Hi, just to share some thoughts, at GNU social, for v3, we’re planning on adding a logic layer of umbrella groups that we’ve elaborated a bit here: https://notabug.org/diogo/gnu-social/issues/186 . We haven’t got to a lot of implementation details yet as we’ve been busy with other priorities. But it seems that the rest of the world is already having fun with implementing Groups in ActivityPub and, since we really aren’t available enough to get into these implementation discussions at the moment, just wanted to share this here so that the others could start deliberating a bit about it as well. TL;DR: GNU social may need a property in the group actor indicating whether it is meant to be under an umbrella (as described in the linked issue) or not. Thanks. If someone else has already thought about this or came up with a better solution, sorry for bothering, we will eventually read about it when with time to implement this.