Originally Posted by HarryT
Calibre calls it "AWZ3"; it's the same thing. Also, make sure that you go to the device interface configuration in Calibre, edit the Kindle interface, and enable the "AWZ3" check box so it'll send KF8, rather than Mobi, to the Kindle.
Hmm, I don't find "device interface configuration" in the preferences of calibre. Where am I supposed to find it?
Edit : ok found it when I reconnected my kindle. There I can see device in the toolbar and I can get to configuration.
I converted my books to AWZ3 and it seems to work. Thanks for the info!