The CHANGE CONTEXT command modifies a context by performing a
    change in place. CDO changes the values you specify, and other
    values remain the same.

    Because a context is a nonversioned element, CDO does not accept
    a branch designation or a version number in the context name.

    The TOP clause redefines the top collection property for the
    context. An error occurs if you attempt to redefine the top
    collection while you have any element reserved to your context.
    The SHOW CONTEXT or SHOW RESERVATIONS command indicates whether
    this condition exists.

    The NOTOP keyword sets the top collection property to a null
    value.

    The DEFAULT_ATTACHMENT clause redefines the default attachment
    property for the context. This property refers to the default
    behavior that occurs when you issue the UPDATE command. Choose
    one of the following keywords:

    DEFAULT_
    ATTACHMENT
    Keyword          Behavior

    SPECIFIC_        Does not detach the currently attached version.
    VERSION

    LATEST_CHECKIN   Detaches the currently attached version and
                     attaches the most recently checked in version.

    LATEST           Detaches the currently attached version and
                     attaches the lastest version, whether it is
                     checked in or is a ghost. The LATEST keyword is
                     the default.