EpubEmbed
An element that embeds a web document on an EpubPage: an inline frame, or an object whose type is HTML or XHTML (#40). The page paints the embedded document in the box when it is a document of the book (#528, #612), and else an object's fallback. An app can place a web view of its own over rect for a URL outside the book, which the page does not show.
Each box stays on one page, as an image does: one that does not fit what is left of a page moves whole to the next (#41). Only an object taller than a page goes on from page to page.
Properties
the zip path of the embedded document, as EpubDocument.resource reads it, or a URL with a scheme. Empty when the element names no document.
the box in display space, y down, with the smaller y in KiteRectangle.bottom, as EpubLink.rect is. For an object that goes on to the next page, the part on this page.