protocol

protocol n.  As used by hackers, this never refers to
   niceties about the proper form for addressing letters to the Papal
   Nuncio or the order in which one should use the forks in a
   Russian-style place setting; hackers don't care about such things.
   It is used instead to describe any set of rules that allow
   different machines or pieces of software to coordinate with each
   other without ambiguity.  So, for example, it does include niceties
   about the proper form for addressing packets on a network or the
   order in which one should use the forks in the Dining Philosophers
   Problem.  It implies that there is some common message format and
   an accepted set of primitives or commands that all parties involved
   understand, and that transactions among them follow predictable
   logical sequences.  See also {handshaking}, {do protocol}.