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

DECNET
       Digital Equipment Corporation NETwork (DEC)


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

DECnet

   A proprietary network protocol designed by Digital Equipment
   Corporation.  The functionality of each Phase of the
   implementation, such as Phase IV and Phase V, is different.