NextCloud / ownCloud have federation but the WebDav links are described in /.well-known/. I haven't installed Mastodon so I can't speak to it, but since WebFing

NextCloud / ownCloud have federation but the WebDav links are described in /.well-known/. I haven't installed Mastodon so I can't speak to it, but since WebFinger uses /.well-known/ I would be surprised if Mastodon did anything else[1]. [1]: https://tools.ietf.org/html/rfc7033#page-8 https://tools.ietf.org/html/rfc7033#page-8