The Tri-Service system was first enacted on 6 July 1962 by the DoD Directive 4505.6 "Designating, … See more

The system uses a Mission-Design-Series (MDS) designation of the form:
(Status Prefix)(Modified Mission)(Basic Mission)(Vehicle Type)-(Design Number)(Series Letter)
Of these co… See more

Since the 1962 system was introduced there have been several instances of non-systematic aircraft designations and skipping of design numbers.
The most common changes are to use a number fro… See more

Since 1939, a 2-letter manufacturer's code has been added to designations to identify the manufacturer and the production plant. For example, F-15E-50-MC, the "MC" being the code for the McDonnell Douglas plant at St. Louis… See more

In 1941, block numbers were added to designations to show minor equipment variations between production blocks. The block number appears in the designation between the model suffix and manufacture… See more