	(1)Floppy Disk
FD	(2)Fixed Disk (confusing!)
FDD	Floppy Disk Drive
FDDI	Fibre Data Distribution Interface
FDM	Frequency-Division Multiplex
FDPT	Fixed Disk Parameter Table
FDX	Full Duplex
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
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
FF	(2)French Forces
FF	Form Feed (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
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 follow
FIGS	Figures case (Baudot upper case)
FIRESCOPE	Firefighting Resources of Southern California Organized for Potential Emergencies
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
FIST	Fleet Imagery Support Terminal (US Navy)
FL	Flight level
FLAK	German: FLeigerAbwehrKannonen (anti-aircraft artillery)
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	(1)flight
Flt	(2)fleet (US Navy)
FLT HICOM	Fleet High Command, (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
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)
FOB	(1)Field Operations Bureau (FCC)
FOB	(2)Freight On Board (shipping regs)
FOD	Foreign Object Damage
FOIA	Freedom of Information Act
FORSCOM	Forces Command
FORTRAN	Formula Translator (early IBM computer language)
FOT	Optimum Traffic Frequency (fq that will work most days of period)
Foxes	THE QUICK BROWN FOX... test [~]
FPM	Fast Page Mode
FPO	Fleet Post Office
Fq	Frequency
FQDN	Fully Qualified Domain Name (Internet)
FR	(1)Frequency Response
FR	(2)Final report
FRA	(1)Forward repair activities
FRA	(2)Federal Request for Assistance (FEMA)
FRCM	Federal Regional Coordinating Manager (FEMA)
Freq	Frequency
FRMR	Packet control frame: Frame Reject
FRN	FCC Registration Number
FROPA	frontal passage
FRP	Federal Response Plan (FEMA)
FRQ	frequent
FRS	Family Radio Service
FS	File Separator (ASCII)
FSB	Forward support battalion
FSBS	(Consolidated) Fixed Submarine Broadcast System
FSC	Full Scope Command (USAF HF Phase II)
FSE	Fire support element
FSF	Free Software Foundation
FSK	Frequency-shift keying
FSL	Forecast Systems Laboratory
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
FST	Forward surgical team
FSTS	Federal Secure Telecommunications System
ft	foot
FT	(1)Terminal Forecast (weather)
FT	(2)Feet
FTA	F[ind] The Army
FTAM	File Transfer Access and Management
FTG	F[ind] The Guard
FTI	Fixed Target Indicator
FTP	File Transfer Protocol
FTS	Federal Telephone System
FU	Smoke (from French)
FUBAR	[Fouled] Up Beyond All Recognition
FVLF	Fixed, Very Low Frequency
FW	Fighter Wing (USAF)
FWA	Fixed Wireless Access
fwd	forward
FWIW	For What It's Worth
FY	Fiscal Year
FYI	For your information
FZ	freezing
FZRANO	freezing rain sensor not available
G	Conductance, reciprocal of R, in mhos, ohm backwards
G	Gust
G-SWF	Gradual Shortwave Fadeout (ionospheric disturbance)
G-TOR	Golay Transmissions Over Radio (Kantronics version of PACTOR)
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
GAFRAN	Stationary German Air Force
GAK	Government Access to Key
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
GBDL	Ground Based Data Link
GBS	Ground Based Sensor
GCA	Ground Controlled Approach
GCBS	Ground Control Bombing System
GCCS	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
GD	CW brevity: Good
GDOC	Geographical Display Operations Computer
GE	(1)General Electric
GENSER	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
GETS	Government Emergency Telecommunications Service (US NCS)
GFAE	Government-furnished aerospace equipment
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	Government-furnished part
GFP	Government-furnished property
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
GIS	Geographical Information System
GLONASS	Global Navigation Satellite System (Russian GPS)
GM	(1)CW brevity code: Good Morning
GM	(2)General Motors
GM	(3)General Manager
GMDSS	Global Maritime Distress & Safety System
GMF	Ground mobile forces
GMRS	Gneral Mobile Radio System
GMS	Geostationary Meteorological Satellite (Japanese)
GMT	Greenwich Mean Time (obsolete, kept only by BBC)
GNA	Gulf News Agency
GNC	(1)guidance and navigation computer
GNC	(2)guidance, navigation and control
gnd	ground
GNDCON	Ground Control
gnu	Gnu is Not Unix, freeware op-system
GO	General Officer
GOA	Gone on Arrival (police)
GOES	Geosynchronous Oceanic & 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)
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
GPS	Global Positioning System
GR	Hail (from French)
GRADU	Gradual weather change
GRC	General Radio Communications (AN/GRC-xxx)
grep	Global Regular Expression, Print; Unix text search
grp	Group
GRT	Gross register tonnage
GS	General support
GS	Group Separator (ASCII)
GS	small hail and/or snow pellets
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
GSMP	General Switch Management Protocol
GSTS	Ground-based surveillance and tracking system
GTC	Greek Telegraphy Club, aka SV-CW-C
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
GTS	Global Telecommunication System (WMO)
GUI	Graphical User Interface
GUID	Globally Unique Identifier
GVAR	GOES Variable
GW	(1)Gigawatt
GW	(2)Ground wire
GW	(2)CW brevity code: Good Evening
GWARC	General World Administrative Radio Conference
GWEN	Ground wave emergency network (VLF strategic net)
GWT	Gross Weight Tonnage
H	Henry (unit of inductance)
