Format options:

       /DESCENDANTS
       /NODESCENDANTS (default)

    Specifies whether CDO deletes children. When you specify the
    /DESCENDANTS qualifier, and your field element is controlled,
    CDO deletes all children that are not also children of additional
    elements outside the area defined by your top collection. If the
    field is uncontrolled, CDO deletes all children that are not also
    children of any other elements.