V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

MILNET
       MILitary NETwork (USA, mil., network)


The Free On-line Dictionary of Computing (30 December 2018):

MILNET

   Military Network.  Part of the Defense Data Network (DDN)
   and of the Internet.  Managed by the Defense Information
   Systems Agency (DISA).

   [Location?  Number of hosts?  Purpose?]