The REQUEST_HANDLE SCOPE clause is only used by RDBPRE and RDML
    programs, not with RDO or RDB$INTERPRET. In a RDBPRE program
    where an RDO request occurs within a higher level language loop,
    the REQUEST_HANDLE SCOPE clause determines whether system or
    user request handles are set to zero in the RDO FINISH statement
    within the loop.

    The default is DEFAULT, where the values of the request handles
    are not set to zero when the RDO FINISH statement executes.