Page left blank intentionally message on blank pages

TL;DR There are the "Blank right pages" / "Blank left pages" page types in the page set.

Extra details:

I've quickly shot a simple sample 🙂 video. No comments / subs - sorry for that, but it's pretty much self-explanatory.

Also attached the document showcased on the video.

It's the sample DITA bookmap (no topics included, but should work on any installation).

Works the same for other doctypes, of course.