I think Steven meant the rel=me backlink (as described here: https://aleph.land/users/gdr) to xmpp.org that'd prove they control xmpp.org domain thus they’re as official as they can be :)
Yeah, I thought you knew about it… check your own profile (maybe in private mode): https://x0f.org/@stevenroose it has GitHub link verified because on GitHub you’ve got a back-link to your x0f.org profile. (GitHub, Twitter, GitLab use rel=me links in profiles).
The idea is super-simple and it works very well :)
Fosstodon is an English speaking Mastodon instance that is open to anyone who is interested in technology; particularly free & open source software.