Finally, something that the book doesn't cover at all, but is critically important: Back.
Not sure how I missed this, as Cancel/Back/Escape even existed back in featurephone days as a key hardware button.
I also have good data on how much it is used, mostly from the web but semi-anecdotally the same is seen in apps and OSs.
Story: during user research a team I work with was testing an app. One of those where the developers just ported the iOS-designed hybrid app to Android, so it had things like the iOS back button in the corner and no binding to the OS back button. ZERO users found the iOS back button. You don't just have to provide the function, but provide it in the OS-expected manner.
I also have lots of notes, with illustrations, about the back stack, from a slideshow.
SO, if you run across this article and want more, tell me and I'll work on it.
ACTUALLY probably need to rename it Back and the Stack OR make that a separate section in some architectural discussion, this Back is just the on-screen button. http://www.uxmatters.com/mt/archives/2015/07/back-the-stack-and-authentic-design.php