The <surface> element represents a page, or any other inscribed surface. An encoder can choose to encode a double-page spread as either a single <surface> or as two distinct <surface> elements each representing a single page. A <surface> element contains information about any rectangular regions of interest on that surface, and any graphics which depict it. A <surface> may bear attributes, which align it with particular areas of interest on that surface.

Contributed by Caroline. View changelog.