The link you provide specifically states:
Quote:
iBooks now supports an extension to EPUB that allows publishers to create books with precise layout using CSS. This is Apple’s own extension, not part of the EPUB specification itself
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(Emphasis mine). Such books are not ePub files. I don't give a damn what some people may wrongly choose to call them. The whole point of ePub is that it is a published and ratified standard. Anything that doesn't conform to the standard cannot legitimately be called an ePub file. Standards conformance is not a "popularity context", but a simple technical matter. A file either conforms to the ePub standard, or it does not. These do not, and cannot legitimately be called ePub books.