IEN

from The Free On-line Dictionary of Computing (8 July 2008)

Internet Experiment Note
IEN

   (IEN) A series of reports pertinent to the {Internet}.  IENs
   were published in parallel to RFCs and are no longer active.

   See also {Internet-Draft}, {Request For Comments}.

   (1994-12-08)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

IEN
       Internet Experiment Notebook (predecessor, RFC)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

IEN
       Internet Engineering Notes