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

Border Gateway Protocol
BGP

    (BGP) An Exterior Gateway Protocol defined in
   RFC 1267 and RFC 1268.  BGP's design is based on
   experience gained with Exterior Gateway Protocol (EGP), as
   defined in STD 18, RFC 904 and EGP usage in the NSFNet
   backbone, as described in RFC 1092 and RFC 1093.

   (1994-11-29)