Now, as far as I know, this use of the UUID does not cause any major issues with the retailers, and will not lead to your EPUB being rejected. But it does not make sense to identify an EPUB with an ID that is not the ISBN. Future-proofing your content is one of the most important steps you can take as a production specialist.

EPUB CFIs are also a key part of the answer for how to share bookmarks, highlights, annotations and other reader-definable features between reading systems and between readers. By standardizing the referencing mechanism, it ensures that any reading system will be able to correctly dereference the location referenced by these CFIs, avoiding proprietary solutions to the same problem. (But, for true interop, a standard means of structuring the information for sharing is still necessary.)

Substrings in brackets are extensible assertions that improve the robustness of traversing paths and migrating them from one revision of the document to another. These assertions preserve additional information about traversed elements of the document, which makes it possible to recover intended location even after some modifications are made to the EPUB Publication

Our current integration with Hypothesis is nearly two years old now and the interface needs rethinking and updating. Sliding panels coming in from both side aren’t ideal and obscure content. The design too closely mimics a printed book and as a result the paginated rendering hinders being able to make annotations across pages. A scrolling view would allow navigating the book and using the Hypothes.is toolbar at the same time. We’re going to create a new example reader with the controls, navigation and Hypothes.is integrated together with scrolling text.

Modern science has proved that the fundamental traits of every individual are indelibly stamped in the shape of his body, head, face and hands—an X-ray by which you can read the characteristics of any person on sight.

But what most puzzled and confounded you was a long, limber, portentous, black mass of something hovering in the centre of the picture over three blue, dim, perpendicular lines floating in a nameless yeast.