In this post you can find pointers to documentation and source code for the pandoc2rfc package.

Pandoc2rfc source code:

github.com/miekg/pandoc2rfc, if you are not using the shell script (pandoc2rfc), you should just copy transform.xsl and perform the conversions manually (see documentation pointers below)

Packages:

for both xml2rfc and pandoc2rfc can be found at launchpad, these can probably also be installed on Debian and definitely on older Ubuntu versions.

Documentation:

This draft is the canonical documentation.