@ekZepp They’re sorta bridged in the sense that if you @ a lemmy community from other ActivityPub software it’ll post to the community. It’s the same protocol, though a different enough implementation that it acts a lot like a bridge. The first line acts as the title, then the rest of the post is the body.
@Lemminary Not sure where I initially heard it, but I think I just came across it randomly in a comment or blog. I’m sure somewhere is some docs there’s the info though. Tested it a while back though and confirmed it works.