Most U.S. government-approved, in communications security (COMSEC) equipment has designations in the form TSEC/KG-99, in which TSEC/ (note slash) is purely an identification for a designation system, not an abbreviation. The designation system is under the control of the National Security Agency (NSA). It complements the AN- system used for general military electronics, which does reserve certain of the letters in the AN/ system are reserved for NSA use.
While the designation system codes are quite complex and still contain special cases, the basic structure is:
- First letter: What is its function?
- Second letter: What information or physical materials does it process?
- Optional third letter: What kind of component is it?
The next numbers indicate a main model number within the series, followed by a bewildering and inconsistent set of version levels, alternate configurations, etc. Sometimes, what may seem an incremental improvement gets an entirely new model number, while a radical change may get a version change only. In other words, grasp the general principles of the system, but know that you will have to examine a specific system to understand its designation nuances.
- TSEC/KG-13 is a cryptographic key generator (code name PONTUS)
- TSEC/KY-57 was a cryptographic speech encryptor (code name VINSON)
- TSEC/KW-7 was a cryptographic key encryptor for asynchronous character data (i.e., "Teletype") (code name ORESTES)
Designation system codes
|B||-||-||Base of cabinet|
|D||-||-||Drawer or Panel|
|E||-||-||Strip or Chassis|
|F||-||-||Frame or Rack|
|G||General purpose||Key generation||-|
|I||-||Data transmission||Translator or Reader|
|M||Manufacturing||-||Memory or Storage|
|S||Special purpose||Special purpose||Synchronizing|
|T||-||Testing, checking, maintenance||Transmitter|
|V||-||-||Removable communications security component|
|W||-||Teletypewriter||Logic Programmer or Programming|