U.S. Army & Navy Equipment - Designations: 'AN' - System

The earlier designation systems for Army (SCR-xxx) and Navy have been replaced with the "Joint Army- / Navy Nomenclature System: after first designation assignments in December 1942, the so called "AN" designation system has been introduced in 1943.
After the U.S. Air Force separated from the Army it was the code also used by the Air Force, by the Coast Guard after Aug. 1951 und by the Army to replace older systems after June 8th 1953.

In 1957, the systems was formalized in MIL-STD-196 as "Joint Electronics Type Designation System" (JETDS), since then, the system has seen several revisions.

Similar to the older designation systems, JETDS makes a difference between "System" or "Set" and "Component" or "Part".

Sets and Systems

All designations carry the prefix "AN/" which originally stood for "Army - Navy". Even today, as JETDS is used for all electronic (communications) equipment, this prefix is still used.
Usually, on the typeplates of the sets, the "AN/" prefix is omitted.

The first letter indicates the location of the equipment:

• A - Piloted Aircraft
• B - Underwater, Mobile (submarine)
• C - Cryptographic Equipment (see note 1, 2)
• (C - Air Transportable; this installation indicator has been removed from the system)
• D - Pilotless Carrier (missile, drone, UAV)
• F - Ground, Fixed
• G - Ground, General (multiple types of ground installation; see note 3)
• K - Amphibious
• M - Ground, Mobile (see >note 4)
• P - Portable (by man)
• S - Surface Ship
• T - Ground, Transportable (see note 5)
• U - General Utility or Combination (see note 6)
• V - Ground, Vehicle (see note 4)
• W - Water Surface/Underwater Combination
• Z - Piloted/Pilotless Airborne Combination

Letter 2 stands for the type of equipment

• A - Invisible Light, Heat Radiation (i.e. infrared)
• B - Comsec (secure communications; see note 1)
• (B - Pigeon (see note 7); this type indicator has been removed from the system)
• C - Carrier (electronic wave or signal)
• D - Radiac (Radioactivity Detection, Identification, and Computation)
• E - Laser (see note 8)
• (E - NUPAC (Nuclear Protection & Control); this type indicator has been removed from the system)
• F - Fiber Optics
• (F - Photographic; this type indicator has been removed from the system)
• G - Telegraph or Teletype
• I - Interphone and Public Address
• J - Electromechanical
• K - Telemetering
• L - Countermeasures
• M - Meteorological
• N - Sound in Air
• P - Radar
• Q - Sonar and Underwater Sound
• R - Radio
• S - Special or Combination
• T - Telephone (Wire)
• V - Visual, Visible Light
• W - Armament (only used, if no other letter applies)
• X - Fax or Television
• Y - Data Processing
• Z - Communications (see note 1)

Letter 3 defines the purpose of the equipment

• A - Auxiliary Assembly
• B - Bombing
• C - Communications
• D - Direction Finding, Reconnaissance and Surveillance
• E - Ejection and/or Release
• G - Fire Control or Searchlight Directing
• H - Recording and/or Reproducing
• K - Computing
• (L - Searchlight Control; this purpose indicator has been removed from the system; purpose now covered by "G")
• M - Maintenance or Test
• N - Navigation Aid
• (P - Reproducing; this purpose indicator has been removed from the system; purpose now covered by "H")
• Q - Special or Combination
• R - Receiving or Passive Detecting
• S - Detecting, Range and Bearing, Search
• T - Transmitting
• W - Automatic Flight or Remote Control
• X - Identification or Recognition
• Y - Surveillance (target detecting and tracking) and Control (fire control and/or air control)
• Z - Secure (see note 1)

After the three letter follows the model number

Each Installation-Type-Purpose letter combination uses its own model number sequence, starting at 1.
Blocks of high model numbers are reserved for use by Canada (500-599, 2500-2599), Australia (2000-2099), New Zealand (2100-2199) and the UK (2200-2299). It seems that the first number of the Canadian block (500) is never used, i.e. Canadian designations always start with 501.

An optional suffix letter denotes a specific version of the equipment
The first version uses no suffix, the first modifcation uses "A", etc. The letters "I", "O", "Q", "S", "T", "X", "Y", "Z" are not used as version suffix. "I", "O", "Q" and "S" could be confused with numerals 1, 0 and 5 respectively, for "T", "X", "Y" and "Z".

The "(V)" symbol indicates an equipment with variable components (sets, groups or units).

