ref: 0d59a2358a2a1f93fb28cd7f47f8420fbf06a9af dir: /sys/lib/python/mercurial/templates/rss/header.tmpl/
<?xml version="1.0" encoding="{encoding}"?> <rss version="2.0"> <channel> <link>{urlbase}{url}</link> <language>en-us</language>