The content provider sends the <cancel-message> element to the BlackBerry® Infrastructure. It cancels a previously submitted push request. The BlackBerry Infrastructure can cancel pending push requests; if the push request is still pending for one or more BlackBerry devices, the BlackBerry Infrastructure accepts the cancellation request. However, the BlackBerry Infrastructure does not attempt to recall data that was already delivered to the BlackBerry devices specified in the original push request.
You can include one or more <address> elements in the <cancel-message> element to indicate the BlackBerry devices for which you want to cancel the push request.
In a cancellation request, the <address> element is optional. If you do not include an <address> element, the request affects all BlackBerry devices associated with the corresponding push request.