/PARENT_TABLE=table

    Requires either create (C) access to the parent table and write
    (W) access to the system directory or the SYSPRV privilege.

    Specifies the name of the parent table. The parent table
    determines whether a table is private or shareable; it also
    determines the size quota of the table. If you do not specify
    a parent table, the default table is LNM$PROCESS_DIRECTORY. A
    shareable table has LNM$SYSTEM_DIRECTORY as its parent table.
    The parent table must have the same access mode or a higher level
    access mode than the one you are creating.