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
HAL	(1)High-order Assembly Language (space shuttle computers); named for:
HAL	(2)Heuristically programmed Algorithmic Computer (2001: A Space Odyssey)
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
HBI	Horizontal Blanking Interval (TV)
HBT	Heterojunction Bipolar Transistor
HC-ARQ	Hagelin-Cryptos simplex teleprinter system
HCP	Health and comfort package
HD	(1)Hard Disk
HD	(2)High Density
HDB	High-Density Bipolar
HDD	Hard Disk Drive
HDLC	High-level Data Link Control, old synchronous computer protocol
HDSL	High-rate Digital Subscriber Line
HDTV	High-Definition Television
HDX	Half-duplex
HE	(1)high energy
HE	(2)high explosive
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
HERE	Hazards of Electromagnetic Radiation to Equipment
HERF	High-Energy RF (weapons)
Hertz	Unit of frequency, named for Heinrich Hertz, 1Hz=1 cps
HETS	(1)heavy equipment transporter system
HETS	(2)heterodynes
Hex	Hexadecimal number notation, base 16
HF	High Frequency (3-30 MHz)
HFCC	High-Frequency Coordination Conference
HFDL	High-Frequency Data Link, sounds like ANDVT
HFDLP	HF Data Link Protocol
HFGCS	High Frequency Global Communication System (Scope Command)
HFMOD	Australian Defence Force High Frequency Modernisation Project
HFNC	HF Network Controller
HFO	High-Frequency Oscillator
HFS	Hierarchical File System
HFSWR	High-Frequency Surface-Wave Radar
HHS	(Dept. of) Health & Human Services
HI	CW brevity code: a laugh (all dits, easier to send than "HA")
Hi-fi	High Fidelity (audio)
HICOM	High Command net (US Navy)
HIPAS	High-Power Auroral Stimulation
HIPPI	High Performance Parallel Interface
HISCAT	High-latitude, High-altitude, High-power, High-frequency, High-performance, Heating and ionospheric Scatter facility (research)
HIWAS	Hazardous Inflight Weather Advisory Service
HM	Her Majesty
HMCS	Her Majesty's Canadian Ship
HMMWV	High mobility, multipurpose wheeled vehicle (hummvee)
HMS	Her Majesty's Ship
HNG-FEC	Hungarian diplo FEC teleprinting system
HNMP	HF Network Management Protocol
HNS	Host nation support
HOLF	Helicopter Outlying Landing Field
hp	Horsepower
HP	(1)High Pass (filter circuit)
HP	(2)Highway Patrol
Hpa	Hectopascal
HPE	CW brevity code: "Hope to..."
HPI	High-Priority Intercept (global HF comint system)
HPTS	High-Power Transmitting System (TACAMO)
HQ	Headquarters
HQDA	Headquarters, Department of the Army
hr	Hour
HRC	Harmonically Related Carrier (CATV channel scheme)
HRMP	HF Relay Management Protocol
HRPT	High Resolution Picture Transmissions
hrs	Hours
HRT	Hostage Rescue Team (FBI)
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)
HTML	Hypertext Markup Language (world wide web)
HTS	High Temperature Superconducting
HTTP	HyperText Transmission Protocol (WWW)
HTTP-NG	HTTP Next Generation
HTTPD	HTTP Daemon (Unix)
HTTPS	(1)HTTP Server
HTTPS	(2)HTTP with Secure Sockets Layer
HUMINT	Human Intelligence (spies!)
HVAR	High-Velocity Aerial Rocket
HW	CW brevity code: "How do you copy me?"
hx	Signal is a harmonic
HYDROLANT	Hydro-Meterological bulletins for Atlantic Ocean
HYDROMET	Hydro-Meterological bulletin or warning
HYDROPAC	Hydro-Meterological bulletins for Pacific Ocean
Hyperfix	Hyperbolic Radio Navigation System (proprietary name)
Hz	Hertz (a "cycle per second")
HZ	haze
I	(1)Current (in amperes, amps)
I	(2)Packet designator: information frame
I/O	Input/Output (computers)
i18n	Alphabet scheme for multi-lingual computer programs [~]
IA	Information Assurance
IAEM	International Association of Emergency Managers (was NCEM)
IAF	Italian or Irish air force
IAGA	International Association of Geomagnetism and Aeronomy
IANA	Internet Assigned Numbers Authority
IAPS	I Am Pretty Sure
IARN	International Amateur Radio Network
IARP	International Amateur Radio Permit (to operate overseas)
IARU	International Amateur Radio Union
IAS	Indicated Air Speed
IATA	International Air Transport Association
IAU	International Astronomical Union
IAW	In accordance with
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
IC	(4)In-cloud lightning
IC	(1)Integrated circuit (chip)
IC	(2)Incident Command
IC	(3)Ice crystals
ICAO	International Civil Aviation Organization
ICAP	Internet Calendar Access Protocol
ICBM	Intercontinental Ballistic Missile
ICMP	Internet Control Message Protocol
ICOM	(1) Intercom
ICOM	(2) Japanese radio mfr  [~]
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
ICW	interrupted continuous wave
ID	Identification
IDE	Intelligent Drive Electronics (small HD standard)
IDE	(3)Integrated Developer Environment
IDM	Improved Data Modem
IDSL	ISDN Digital Subscriber Line
IEC	International Electrotechnical Commission
IED	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"
IFL	International Frequency List, ITU doc on fiche or 2 CDs
IFOR	Implementation Force ("UN peacekeepers")
IFR	(1)Instrument Flight Rules
IFR	(2)"I Follow Roads"
IFRC	International Frequency Registration Board
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
ILS	Instrument Landing System
IM	Intermodulation, causes spurious signals or distortion
IMA	Individual Mobilization Augmentee (FEMA)
IMAP	Internet Message Access Protocol
IMC	Internet Mail Consortium
IMD	Intermodulation Distortion
IMHO	In My Humble Opinion (Internet)
IMI	CW prosign: interrogative; more often written "?"
