Some examples of Kindle products that do not take AZW3:
- Some older Kindle devices, no longer sold new, but still in use by many people.
- The Kindle for iOS app. It requires AZK format instead of AZW3.
- The Kindle cloud service for personal documents and the Kindle self-publishing platform (KDP). These do not accept AZW3, but will take a master MOBI that includes AZW3 as part of it.