Also, what about titlepage.xhtml and toc.xhtml?
I'm not sure if titlepage.xhtml is a standard part of an epub of if it's a calibre construct. But, for the book I'm currently editing, the HTML line is:
Code:
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-us">
Toc.xhtml gets built with the Editor's "Insert Inline Table of Contents" function. But, even after re-building that with changes made to the template as Karellen mentioned, its HTML line looks like:
Code:
<html xmlns="http://www.w3.org/1999/xhtml" lang="en">