Just wrapped up a session at FediForum where @snarfed.org@fed.brid.gy and @quillmatiq@mastodon.social discussed FEP-fffd: Proxy Objects as a way to link disparate cross-network objects together.

I piped up that @rimu@piefed.social and I were working on similar problems with cross-posting, though we were discussing this well within the confines of ActivityPub — cross-posting between threadiverse communities

We hadn't come up with any path forward yet, but the FEP notes some properties that we could use.

• alsoKnownAs to refer to a canonical post?
• An url array to show cross-posts?