Originally Posted by brunobruno
Which additional requirements might couse a problem?
For starters you need a special file not required for ePub 3. The file is META-INF/com.apple.ibooks.display-options.xml
This is not the first time Apple has required a special file. They also need one for embedded fonts. Of course the content of these extra files must meet their requirements.
Apple does not specify that the ePub be version 3.0 so it is likely that an ePub 2 formatted file can have fixed layout and it is not clear if the features of a 3.0 would be supported.