I have sometimes seen that when the 'half title' page of a book (the page that goes before the title page) is left in blank (which is one of the possible alternatives), a message such as 'This page is intentionally left blank' is included in that page, in the PDF version of the book.
Do you agree with this practice? Do you recommend it?
I ask this because I actually left blank the half-title page in my book, and the PDF looks a bit strange, in the sense that many people is going to think that there is something missing or that one extra blank page was added by mistake.
On the other hand, I think that adding such a message in the PDF version actually breaks the intention of that blank page, which is, creating a blank space in the transition from the cover to the title page.
So, what is your experience, opinion, etc. about this matter?