Format options:

       /CLOSURE=keyword
       /NOCLOSURE (default)

    Specifies whether CDO unreserves additional elements. An
    unreserve operation fails if any element is a child of an element
    outside the area defined by the /CLOSURE qualifier.

    The /CLOSURE qualifier takes one of the following keywords:

    CLOSURE
    Keyword      Behavior

    TO_BOTH      Unreserves the element specified and all parents and
                 children.

    TO_BOTTOM    Unreserves the element specified and all children.

    TO_TOP       Unreserves the element specified and all parents.

    If you specify TO_BOTH or TO_TOP, CDO ignores parents above the
    top collection.