/www.python.org">Python web site</a>), footnote references
(manually numbered <a class="footnote-reference brackets" href="#id6" id="id1">1</a>, anonymous auto-numbered <a class="footnote-reference brackets" href="#id9" id="id2">3</a>, labeled auto-numbered <a class="footnote-reference brackets" href="#label" id="id3">2</a>, or symbolic <a class="footnote-reference brackets" href="#id10" id="id4">*</a>),
citation references (<a class="footnote-reference brackets" href="#id16" id="id5">12</a>), substitution 