It isn’t documented anywhere that I can find, but Benjamin Smedberg’s handy Mozilla Status Board tool parses status text as Markdown, which is how I added a Didn’t header to the Done section of my status update with all the things I planned to do last week but didn’t make happen. (The Done, Next, and Coordination headers are all H4s, so I prepended four hash marks to #### Didn't to make it the same size).
(Note that [Markdown-style links](http://daringfireball.net/projects/markdown/basics) don’t work and cause the entire section in which they appear to remain unparsed. However angle-bracketed URLs, as recommended by RFC 3986 <http://labs.apache.org/webarch/uri/rfc/rfc3986.html#delimiting>, work when added to the ends of lines. And “bug ###” references are auto-linkified.)
FWIW, I think this is the code for the app, and this looks like the change that falls back to unparsed text when parsed text fails sanitization, which apparently is the case for Markdown-generated links.