IMO	(1)International Maritime Organization, part of UN
IMO	(2)In My Opinion (Internet)
IMS	Integrated Maritime Surveillance
IMSA	International Municipal Signal Association
IMSP	Internet Message Support Protocol
IMTS	Improved Mobile Telephone System
in	inch
INA	Iraqi News Agency
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-M	INMARSAT terminal, voice only, not GMDSS-compliant
INO	Indian Ocean (MWARA)
INS	(1)Immigration & Naturalization Service (US)
INS	(2)Inertial Navigation System
INSCOM	US Army Intelligence and Security Command
INSCOM	Intelligence and Security Command
Int	International, interrupted, interrupt
intel	intelligence
Internet	Global interconnection of regional nets using TCP/IP
InterNIC	Internet Network Information Center
INTERPOL	International Criminal Police Organization
Intl	International, internal
IOC	Index of co-operation (a fax parameter)
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
IPI	Intelligent Peripheral Interface
IPng	IP next generation
IPS	Inches per second
IPS	Ionospheric Prediction Service (Australia, original name for space weather agcy)
IPSS	International Packet SwitchStream, now GNS (UK)
IPT	Integrated Program Team
IPX	Internetwork Packet Exchange (Novell)
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)
IRE	Institute of Radio Engineers, now IEEE
IRI	Ionospheric Research Instrument, transmitter part of HAARP
IRINT	Infrared intelligence
IRIS	Improved Radio Ionospheric Sounder
IRQ	Interrupt request (computer hardware)
IRS	(1)Information Receiving Station (SITOR)
IRS	(2)Internal Revenue Service (US)
IRS	(3)Infernal Revenue Service (U$)
IRS	Information Receiving Station
IS	(1)Interval signal
IS	(2)Intermediate Standard, formerly RS
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
ISB	(1)Independent Sideband
ISB	(2)Intermediate Staging Base
ISC	Initial Scope Command (phase I)
ISD	Inverted Scanning Direction (radiofax)
ISDL	ISDN Digital Subscriber Line
ISDN	Integrated services & data network (telco)
ISF	International Science Foundation
ISMLS	Interim Standard Microwave Landing System
ISO	International Organisation for Standardisation
ISODE	ISO Development Environment
ISP	Internet service provider
ISR	In-System Reprogrammable
ISS	(1)Information Sending Station (SITOR)
ISS	(2)International Space Station
ISSO	Information Systems Security Organization (US)
ISTR	I Seem To Recall
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)
ITO	Installation transportation office
ITS	Institute for Telecommunication Sciences
ITU	International Telecommunications Union
ITU-R	ITU Sector for Radiocommunications, old CCIR
ITU-T	ITU Sector for Telecommunications, old CCITT
ITU-T	International Telecommunications Union - Telecommunication Standardization Sector
ITU-TSS	ITU Telecommunications Standards Section, old CCITT
IUGG	International Union of Geodesy and Geophysics
IUWDS	International Ursigram and World Days Service
IVAS	Inward Voice Activated Services (telco)
IVTT	Integrated VERDIN Transmit Terminal
IWTS	Integrated Terminal Weather System
J/S	Jamming to signal ratio
J2	Intelligence directorate at a joint headquarters
J3E	Single sideband, suppressed carrier AM radiotelephony (emission designator)
J4	Logistics directorate at a joint headquarters
JAA	Joint Aviation Authorities (Europe)
JAFO	Just Another F[ine] Observer
JAN	Joint Army/Navy (spec)
JANA	Jamahiriyah News Agency
JANET	Joint Academic NETwork (UK)
JAR	Joint Aviation Requirements (Europe)
JASORS	Joint Advanced Special Ops Radio System
JASORS	Joint Advanced Special Operations Radio System
JATACS	Joint Advanced Tactical Command and Control System
JATCC	Joint Air Traffic Control Center
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
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)
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	Transmission is in Japanese
JJ	Joprep Jiffy (obsolete SAC weather report form)
JJY	Japanese standard frequency & time station [~]
JMC	Joint movement center
JMPA	Joint Military Postal Agency
JMRO	Joint medical regulating office
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," aircraft heard on HF during Haitian operation
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
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	(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 Index	Logarithmic, 3-hourly geomagnetic activity reading
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
kc	Kilocycles per second, now kHertz
KCNA	Korean Central News Agency
kcs	Kilocycles per second, now kHertz
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
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.)
Kp	Planetary K index
kph	kilometer per hour
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
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)
LA	Low altitude
Ladar	Laser Radar
LAN	Local Area Network
LANL	Los Alamos (NM) National Laboratory
LAPD	(1)Link Access Procedure D-Channel
LAPD	(2)Los Angeles Police Department, famous organized crime family
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
LBA	Logical Block Addressing (Disk access)
LC	Limited Coastal (service)
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
LHCP	Left-hand circular polarization
Lidar	Light Detection & Ranging (light "radar")
LIM	(1)Lotus/Intel/Microsoft, original spec for PC extended memory
LIM	(2)Line interface module
LINCOMPREX	Link Compression and Expansion, an ACSB system
LIRL	Low Intensity Runway Lights
LL	Landline, "Lima Lima"
LLC	(1)Logical Link Control
LLC	(2)Limited Liability Corporation (US)
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
LO	Local oscillator (of a receiver)
LOC	(1)lines of communication
LOC	(2)location
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
Long Range Accuracy (NASA booster recovery)
LORAN	Long Range Navigation
LOS	(1)Loss Of Signal
LOS	(2)Line of sight
LOTS	logistics-over-the-shore
LP	(1)Long Playing (old records)
LP	(2)Low pass (filter circuit)
LP	(3)Linking Protection (US mil ALE security)
LPB	Logistics preparation of the battlefield
LPD	Line Printer Daemon
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)
LQA	Link Quality Analysis (databursts heard from ALE radios)
LRA	Landing Rights Airport
LRC	Longitudinal Redundancy Check (computing)
LRCOC	Long Range Company Operational Control
LSB	Lower Sideband
LSDIS	Light and Special Division Interim Sensor (US Army)
LSE	Logistics support element
LSI	Large scale integration (of chips)
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
LWR	lower
LZW	Lempel-Ziv-Welch, lossless compression algorithm for data
M	Mega, meg, a million of anything, or 1,048,576 bytes (hex)
m	Meter (39.37 inches)
M	minus, less than
M	Minus (Below zero C)
M-JPEG	JPEG used for moving pictures (cf JPEG, MPEG)
M/S	Motor Ship (also MS, M.S.)
