PPN

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

PPN

   Project-Programmer Number.

   A user-ID under {TOPS-10} and its various mutant progeny at
   {SAIL}, {BBN}, {CompuServe} and elsewhere.  Old-time hackers
   from the {PDP-10} era sometimes use this to refer to user IDs
   on other systems as well.

   [{Jargon File}]

   (1994-11-18)

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

PPN
       Project Programmer Number

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

PPN
       Public Packet Switching