Right, that
And that's also why I say there are no special divs—I could name those anything as long as I update the CSS to match, and they could well be spans as well. It's semantically correct to make it a div, but as some people can attest to, publishers don't always care about being semantically (or mostly) correct as long as the book mostly works. They aren't even strictly necessary divs, with a different CSS hack you could probably (not 100% certain) achieve the same result with no added tags.