m/v	Motor Vessel (also MV)
M/V	Motor Vessel (also m/v)
mA	milliamperes
Mac	Macintosh (computer)
MAC	(1)Military Airlift Command, now AMC
MAC	(2)Media Access Control (computer networks)
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
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)
MARC	MAchine Readable Catalog
MARO	Maritime Air Radio Organization
MARS	Military Affiliate Radio System (US)
MARSA	Military Assumes Responsibility for Separation of Aircraft
MASER	Microwave Amplification by Stimulated Emission of Radiation
MASH	mobile army surgical hospital, may be obsolete
MASM	Macro-Assembler (computer code)
MATS	Military Air Transportation Service, became MAC, now AMC
MAU	Media Attachment Unit, a network transceiver
MAYDAY	Prosign: Distress traffic follows; repeated 3 times [~]
mb	millibar
MB	Megabyte
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	Multimode Communications Processor (packet)
MCS	Mission Communications System
MCS/P	Maneuver Control System/Phoenix (US Army)
MCVFT	Multichannel Voice Frequency Telegraph (multiplex RTTY)
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
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
MERS	Mobile Emergency Response Support (FEMA)
MET	Meterological
Met Office	Weather office at a base
METAR	Meteorological observation code for routine aviation
METAREA	Meteorological Area, same as a NAVAREA (see WMO)
Meteo	Meteorological
METOC	Meteorological and Oceanographic
Metro	Meteorological office
METSAT	Meterological Satellite
MF	(1)Medium Frequency (300-3000 kHz)
MF	(2)Multifrequency
MFA	Ministry of Foreign Affairs
MFD	Modulated Fractional Division
MFM	Modified Frequency Modulation (Miller Coding)
MFSK	Multiple Frequency Shift Keying
mgt	management
MHD	Magnetohydrodynamics; behavior of plasmas in magnetic fields, such as the ionosphere and sunspots
MHE	materials-handling equipment
MHS	Message Handling System
MHz	MegaHertz
mi	mile (1.6 km)
MI	Military intelligence, especially in UK
MI	shallow
MI5	Directorate of Military Intelligence, group 5 (domestic)
MI6	Directorate of Military Intelligence, group 6 (foreign, aka SIS)
MIB	Management Information Base
MID	(1)Middle East (MWARA)
MID	(2)Maritime Identification Digits, country code prepended to MMSI
MID	Maritime Identification Digit
MIDS	Multifunctional Information Distribution System
MIFG	Shallow Fog
MIJI	Meaconing, Intrusion, Jamming & Interference ("Jammer writeup")
Mil	(1) Military
Mil	(2) Milliampere
MIME	Multipurpose Internet Mail Extensions, allows attachment of binaries to letters
MIMS	Medical Information Management System
min	Minute
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
MIT	Massachussetts Institute of Technology
mkr	Marker
ML	Machine language, how computers store instructions
MLB	Motor Lifeboat
MLS	Microwave Landing System
MLSO	Mauna Loa Solar Observatory
MLT	Magnetic Local Time
MM	Maritime mobile
mm	Millimeter
MMC	materiel management center
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
Mob	Mobile
MOC	(2)Ministry Of Commerce (Canada)
MOC	(1)Mission Operation Center
MOCA	Minimum Obstruction Clearance Altitude
Mod	Modification (to radio)
MoD	Ministry of Defence (UK)
Modem	Modulator/Demodulator
MOOTW	Military operations other than war
MOP	Measure Of Performance
MOPP	mission-oriented protection posture (0-4, 4 being full suit)
MOS	Metallic Oxide Silicon
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
MP	(1)Military Police (US)
MP	(2)Member of Parliament (UK)
MP	(3)Multiprocessor (computer h/w)
MP	Magnetopause
MP3	MPEG Level 3, CD-quality compression scheme
MPEG	Motion Picture Expert Group, lossy compression for video
mph	mile per hour
MPSA	Military Postal Service Agency
MPSAP	Mobile Public Safery Answering Point
MPX	Multiplex
MR	Magnetoresistive
MRB	Marine Radio Beacon
MRC	Mobile Radio Communications
MRCC	Maritime Rescue Coordination Center
MRE	meal, ready-to-eat
MRO	medical regulating office
MRS	Mountain Radio Service
MRT	Mountain Rescue Team
ms	millisecond
MS	Motor Ship
MS	Master Station
MSB	main support battalion
MSC	Military Sealift Command
MSC	Military Seaflift Command (US)
MSE	mobile subscriber equipment
MSF	English standard frequency & time station
MSFC	NASA Marshall Space Flight Center
msg	Message
MSI	Maritime Safety Information
MSI	Marine Safety Information
MSI	Maritime Safety Information
MSIS	Mass Spectrometer Incoherent Scatter (research)
MSR	main supply route
MSS	Mobile Satellite Service
MST	(1)Mountain (US) Standard Time, zone includes Rockies
MST	(2)Maintenance support team
MT	Monitoring Times (**the bible**)
MT	mountains
MTA	Message Transfer Agent
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
MTU	Maximum Transmit Unit (TCP/IP packet length)
MUF	Maximum Usable Frequency (varies with path)
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	Music
MX	Mail Exchange Record
MYM	My Mailbox (packet)
MYP	Personal Mailbox (packet)
N	north
N	No Change
N-ISDN	Narrowband ISDN
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)
NABER	National Association of Business/Emergency Radio
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)
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
NATO	North Atlantic Treaty Organization
NAV	Navigation
NAV/COMM	Airplane Navigation/Communication radio
NAVAID	Navigational aid
NAVAREA	Navigational Area (IMO/IHO)
NAVCEN	USCG Navigation Center, VA
NAVMARCORMARS	Navy/Marine Corps Military Affiliate Radio Service (US)
NAVMTO	Navy Material Transportation Office
NAVSAT	NAVigation SATellite
NAVTEX	Navigational Telex, Navigational Text (518 kHz SITOR-B)
NAWC	Naval Air Warfare Center
NAWC-WPN	Naval Air Warfare Center
NAWCAD	Naval Air Warfare Center Aircraft Division
NAWS	(1)Naval Air Weapons Station
NAWS	(2)Old group call: Notice to Allied Warships
NB	Narrowband
NB	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
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
NCDC	National Climatic Data Center
NCEM	National Coordinating Council for Emergency Management, now IAEM
NCFSK	Non-Coherent Frequency Shift Keying
NCIC	National Crime Information Center, US database of police records
NCO	Non-Commissioned Officer
