Following up on davidfor's suggestion that the backlinks are not actually required for footnotes to pop-up in kepubs. My earlier suggested footnote HTML coding can be simplified to:
After v2 - main body HTML (ie ch1-2.xhtml):
Code:
<p ...>some text<a href="ch2.xhtml#fn1" class="a">[1]</a></p>
After v2 - footnote HTML (ie ch2.xhtml):
Code:
<div id="id49">
<div class="title1">
<p class="p"><a id="fn1">1</a></p>
</div>
...
</div>