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

    Releases memory allocated for the data structure to which objp
    points. The pointer passed to this routine is not freed, but what
    it points to is freed (recursively). Use this routine to free
    decoded data that is no longer needed. Never use this routine for
    encoded data.