Posted late last week, the guidelines (PDF) detail all the intricate parts of the Kindle ebook format, and they explain how to make an ebook which will be accepted by Amazon. The Kindle Publishing Guidelines had previously been updated in October and February 2016, each time changing to reflect Amazon's new standards.
For reference, you can find a copy of the previous guidelines in the Wayback Machine (PDF).
This time around, for example, the guidelines no longer mention how to set a start location. (When making a Kindle ebook, you can set the ebook to turn to a specific location when opened for the first time.) Amazon also updated a few dozen different sections with better instructions or clarifications, and they also made this one small change:
- Changed "e-Ink" references to "E-reader" throughout
All of a sudden the guidelines now refer to "e-reader devices" rather than "e Ink devices".
This might be an indicator that Amazon plans to release a Kindle with a Liquavista screen like the one I announced as a joke last April Fool's Day, or it might signal that Amazon is thinking of expanding distribution beyond Kindles.
Or, and here is the most logical option, this change might reflect the tastes of the new Amazon employee who was just put in charge of the guide.
It's really too early to say at this time, but we should know more in a few months.