NCPi	Netware Core Protocol
NCR	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)
NCTSI	Navy Center for Tactical Systems Interoperability (US)
ND	Nondirectional
NDB	Nondirectional beacon
NDIS	Network Driver Interface Specification
NDS	NUDET Detection System, see NUDET
NE	Northeast
NEACP	National Emergency Airborne Command Post, "kneecap," now NAOC
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
NEST	Nuclear Emergency Search Team ("Flynest")
NET/ROM	Network packet radio protocol
NetBEUI	NetBIOS Extended User Interface
NetBIOS	Network Basic Input/Output System
NFCC	National Frequency Coordinators' Council
NFR	Navy Fleet Relay (USN secure satcom)
NFS	Network File System
NGO	Nongovernmental organization
NHC	National Hurricane Center
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"
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 (sensitive military net)
NIS	Network Information System
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	Nautical Mile; about 1.24 statute miles
Nm	Nautical Mile (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
NMEA	National Marine Electronics Assn
NMF	US Coast Guard COMMSTA, Boston, will be ctld from CAMSLANT
NMG	US Coast Guard COMMSTA, New Orleans, will be ctrld 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
NNTP	Network News Transfer Protocol (USENET)
NNW	North-northwest
NOAA	National Oceanic & Atmospheric Administration
NOC	Network Operation Center
NOE	Nap-Of-the- Earth (low altitude attack)
NOI	Notice Of Inquiry (FCC rulemaking)
NOJ	US Coast Guard COMMSTA, Kodiak
NORAD	North American Aerospace Defense Command
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	New, Old-Stock (wine or vacuum tubes)
NOS	(2)National Ocean Service
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)
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
NRL	Naval Research Laboratory (US)
NRO	National Reconnaissance Office (operates US spy satellites)
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")
NSE	National Support Element
NSF	National Science Foundation (US)
NSFNET	National Science Foundation Network, old Internet backbone
NSK	Narrowband shift keying
NSTAC	National Security Telecommunications Advisory Committee (US)
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)
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
NVRAM	Nonvolatile Random Access Memory
NW	(1)CW brevity code: "Now," or "New"
NW	(2)Northwest
NWR	NOAA Weather Radio
NWS	(1)National Weather Service (US)
NWS	(2)Naval Weapons Station
NWSFO	National Weather Service Forecst Office
nx	News
NYSEMO	New York State Emergency Management Office
O&O	Owned & Operated (by broadcast network)
o/l	Online
O/R	On request
O/R Address	Originator/Recipient Address
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
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
OD	(1)Officer of the Day
OD	(2)Overdose
ODBC	Open DataBase Connectivity (Microsoft)
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
OFP	Operational Flight Program
OG	Operations Group
OHD	overhead
OIC	Officer In Charge
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	Global LF navigation system, replaced by GPS
OMS	("ohms") Orbital Maneuvering System (NASA)
OOB	(1)Out of band
OOB	(2)Out Of Bounds (classic Internet hack)
OOK	On-off keying
OOOI	Out, Off, On, In (ACARS time reporting)
op	Operation
OP	Observation Post
OPAL	Orbiting Picosat Automatic Launcher
OPC	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
OR	Offroute (unscheduled flights, usually military)
ORBS	Open Relay Behaviour-modification System (anti-email-spam)
ORFM	Office of Radio Frequency Management
org	organization (Internet)
OS	Operating system (code that runs a computer)
OS/2	Operating System II (IBM)
OS/2	Operating System 2, proprietary IBM op-system for PS/2
OSC	Operations Systems Center, USCG, VA
OSCAR	Orbiting Satellite Carrying Amateur Radio
OSCE	Organization for Security and Cooperation in Europe
OSCR	Ocean Surface Current Radar
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
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
P	Power (in watts)
P	greater than
P	Plus
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
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
PADIL	PATRIOT Digital Information Link (US missile batteries)
PAL	Phase Alternate Line (W. Europe TV standard)
PAM	Phase-Amplitude Modulation, modems
PAM	Pluggable Authentication Modules (Linux)
PAN	Prosign: priority safety traffic follows (also "PAN PAN") [~]
PANA	Pan-African News Agency
PanAmSat	Pan American Satellite Co., operates 17 COMSATs
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
PAVE	Precision Acquisition Vehicle Entry
PAVE PAWS	Phased array SLBM warning system, 4 US Coastal sites
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	Personal Computer
PCI	Peripheral Component Interconnect (Intel)
PCM	Pulse code modulation
PCMCIA	Personal Computer Memory Card International Association
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)
PDF	Portable Document Format (Adobe)
PDM	Pulse Duration Modulation
PDT	Pacific Daylight Time, US
PDU	Protocol Data Unit
PE	ice pellets
PEM	Privacy Enhanced Mail
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	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.)
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
PL	(1)"Private Line," Motorola tradename for CTCSS
PL	(2)Pilot light
PL/1	Programming Language 1 (computer code)
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
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
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
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)
POSIX	OSI standard, like Unix
POSIX	Portable Operating System Interface
POST	Power-On Self Test
POTS	(1)Plain Old Telephone System
POTS	(2)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
PPM	(1)portable pixmap
PPM	(2)Page per minute
PPM	(3)Parts per million
PPM	(4)Pulse Position Modulation
PPP	Point-to-Point Protocol
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)
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
Prosign	Procedural Signal ("over," etc.)
