Any string entered at the RDO> prompt is saved in the recall
    buffer. This includes all DCL commands prefaced by the dollar
    sign ($), commented text that begins with the exclamation
    point (!), and any RDO statements. The carriage return delimits
    each line written to the recall buffer. Thus, in the following
    example, four separate entries are written to the recall buffer:

    RDO> FOR E IN EMPLOYEES
    cont> WITH E.EMPLOYEE_ID BETWEEN "00164" AND "00175"
    cont> PRINT E.LAST_NAME, E.EMPLOYEE_ID
    cont> END_FOR

    The most recently typed command is at the top of the recall
    buffer. If the user enters CTRL/B at this point, the END_FOR
    statement would appear first.

    There are no parameters or logicals available to control the
    maximum number of lines saved in the recall buffer.