Requires SYSNAM (system logical name) privilege to create an
    executive-mode logical name.
    Creates an executive-mode logical name in the specified table.
    If you specify the /EXECUTIVE_MODE qualifier and you do not have
    SYSNAM privilege, the DEFINE command ignores the qualifier and
    creates a supervisor-mode logical name. The mode of the logical
    name must be the same or less privileged than the mode of the
    table in which you are placing the name.