pandoc/test/command/4235.md

% pandoc --id-prefix=foo
This.^[Has a footnote.]
^D
<p>This.<a href="#foofn1" class="footnote-ref" id="foofnref1"><sup>1</sup></a></p>
<section class="footnotes">
<hr />
<ol>
<li id="foofn1"><p>Has a footnote.<a href="#foofnref1" class="footnote-back">↩</a></p></li>
</ol>
</section>