Picture Book Support
New features have been added to support how a book displays when a customer opens a fixed layout (picture) book. Fixed-layout books require that a display option be set to indicate the EPUB has a fixed layout ("fixed-layout"=true). See Text Directions for instructions. Other display options for fixed-layout books specify if the EPUB should open to a two-page spread, and open in portrait or landscape orientation. Display options can be specified by platform (iPad and iPhone/iPod touch).
Embedded Font Support
EPUBs can now use embedded fonts, in addition to the already-supported system fonts. If you want to use embedded fonts, you must specify that the EPUB contains fonts. Otherwise, the embedded fonts will not be respected, and user-specified fonts will be used instead.
Navigation Support
In the OPF .opf file, the <spine> element is used to indicate the linear reading order of the content. When the person reading the book uses “next page” navigation, the pages are displayed based on the spine order. If a spine item is auxiliary to the main flow of the book (for example, an answer key in a textbook), you can use the optional linear attribute set to no to skip over the item to avoid disrupting the reading flow.
Page Break Support
In standard, flowing EPUBs, you can use the CSS properties page-break-before and page-break-after to add page breaks before or after an element. See Presentation and Styling.