If the book contains endnotes, you'll need to add in a Heading 1 tag called "Endnotes" at the beginning of the Endnotes section (after the Level tag).

<level1>
     <h1>Endnotes</h1>
     ...

The Word-to-XML conversion process will insert an extra note reference into the text. This needs to be removed from the XML file:

<noteref idref="#endnote-0" class="Endnote">0</noteref></p>