VMS Help TCPIP Services, Programming Interfaces, RPC Server Routines, svc_sendreply, Arguments  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 xprt
    A pointer to an RPC server handle created by any of the server
    handle creation routines.
 outproc
    The XDR routine used to encode the server procedure's results.
 out
    A pointer to the server procedure's results.