tenforward.social is one of the many independent Mastodon servers you can use to participate in the fediverse.
Ten Forward is a fediverse server run by guinan aka packetcat aka Sadiq. It is for everyone who wants a strongly moderated community space to make their fediverse home in.
@testman@ilyess that must be it then. I follow a bunch of tags on masto. At least one of them is bound to line up with a community name on a Lemmy instance.