PRZ	Polar Return to Zero
PS/2	Personal System 2, IBM's less-than-sensational replacement for the PC
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
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
PTD	Pilot-to-dispatcher
PTO	Permeability tuned oscillator
PTT	(1)Push to talk
PTT	(2)Post, Telegraph and Telephone administration (UK)
PU	("Papa Uniform") participating unit
pub	publication
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	Quality (measure of selectivity in inductive circuits)
Q	HectoPascals (U.S. METAR variant)
QCWA	Quarter Century Wireless Association (amateur)
QLF	Facetious prosign: Now send with your LEFT foot
QNH	Set your altimeter to -- barometric pressure
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
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
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	(1) CW prosign: "Message received"
R	(2) DC resistance (in ohms)
R	right (with reference to runway designation)
R	Runway
R	Right
R chks	Radio checks
R&D	Research & Development
R/T	Receiver/Transmitter
R/W	Rotary wing (helicopter)
R3E	Single sideband, reduced carrier (usually 6 dB) radiotelephony; CHU and CIA counter are R3E
RA	Rain
RAAF	Royal Australian Air Force
RACES	Radio Amateur Civil Emergency Service, FEMA affiliates
Racon	Radar Beacon
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 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	Italian national broadcaster
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)
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
RASC	Radio Atmospheric Science Center (Japan)
RASP	Radio Science And Propagation
RATCF	Radar Air Traffic Control Facility (USN)
RATT	Radioteletype
RAV	Restricted Availability
RB	Radar Beacon
RBL	Realtime Blackhole List (spam filtering)
RBL	Realtime Blackhole List (Internet)
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
RCMA	Dead scanner radio club, which included HF utility
RCNC	Range communications network controller
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
RDARA	Regional and Domestic Air Route Area
RDF	Radio direction finding
RDM	Radio Data Modem
RDNS	Reverse Domain Name System (Internet)
RDRAM	Ram bus (interface scheme) Dynamic Random Access Memory
RDS	Remote Data Service
RDT	Remote digital terminal
RE	Reverse engineering
REACT	Radio emergency team, like ARES, only uses CB and GMRS
rec	receive
REC	Radio-electronic combat
recon	reconnaissance
REDHORSE	Rapid Engineer Deployable Heavy Operational Repair Squadron, Engineer
REE	Radio Espana Exterior (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-equivalent, man (nuclear safety)
REP	Radiological Emergency Preparedness (program)
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	Request For Comment
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
RFPI	Radio For Peace International, Costa Rica
RFR	RF radiation
RG#	Radio Guide, coax cable designator
RGB	Red, Green, Blue; additive color mixing like TV
RGS	Remote ground station
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)
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"
Rlogin	Remote Login, networking program like telnet
RM	("Romeo Mike") Radioman, radio operator
RMA	Revolution in Military Affairs (US tax subsidized paper crunching)
RMC	Regional Meteorological Center
RMI	Radio Magnetic Indicator
RMI	Republic of the Marshall Islands
RMK	Remarks
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	Read News, usually the default Unix Usenet reader
RN	(1)Radio Netherlands
RN	(2)Royal Navy
RN	(3)Registered Nurse
RNR	Packet control frame: Receive Not Ready
RNZAF	Royal New Zealand Air Force
RNZN	Royal New Zealand Navy
RO	Radio Officer (traditionally trained in Morse code)
RO	Receive Only
ROA	Remotely Operated Aircraft
ROC	(1)Regional Operating Center (FEMA/NCS)
ROC	(2)Rear operations center
ROCC	Regional Operations Control Center
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)
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	Remote Passphrase Authentication
RPG	Report Program Generator (strange IBM computer language)
RPI	Runway Point of Intercept
rpm	Rotations per minute
RPM	Red (Hat) Package Manager (Linux)
RPN	Reverse Polish Notation (computing)
rpt	(1) Reception report
rpt	(2) CW prosign: repeat
Rptr	Repeater
RQ	Repeat Request
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
RRC	Regional Radio Conference (ITU)
RRP	Runway Reference Point
RRSS	Radparker Relay Spam Stopper
RRx	Routine Report, where x is a sequential letter, used for delayed METAR
RS	(1)radiated susceptibility
RS	(2)range squadron
RS	(3)reentry system
RS	(4)requirements submission
RS	(5)resource scheduling
RS	(6)Radio Satellite (Russian amateur)
RS	(7)EIA Recommended Standard, RS-232 was one
RS	Record Separator (ASCII)
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
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	Radio Subsystem
RST	(1)Signal report: Readability, Strength, [Tone] (if CW)
RST	(2)Reset
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	routing table
RTB	Return to base
RTCA	Radio Technical Commission for Aeronautics
RTCA	Radio Technical Commission for Aeronautics
RTCE	Reat-Time Channel Evaluation
RTCM	Radio Technical Commission for Maritime (service)
RTCP	Real Time Control Protocol
RTD	Return to duty
RTDC	Real time data controller
RTF	(1)Radiodiffusion Television Francais
RTF	(2)Runtime file
RTFM	Read the [fine] manual
RTFMS	Real-Time (HF) Frequency Management Software
RTLS	(1)Return to launch site
RTLS	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	Radioteletype
RTTY	Radioteletype
RTZ	Return To Zero
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)
RY	RYRYRY teleprinter test call
RZ	Return to Zero
S	south
S-band	1.55-5.2 Ghz microwave band
s/n	Serial number
S/N	Signal/Noise ratio
s/off	Sign off
s/on	Sign on
s/w	software (computer programs and instructions)
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	Situational Awareness
SA	(2)Sand
SAA	South Atlantic Anomaly, a large magnetic deviation
SAAF	Small Austere Air Field
SAAFR	Standard use Army Aircraft Flight Route
SABM	Packet control frame: Set Async Balanced Mode (connect)
SAC	Strategic Air Command, now part of US Stratcom
SACCS	Strategic Automated Command & Control System
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")
SANA	Syrian Arab News Agency
SAO	South Atlantic Ocean
SAO	Surface Aviation Observation (weather)
SAP	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
SARSAT	Search And Rescue Satellite
SART	(1) Survival Craft Radar Transponder
SART	(2) Search And Rescue Transponder
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
SB	(1)Standby (EIA-449)
SB	(2)Sierra Bravo, son of a [female dog]
SBA	Small Business Administration
SBE	Society of Broadcast Engineers
SC	Sudden commencement (of a magnetic storm; causes fadeouts)
