trentm/python-markdown2 — pull request #156 by malcolmr (2014-03-25 17:08:05+00:00)
Title: Footnotes: use a numeric character reference rather than a named entity.

` ` is valid HTML, but not (usually) valid XML, which causes problems when e.g. generating content to be included in an Atom feed. In contrast, ` ` is valid in all contexts.