Notes:
note 1: Installation letter "C", type letters "B" and "Z", and purpose letter "Z" are reserved for use by the NSA (National Security Agency) only.

note 2: "Cryptographic" is not an "installation" letter in the proper sense. It should have been a new "type" or "purpose" letter.

note 3: Installation letter "G" is used, when two or more of "F", "M", "P", "T" or "V" apply.

note 4: Installation letter "M" is only used if the vehicle housing the equipment is solely designed for this purpose, i.e. the vehicle is a part of the equipment. For equipment installed in other vehicles, like tanks, etc., installation letter "V" is used.

note 5: Installation letter "T" is only used, if none of "G", "M", "P", "U" or "V" can be applied. It is intended for equipment, which can be moved, but can't be operated while in motion.

note 6: Installation letter "U" is used in following two principally different cases:
- Equipment items (e.g. a radio AN/URC-n), which can be used in different installations (e.g. in aircraft, ship or ground installations)
- Systems, which consist of several components installed in different locations (e.g. the AN/USD-9 system has an airborne component AN/ARW-83 and a ground-based component AN/TSQ-105)

note 7: This designator was actually used. For example, the AN/CBQ-1 was an air-transportable pigeon loft & message center. The "AN" system, as originally devised, was intended for electronic and communications equipment. The US military used homing pigeons (on a small scale, of course) through WW II (the Army did not retire its last homing pigeon until 1957).

note 8: Type letter "E" (Laser) is a recent (1985) addition to the system and is not in wide use. Most laser devices use either "V" or "A", depending on the laser wavelength.

Components or Parts

Components and parts are designated as follows:

A one- or two-letter code indicates the type of the unit or group:
Group indicators:

• OA - Miscellaneous Group (only used, if no other indicator applies)
• OB - Multiplexer and/or Demultiplexer Group
• OD - Indicator Group
• OE - Antenna Group
• OF - Adapter Group
• OG - Amplifier Group
• OH - Simulator Group
• OI - Cryptographic Group
• OJ - Consoles and Console Group
• OK - Control Group
• OL - Data Analysis and Data Processing Group
• OM - Modulator and/or Demodulator Group
• ON - Interconnecting Group
• OP - Power-Supply Group (non-rotating types)
• OQ - Test Set Group
• OR - Receiver Group
• OS - Satellite Group (see note 1)
• OT - Transmitter Group
• OU - Converter Group
• OV - Generator Group
• OW - Terminal Group
• OX - Coder, Recoder, Interrogator, Transponder Group
• OY - Radar Set Group
• OZ - Radio Set Group (not used, if OE, OR or OT can be applied)

Unit indicators:

