While looking for posts with the #degoogle hastag with my mastodon account, I realized that mixed in the hastag timeline there were posts to the !degoogle@lemmy.ml community, but not containing the hastag itself in the text.
I tried to look around, but In wasn’t able to find an explanation of how this is supposed to work: is it because of the name of the community that is the same of the hastag? Or is or because the hastag is “embedded” in the community itself?
Edit: for those interested, the explanation is in this comment -> https://lemmy.world/post/39083486/20606028


Mmh, that’s not an explanation: when I look at an hastag timeline in mastodon, I expect to see all the posts that federate with my server and contain the relevant hastag.
In this case I for sure see also posts that are federated, but, AFAIK, do not contain the hashtag. The only element is the name of the community
According to the protocol they share (ActivityPub) communities and hashtags are essentially the same thing, they’re a grouping containing many posts. Typing out a hashtag is how you tell Mastodon to add your post to that “hashtag group” (and you can add your post to multiple hashtags). In Lemmy, the community you post in IS the group (and you can cross-post it to multiple communities). The result is the same. They’re the same thing, just different ways of connecting your posts into them, and displayed in very different ways depending on which part of the Fediverse you’re using.
The confusing part is that it didn’t work most of the time. This seems to be a very recent change. Before, and still now, you could only post to lemmy communities by tagging them with @. Now they federate back, but as hashtags.
Consider community names hashtags.