Other rules can run these Actions

In rule machine I can Define an Action. I think I am supposed to be able to use these actions elsewhere, but I can not seem to figure out how to do it.
Suppose I Define a simple action to send a notification.

How do I access this in a rule?
i am sure I am missing something obvious, but I just can't quite get there.


It is listed under 'Set Private Boolean, Run/Stop/Pause Rules'.