Source : Free On-Line Dictionary of Computing

X.12
     
         The American equivalent of UN/{EDIFACT} and various
        other national and industry {EDI} messaging {protocols}.  The
        first {Y2K ready} version of X.12 is version 4010.
     
        [What's "UN"?  Details?  Differences from EDIFACT?]
     
        (1999-09-10)