Summary of Military Nomenclature System

(Lifted mostly from « Reference Data for Radio Engineers »)

The « AN » system (now called the Joint Electronics Type Designation System or JETDS), consists of a name, followed by a type number.

A type designation assignment for equipment such as a definitive system, subsystem, center, central, set, etc., shall consist of at least an AN, a forward slash, a three-letter equipment designation, a dash, and a number. The three-letter designation is taken from Table 1.

Table 1: Set or Equipment Indicator Letters

1st Letter

2nd Letter

3rd Letter

(Type of Installation)

(Type of Equipment)


A Piloted Aircraft A Invisible light, heat radiation A Auxiliary assemblies (not complete operating sets used with or part of two or more sets or sets series) (INACTIVE)
B Underwater mobile, submarine B Pigeon B Bombing
C Air transportable C Carrier C Communications (receiving and transmitting)
D Pilotless carrier D Radiac D Direction finger, reconnaissance, and/or surveillance
E Nupac E Ejection and/or release
F Fixed Ground F Photographic
G General ground use (includes two or more ground-type installations) G Telegraph or Teletype G Fire control or searchlight directing
H Recording and/or reproducing (graphic meteorological and sound)
I Interphone and public address
J Electromechanical or inertial wire covered
K Amphibious K Telemetering K Computing
L Countermeasures L Searchlight control
M Ground, mobile (installed as operating unit in a vehicle which has no function other than transporting the equipment M Meteorological M Maintenance and/or test assemblies (including tools)
N Sound in air N Navigational aids (including altimeter, beacons, compasses, racons, depth sounding, approach, and landing)
P Pack or portable (animal or man) P Radar P Reproducing
Q Sonar and underwater sound Q Special, or combination of purposes
R Radio R Receiving, passive detecting
S Water surface craft S Special types, magnetic, etc., or combination of types S Detecting and/or range and bearing, search
T Ground, transportable T Telephone (wire) T Transmitting
U General utility (includes two or more general installation classes, airborne, shipboard, and ground
V Ground, vehicular (installed in vehicle designed for functions other than carrying electronic equipment, etc., such as tanks V Visual and visible light
W Water surface and underwater combination W Armament (peculiar to armament, not otherwise covered) W Automatic flight or remote control
X Facsimile or television X Identification and recognition
Y Data processing Y Surveillance (search, detect, and multiple target tracking) and control (both fire control and air control)
Z Piloted and pilotless airborne vehicle combination

Example: AN/VRC-12 is a radio communication set installed in a vehicle designed for functions other than carrying electornic equipment.

Or, by way of further example (from Nick England), an AN/WBW-1 would be a remote-controlled, underwater pigeon.

All groups, including commercial off-the-shelf equipment, are identified by a two-letter indicator from Table 2.

Table 2: Group Indicators

Indicator Family Name
OA Miscellaneous groups
OB Multiplexer and/or demultiplexer groups
OD Indicator groups
OE Antenna groups
OF Adapter groups
OG Amplifier groups
OH Simulator groups
OJ Consoles and console groups
OK Control groups
OL Data analysis and data processing groups
OM Modulator and/or demodulator groups
ON Interconnecting groups
OP Power supply groups
OQ Test set groups
OR Receiver groups
OT Transmitter groups
OU Converter groups
OV Generator groups
OW Terminal groups
OX Coder, decoder, interrogator, transponder groups
OY Radar set groups
OZ Radio set groups

Applicable equipment indicator letters (Table 1) follow the forward slash to indicate the potential of the group for multiple or peculiar application. Example: OE-162/ARC indicates an antenna for aircraft radio-communication equipment. Equipment indicators with a specific model number (e.g., OK-450/TRC-26) are used following the forward slash when the group is peculiar to specific equipment (e.g., AN/TRC-26) with no known potential for other use.

Unit indicators are listed in Table 3.

Table 3: Unit Indicators

Indicator Family Name Indicator Family Name
AB Supports, antenna OC Oceanographic devices
AM Amplifiers OS Oscilloscopes, test
AS Antennas, complex and simple PD Prime drivers
AT Antennas, simple PF Fittings, pole
BA Batteries, primary type PG Pigeon articles
BB Batteries, secondary type PH Photographic articles
BZ Alarm units PL Plug-in units
C Controls PP Power supplies
CA Commutator assemblies, sonar PT Mapping and plotting units
CB Capacitor banks PU Power equipments
CG Cable assemblies, RF R Receivers
CK Crystal kits RC Reels
CM Comparators RD Recorder-reproducers
CN Compensators RE Relay assemblies
CP Computers RF RF components
CR Crystals RG Cables, RF bulk
CU Couplers RL Reeling machines
CV Converters RO Recorders
CW Radomes RP Reproducers
CX Cable assemblies, non-RF RR Reflectors
CY Cases and cabinets RT Receivers and transmitters
D Dispensers S Shelters
DA Loads, dummy SA Switching units
DT Detecting heads SB Switchboards
DY Dynamotors SG Generators, signal
E Hoists SM Simulators
F Filter units SN Synchronizers
FN Furnitures ST Straps
FR Frequency-measuring devices SU Optical devices
G Generators, power T Transmitters
GO Goniometers TA Telephone apparatus
GP Ground rods TB Towed bodies
H Head, hand, and chest sets TC Towed cables
HC Crystal holders TD Timing devices
HD Environmental apparatus (heating, cooling, etc. TF Transformers
ID Indicators, non-cathode-ray tube TG Positioning devices
IL Insulators TH Telegraph apparatus
IM Intensity-measuring devices TK Tool kits
IP Indicators, cathode-ray tubes TL Tools
J Interface units TN Tuning units
KY Keying devices TR Transducers
LC Tools, line-construction TS Test units
LS Loudspeakers TT Teletypewriters and facsimile apparatus
M Microphones TV Testers, tube
MA Magazines TW Tape units
MD Modulators, demodulators, discriminators U Connectors, audio and power
ME Meters UG Connectors, RF
MF Magnets or magnetic-field generators V Vehicles
MK Miscellaneous kits VS Signaling equipment, visual
ML Meteorological devices WD Cables, two-conductor
MT Mountings WF Cables, four-conductor
MU Memory units WM Cables, multiple-conductor
MX Miscellaneous WS Cables, single-conductor
0 Oscillators WT Cables, three-conductor
ZM Impedance-measuring devices

The type designation for units having one end use consists of an indicator from Table 3, a dash, a number, a forward slash, and the equipment the unit is part of or used with. Example: the receiver portion of the AN/VRC-12 is identified as R-40/VRC-12. If the unit has multiple usage, only those indicators that are common or appropriate are included after the forward slash. Examples: A power supply, part of, or used with, the AN/VRC-12 and AN/VRC-19 would be identified as PP-50/VRC. A power supply, « part of » the AN/VRC-12 and « used with » the AN/VRR-40 would be identified as PP-60/VR.

The system indicator AN does not mean that the Army, Navy and Air Force use the equipment, but simply that the type number was assigned in the AN (JETDS) system.

The reader is referred to « Miscellaneous Data » in Reference Data for Radio Engineers for further details on the AN (JETDS) nomenclature convention.