The Fedora lister currently uses rpm://fedora/packages/$package_name as origin URLs, inspired by the Debian lister's deb://Debian/packages/$package_name and deb://Ubuntu/packages/$package_name URLs.
However, neither deb: and rpm: are standard which risks conflicting with future specs (or other non-standard uses), and in itself it's not great.
While it is (probably?) too late to change Debian origins, we need to make a decision before deploying the Fedora lister in production.