Hi
@eschwartz
I am sorry to disagree again with your previous comment. In this precise context, the word
html does not mean the same thing: its meaning is related to the Doctype you use
<!DOCTYPE html> goes at the top of every
HTML5 page.
The HTML5 word <!DOCTYPE html> means "this page is written in HTML5" as opposed to, say HTML 4.01. (and its three different former Doctypes).
It may be useless for EPUB3 purposes, but it's different.