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

ATIS
       Alliance for Telecommunications Industry Solutions (org., USA)


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

A Tools Integration Standard
ATIS

    (ATIS) An object-oriented interface to a
   set of services that allows the saving, accessing and managing
   of information in a common repository.  Developed by Atherton
   Technology and DEC, based on an extended version of the
   Software BackPlane, proposed as an industry standard.

   (1994-10-25)