Let’s say I’m from instance A and use a community from instance B. Let’s say another user of instance C, that’s not federated with A but is with B, post in B. Can I see that post?
Let’s say I’m from instance A and use a community from instance B. Let’s say another user of instance C, that’s not federated with A but is with B, post in B. Can I see that post?
Every post and comment is initially hosted on the user’s local instance. From there, it is federated everywhere else. If you’re on lemmy.ml and post on a community in lemmy.world, then if you click the federated link (multicoloured weird shape icon) it will take you to the lemmy.ml version of the post.
Thus, if your instance is not federated with another, you won’t see any posts or comments from users of that instance.
What’s really annoying is the way that they use a unique ID number for every post and comment - each instance makes its own. So you can’t just change the URL to your instance to find a specific post or comment. That only works at the community level, where the link becomes
yourinstance/c/community@theirinstance. What we should have is consistent numbering with the same instance tag, so a lemmy.ml post would belemmy.ml/post/12345, while others would belemmy.world/post/12345@lemmy.ml. Lemmy is still very much a work in progress.