• AB - Support for Antenna ("antenna base")
• AM - Amplifier
• AS - Antenna, Simple and Complex
• (AT - Antenna, Simple; this unit designator has been removed from the system; now covered by AS)
• BA - Battery, Primary Type (non-rechargeable)
• BB - Battery, Secondary Type (rechargeable)
• BZ - Alarm Unit ("buzzer")
• C - Control
• CA - Computer Auxiliary Unit (like peripheral devices, etc.)
• (CA - Commutator Assembly; this unit designator has been removed from the system)
• (CB - Capacitor Bank; this unit designator has been removed from the system)
• CC - Cable Assembly, RF
• CD - Controlling Device
• (CG - RF Cable & Transmission Line; this unit designator has been removed from the system; now covered by CC)
• (CK - Crystal Kit; this unit designator has been removed from the system)
• CM - Comparator
• CN - Compensator
• CP - Computer
• (CR - Crystal; this unit designator has been removed from the system)
• CU - Coupler
• CV - Converter (Electronic)
• CW - Radome
• CX - Cable Assembly, non-RF
• CY - Case or Cabinet
• D - Dispenser
• DA - Dummy Load (electrical test loads)
• DI - Data Transmission Device
• DT - Detecting Head
• DU - Display Unit/Monitor (peripheral device for computers etc.) (see note 2)
• (DY - Dynamotor; this unit designator has been removed from the system)
• (E - Hoist; this unit designator has been removed from the system)
• F - Filter Unit
• (FN - Furniture; this unit designator has been removed from the system)
• FO - Fiber Optics Device
• FR - Frequency Measuring Device
• G - Power Generator (see also PU)
• GO - Goniometer
• (GP - Ground Rod; this unit designator has been removed from the system)
• H - Head, Hand or Chest Set
• (HC - Crystal Holder; this unit designator has been removed from the system)
• HD - Environmental Apparatus
• ID - Indicator Unit (non-cathode ray tube)
• (IL - Insulator; this unit designator has been removed from the system)
• IM - Intensity Measuring Device
• IP - Indicator Unit (cathode ray tube)
• J - Interface Unit ("Junction")
• KG - Key Generator
• KY - Keying Device
• LA - Laser
• (LC - Line Construction Tool; this unit designator has been removed from the system)
• (LM - Lamp; this unit designator has been removed from the system)
• LS - Loudspeaker
• M - Microphone
• (MA - Magazine; this unit designator has been removed from the system)
• MD - Modulator, Demodulator or Discriminator
• ME - Meter
• (MF - Magnetics or Magnetic Field Generators; this unit designator has been removed from the system)
• MK - Miscellaneous Kit
• ML - Meteorological Device
• MO - Multipurpose Unit
• MT - Mounting
• MU - Memory Unit
• MW - Microwave Device
• MX - Miscellaneous
• O - Oscillator
• OC- Oceanographic Device
• OS - Oscilloscope, Test (see note 1)
• (PD - Prime Driver; this unit designator has been removed from the system)
• (PF - Pole Fitting; this unit designator has been removed from the system)
• (PG - Pigeon Article; this unit designator has been removed from the system)
• (PH - Photographic Article; this unit designator has been removed from the system)
• PL - Plug-In Unit
• PP - Power Supply (non-rotating types)
• PT - Mapping or Plotting Unit
• PU - Power Equipment (rotating)
• R - Receiver
• RB - Robotics
• (RC - Reel; this unit designator has been removed from the system)
• RD - Recorder/Reproducer
• RE - Relay Assembly Unit
• (RF - Radio Frequency Unit; this unit designator has been removed from the system)
• (RG - Bulk RF Cable; this unit designator has been removed from the system)
• RL - Reeling Machine
• RO - Recorder
• RP - Reproducer
• (RP - Rope and Twine; this unit designator has been removed from the system)
• RR - Reflector
• RT - Receiver/Transmitter
• S - Shelter
• SA - Switching Unit
• SB - Switchboard
• SG - Signal Generator
• SM - Simulator
• SN - Synchronizer
• SS - Special Purpose Device
• (ST - Strap; this unit designator has been removed from the system)
• SU - Electro-Optical Unit
• SY - Secure Speech Device
• T - Transmitter
• TA - Telephone Apparatus
• TB - Towed Body
• (TC - Towed Cable; this unit designator has been removed from the system)
• TD - Timing Device
• TF - Transformer
• TG - Positioning Device
• TH - Telegraph Apparatus
• (TK - Tool Kit; this unit designator has been removed from the system)
• (TL - Tool; this unit designator has been removed from the system)
• TN - Tuning Unit
• TR - Transducer
• TS - Test Unit
• TT - Teletypewriter or Facsimile Apparatus
• TU - Television
• (TV - Tube Tester; this unit designator has been removed from the system)
• TW - Tape Unit
• (U - Audio and Power Connector; this unit designator has been removed from the system)
• (UG - RF Connector; this unit designator has been removed from the system)
• V - Vehicle
• (VS - Visual Signalling Equipment; this unit designator has been removed from the system)
• (WD - Cable, 2 Conductors; this unit designator has been removed from the system)
• (WF - Cable, 4 Conductors; this unit designator has been removed from the system)
• (WM - Cable, Multiple Conductors; this unit designator has been removed from the system)
• (WR - Waveguide; this unit designator has been removed from the system)
• (WS - Cable, Single Conductor; this unit designator has been removed from the system)
• (WT - Cable, 3 Conductors; this unit designator has been removed from the system)
• ZM - Impedance Measuring Device

The one or two letter code is followed by the model number.
Each unit or group indicator uses its own model number sequence, starting at 1. Blocks of high model numbers are reserved for use by Canada (5000-5999, 25000-25999), Australia (20000-20999), New Zealand (21000-21999) and the UK (22000-22999).

The optional suffix letter denotes a specific version of the equipment.
The first version uses no suffix, the first modifcation uses "A", etc. The letters "I", "O", "Q", "S", "T", "X", "Y", "Z" are not used as version suffix. "I", "O", "Q" and "S" could be confused with numerals 1, 0 and 5 respectively, for "T", "X", "Y" and "Z".

The full type designation of a group or unit includes a slant bar, followed by the designation of the set or system, of which it is a part.
If the equipment can be used with several systems, a more general designator is appended. E.g. the MD-945/TSC is a modulator, which is used with several AN/TSC-n systems, while the AS-22/AP is an antenna, which is used with several airborne radar sets/systems with different purpose indicators. A designation for a general purpose component, i.e. one that is not designed to be used in a specific environment, should use only the general installation letter "U" after the slant bar. However, the "/U" suffix is often omitted in these cases.
So the suffix "/URR" stands for General Utility / Radio  / Receiver.

The "(V)" symbol indicates an equipment (usually a group) with variable components. A number following the "(V)" is used to designate a specific version of the equipment, i.e. with a specific component configuration.

Notes:
Note 1: Group indicator "OS" was added to the system in 1998, and clashes with the "OS" unit indicator. These two designators apparently share a single numerical model number sequence.

Note 2: Unit indicator "DU" is not listed in the original MIL-STD-196E. It was added to the system around 1999 and will be included in the next revision of MIL-STD-196.

Many thanks to Andreas Parsch who runs an excellent website on U.S. military designations which was very helpful for me to understand the U.S. Army designations. He also lists all AN/Axx Airborne equipment, far behind the scope of our site.

Martin Boesch

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