Any application or driver that needs to be notified upon a hot swap event, detected by the Hot Swap Engine, registers itself to the kernel-mode Messaging Mechanism. The registration process also includes the set of event criteria that are relevant to this application or device. For example, an application can be registered to receive notifications whenever a CompactPCI board with a vendor ID of 0x1234 is removed. Each registration call creates a separate linked list of events.

As of this point, every hot swap event that occurs and meets the predefined set of criteria, is added to the linked list and sent to the relevant subscriber.

After receiving a notification, the subscriber retrieves additional information from the linked list that was not included in the original notification. In the example above, after the application received a notification that a CompactPCI board with a vendor ID of 0x1234 has been removed, it retrieves additional information regarding its device ID and physical location.