SS$_NORMAL         Normal successful completion.
    SOR$_DUP_OUTPUT    Output file has already been specified.
    SOR$_ENDDIAGS      Completed with diagnostics.
    SOR$_INP_FILES     Too many input files specified.
    SOR$_NYI           Not yet implemented.
    SOR$_SORT_ON       Sort or merge routine called in incorrect
                       order.
    SOR$_SYSERROR      System service error.