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

DECUS
       Digital Equipment Computer Users Society (org., DEC, user group)


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

Digital Equipment Computer Users Society
DECUS

    (DECUS) A world-wide organisation of Information
   Technology professionals interested in the products, services,
   and technologies of Digital Equipment Corporation and related
   vendors.  Membership in the US chapter is free and provides
   participants with the means to enhance their professional
   development, forums for technical training, mechanisms for
   obtaining up-to-date information, advocacy programs and
   opportunities for informal disclosure and interaction with
   professional colleagues of like interest.

   DECUS Home (http://www.decus.org/).

   (2014-08-26)