OpenVMS usage:cond_value
    type:         longword (unsigned)
    access:       write only
    mechanism:    by immediate value

    Longword value returned as a status code. It is generally a
    success code, because all OpenVMS RMS errors should be signaled.
    The signal should include the file name and both longwords of the
    RMS status. Any errors detected within work I/O can be indicated
    by setting status to an error code, which will be returned by the
    EDT$EDIT routine.

    The condition value is returned in R0.