http://idpf.org/epub/30 or
http://idpf.org/epub/30/spec/epub30-...-20110506.html
Regarding examples, read Jon's answer in this thread of yours:
https://www.mobileread.com/forums/sho...d.php?t=165885
Harry, could you please tell us something about yourself, why you're asking all these epub-3-questions, what you're driving at... Thanks!