TSEC-

Most U.S. government-approved communications security 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. 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)