SCA	(1)Subsidiary Communications Authorization (US commercial FM)
SCA	(2)Shuttle Carrier Aircraft (NASA's modified 747 for transporting orbiter)
SCAT	Strategic Communications (Continuing) Assessment Program
SCCS	satellite communications control system
SCDCC	Southern California Digital Communications Council (Amateur)
SCI	San Clemente Island (USN, CA)
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
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
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
SDRAM	Synchronous Dynamic Random Access Memory
SDSL	Symmetric Digital Subscriber Line
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
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
SEE	Stimulated Electromagnetic Emissions
SELCAL	Selective Calling (tones or numbers)
SELFEC	Selective FEC
SELSCAN	Proprietary name for Collins scanning ALE HF radio system
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	Bourne Shell, originally the Unix default command interpreter
SH	(Rain) Showers
SHAEF	Supreme Headquarters, Allied Expeditionary Forces
SHAPE	Supreme Headquarters, Allied Powers, Europe
SHARES	SHAred RESources, part of US Federal NCS
SHF	super high frequency
SHTTP	Secure Hypertext Transfer Protocol (web)
SI	(1)Systeme Internationale d'Unites; a standard unit system
SI	(2)Shift In (ASCII)
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
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
SIPRNET	Secret IP Router Network
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
SJA	Staff judge advocate
SK	CW prosign: "End of transmission," usually written VA
SKC	Sky clear
SKYWARN	NWS/ARRL amateur severe weather spotting network
SLB	Single Letter Beacon (Russian Navy marker xmsn)
SLBM	Sea-Launched Ballistic Missile
SLEP	Service Life Extension Program
SLIP	Serial-Line Internet Protocol, older than PPP
SLOC	Sea lines of communication
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	Segmented Method for Analytical Ray-Tracing
SMB	Server Message Block (Windows)
SMF	Special Message Field
SMMW	Sub-millimeter wave
SMRS	Specialized Mobile Radio System
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
SO	(1)Sheriff's Office
SO	(2)Shift Out (ASCII)
SO DIMM	Small Outline Dual Inline Memory Module
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)
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
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
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
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	Service Provider Interface
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	Spectrum Planning Subcommittee (of IRAC)
SPSS	Space Surveillance Squadron
Spt	Support
SPX	Sequenced Packet Exchange
SQ	squalls
sqdn	Squadron
SQL	Structured Query Language (computer databases)
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
SSA	Supply support activity
SSB	Single Sideband
SSC	Sudden Storm Commencement (geophysics)
SSE	South-southeast
SSF	Southern Straits of Florida
SSG	The Space Systems Group
SSI	Server Side Includes (web)
SSI	Space Science Institute
SSID	Secondary Station Identifier (packet)
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	Secure Tactical Army Radio 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
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)
SUB	Substitute (ASCII)
SUNA	Sudan News Agency
SuperDARN	Super Dual Auroral Radar Network
suppl	supplement
SURFnet	Dutch academic network
SUV	Sport-Utility Vehicle
SV-CW-C	Greek Telegraphy Club, aka GTC
svcs	services
SVP	(1)Single Line Variety Package (telco)
SVP	(2)Si Vous Plait ("If you please" in French)
SW	(1)Shortwave (high frequency - HF)
SW	(2)Southwest
SWBC	Short Wave Broadcasting
SWED-ARQ	Swedish ARQ teleprinter system, used by that country
SWG	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
SYN	Synchronous Idle
SYNOP	Synoptic weather reports (from surface observations)
Sysop	System Operator, the king on a BBS
t	Time (in seconds)
T	(1)US Coast Guard C3 office, DC; aka G-T
T	(2)Boston transit system
T-Plex	8-frequency duplex ARQ teleprinter system
T/R	Transmit/Receive switching
T1	Relatively high speed data connection over phone line
tac	tactical
TAC	Tactical Air Command, now ACC
TAC	Technical Advisory Committee
TACACS	Terminal Access Controller Access Control System
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
TADIL	Tactical Digital Information Link (US)
TAF	Terminal Area Forecast, weather at airports, like on VOLMET
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
TAS	True Air Speed
TASMA	Two-meter Area Spectrum Management Assn. (Amateur)
TAW	Tactical airlift wing
TAWC	Tactical Air Warfare Center
TBD	To Be Determined
TCAS	Traffic (Alert) & Collision Avoidance System
TCC	Telecommunications center
TCF	Tactical combat force
TCH	Threshold Crossing Height
TCP	Transmission Control Protocol
TCP/IP	Transmission Control Protocol/Internet Protocol
TCPOD	Tropical Cyclone Plan Of the Day
TCS	Tactical Control System
TCU	Towering Cumulus
TD	(1)Transmitted Data, short for TXD
TD	(2)Transmitter/Distributor (old RTTY)
TDA	Table of distribution and allowances
TDD	Time Delay Distortion
TDM	Time-Division Multiplex
TDMA	Time Division Multiple Access
TDP	Takeoff Decision Point
TDY	Temporary duty ("to go TDY")
TEC	Total electron content (of ionosphere)
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
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
TEXN	Traffic Exchange Network (MARS)
Tfc	Traffic
tfc	Traffic
TFE	Tactical field exchange
TFEO	Tactical field exchange officer
TFW	Tactical Fighter Wing
THAAD	Theater High Altitude Area Defense
THD	Total Harmonic Distortion (audio, in %)
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	Tactical Information Broadcast System
TIFF	Tagged Image File Format, versatile computer graphic standard
TIN	Taxpayer Identification Number (same as SSN - FCC forms)
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)
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	Terminal Node Controller (packet)
TOA	Time Of Arrival
TOC	Tactical Operations Center
TOD	time of day
TOE	(1)Table(s) of organization and equipment
TOE	(2)Theory of everything (physics)
TOR	Teleprinting (or Telex) over Radio
TOW	Wire-guided missile
TPFDD	Time-phased force and deployment data
TPO	Transmitter power output
TPR	Third-Party Relay
TPRAM	Triple Port RAM
TRACAB	Terminal RAdar control in the tower CAB
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
TRUEX	Training in Urban Environment Exercise (USMC)
TS	thunderstorm
TSC	Technical Subcommittee (of IRAC)
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)
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)
TU	Terminal Unit (RTTY)
TUBA	TCP and UDP with Bigger Addresses (possible Internet extension)
TV	Television
