In ‘official’ documents, blank pages are used to ensure the printed format of the document makes sense. Books usually have chapters that start on the “right” page of a book, or you may have an appendix or index that needs to start on its own page.

When this need arises, the publisher will insert a blank page into the document, shifting everything to its proper place. In most places, you never notice.

To make sure you don’t think you’re missing a page, or something didn’t get printed, the publishers started inserting this text into the document:

This text ensured the reader and security checkers knew they got all the pages, and they didn’t miss any content!