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

PRMD
       PRivate Management Domain (X.400, MHS)


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

primary management domain
PRMD

    (PRMD) The component of an X.400 electronic
   mail address that gives the organisation name, usually
   abbreviated to p= in written addresses.

   See also ADMD.

   (2003-05-15)