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

 handle
    A pointer to a client handle created by any of the client handle
    creation routines.
 procnum
    The procedure number associated with the remote procedure.
 inproc
    The XDR routine used to encode the remote procedure's arguments.
 in
    A pointer to the remote procedure's arguments.
 outproc
    The XDR routine used to decode the remote procedure's results.
 out
    A pointer to the remote procedure's results.
 timeout
    A structure describing the time allowed for results to return to
    the client. If you have previously used the clnt_control macro
    with the CLSET_TIMEOUT code, this value is ignored.