We currently use vanilla Markdown (via this package: https://github.com/waylan/Python-Markdown/)
This package supports a lot of Extensions: https://github.com/waylan/Python-Markdown/wiki/Third-Party-Extensions
We might at least want to have decent URL to Link conversion (via? http://github.com/r0wb0t/markdown-urlize)
This would be useful in cases like the reason field of the reports page http://critiquebrainz.org/reports/
or We could just use some other package to have the entire Github Flavored Markdown.