|
As pdurrant wrote, Amazon produces KFX for older books by re-processing them. As the software the generates KFX has improved, more older books have come to support Enhanced Typesetting, without any changes by the publisher.
The same situation can also come about in newer books if a publisher uses Amazon's Kindle Create software. That produces KFX directly and then Amazon generates MOBI, but not KF8, from that as a fallback for devices that do not support Enhanced Typesetting.
|