Let’s say:
- I am on instance A.
- I browse on a community that is on instance B
- a user from instance C post something on that community B.
Now i want to share a link to this post. Which instance should i pick?
- A my home instance
- B the community
- C the post author
When you post something, it is first posted to your own instance, then sent to the community, then the community sends it to its subscribers.
The authoritative source is always the one the originating user is from in ActivityPub.