Shutdown Notification

[bertabcd1234]

There is no such event or "notification." Here is the explanation, with ideas for workarounds:

Request for two additional location events

I think you are presuming that there is any time available to do anything when these happen. As it stands now, the reboot or shutdown begins immediately, and it is too late to send an event or respond to an event. I doubt that delaying these actions would be a particularly good thing to do. Both of these are user initiated commands, so surely the user can do something else prior if need be.

There is an event for system start, as you may already know.