TVA	Tennessee Valley Authority (big dam operator)
TVI	Television interference
TWA	(1)Trailing-wire antenna (USN ELF/Tacamo)
TWA	(2)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	tower
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-ATA	Ultra-AT Attachment
U/L	(1) Uplink
U/L	(2) Upload
uA	Microamp
UA	(1)Packet control frame: Unnumbered Acknowledgement
UA	(2)User Agent (Internet)
UART	Universal Asynchronous Receiver/Transmitter (computer)
UAV	Unmanned Aerial Vehicle (USAF)
UDP	User Datagram Protocol, type of Internet packet good for streaming
UDT	(1)Universal Dataflow and Telecommunications
UDT	(2)Underwater Demolition Team, crack USN WWII unit
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	Packet designator: Unnumbered Information
UID	User Identification
UIDL	User Initiated Download
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
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
UN	United Nations
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
UPS	(1)Uninterruptible Power Supply
UPS	(2)United Parcel Service
UR	CW brevity code: "Your"
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
USAF	US Air Force
USAFA	US Air Force Academy
USAFAWC	US Air Force Air Warfare Center
USAFE	US Air Forces, Europe
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	US Coast & Geodetic Survey
USIA	US Information Agency
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
USNA	US Naval Academy
USNG	US National Guard
USNO	US Naval Observatory
USNR	(1) US Naval Reserve
USNR	(2) US Navy, Retired
USO	United Service Organizations
USOS	Unshift On Space
USP	University of the South Pacific (Fiji, classes by radio)
USPACOM	United States Pacific Command
USPS	(1)United States Postal Service
USPS	(2)US Power Squadrons
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
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
UXB	Unexploded Bomb
UXO	Unexploded Ordnance
v	Velocity
V	(1)Voltage (electromotive force)
V	(2)Variable
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)
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
VDSL	Very-high-bit-rate Digital Subscriber Line
VDSL	Very high-data-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
VF	(1)Voice frequency
VF	(2)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; "do not exceed"
VOA	Voice Of America
Vocoder	Voice coder
VOLMET	Flight weather transmission, for planes in route
Volt	Unit of electrical potential, named for Alessandro Volta
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
VR	(1)Voltage regulator
VR	(2)Visual Route (air training route)
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
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	Vertical Tab (ASCII)
VTnnn	Series of old DEC terminals, still a popular emulation code
VTP	Virtual Terminal Protocol
VTVM	Vacuum-tube voltmeter
VV	Vertical Visibility (of obscured sky)
VVV	CW test group
VxD	Virtual Device Driver (MS-Windows)
VXO	Variable Crystal Oscillator
VY	CW brevity code: "Very"
W	Power, in watts
W	west
W3C	World Wide Web Consortium
WA	CW prosign: word after
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
WAGB	Icebreaker (USCG)
WAIS	Wide-Area Information Server
WAN	Wide-Area Network
WAN	Wide-Area Network Station
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)CW prosign: word before
WB	(2)Wideband
WB	(1)Welcome Back (Internet)
WB	(2)Warner Bros (Good movie studio, lousy TV network)
WBFM	Wideband frequency modulation
WCRP	(1)World Climate Research Program
WDC	World Data Center, any of several for solar-terrestrial obs
WE	Western Electric
WEFAX	Weather Facsimile
WFN	War Fighter Net
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)
whoami	Returns name you are logged in under (Unix) [~]
whois	Internet lookup program for finding people by querying servers [~]
WIFCOM	Wirefree communications (US Navy)
Wilco	Voice prosign: Will comply
WIMP	(1) Window, Icon, Mouse, Pointer (graphical interface)
WIMP	(2) Weakly Interacting Massive Particle
WINSOCK	Windows Sockets API, used for networking from Microsoft s/w
WISE	Web-Integrated Software metrics Environment
WIX	USCG designation for training barque Eagle
Wkg	Working
WL	Wordlength, size of basic data group (computing)
WLB	Seagoing Buoy Tender (USCG)
WLI	Inland Buoy Tender (USCG)
WLIC	Inland Construction Tender (USCG)
WLL	wireless local loop
WLM	Coastal Buoy Tender (Medium Endurance USCG vessel)
WLR	River Buoy Tender (USCG)
WMEC	Medium-Endurance Cutter (USCG)
WMO	World Meteorological Organization
WMSCR	Weather Message Switching Center Replacement
WND	wind
WNW	West-northwest
WORM	Write-Once Read-Many (CD-R, allows making own CD-ROMs)
WPB	Patrol Boat (USCG)
WPM	Words per minute
WRC	World Radio (Communications) Conference
WRTH	World Radio TV Handbook
WRU	Who Are You? (RTTY)
WSHFT	wind shift
WSM	Weapon system manager
WSMR	White Sands Missile Range (NM)
WSO	Weapon Systems Officer ("Whizzo")
WSRO	Weapon system replacement operations
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)
WTGB	140' Icebreaking Tug (USCG)
WU	Western Union
WUN	World Utility News, Internet group, maintains large e-mail list, rhymes with "one"
WW	Weather Warning
WWABNCPP	Worldwide Airborne National Command Post Program
WWMCCS	Worldwide Military Command and Control System, obsolescent
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
WYSIWYG	What You See Is What You Get (computers)
X	(1) Reactance, in ohms
X	(2)(Also "Xray") prosign for end of sentence
X-band	(1)8-12 GHz microwave band
X-band	(2)Expanded AM band, 1610-1720 kHz
X-windows	Standard windowing system for networks (usually Unix) [~]
XCHS	Extended Cylinder, Head, Sector (addressing)
xcvr	Transceiver
xfmr	Transformer
xistor	Transistor
xmit	Transmit mode
XML	Extensible Markup Language
XMODEM	Async file transfer protocol, uses 128-byte or 1K packets, over direct links, not Internet
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
XSL	Extensible Style Language
XT	Extra Value (PC-XT was first IBM PC with a hard disk; obsolete)
xtal	Crystal
XTP	eXpress Transfer Protocol (computers)
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! style themselves as just yahoos
YF	CW brevity code: "Wife," more typically "XYL"
YL	Female voice ("Young Lady")
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	8-bit processor chip, still made
ZCPR3	Small Z-80 operating system, improved on CP/M, obsolete

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
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; equivalent 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:

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 recommendation for wireless ethernet
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 - equiv 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

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