Is there such thing as a private community on Lemmy?
Is there a setting anywhere for moderators to take a community private (to make the posts, comments and other data visible only for people who are subscribed)?
If so, how does the mechanism work for finding and/or subscribing to private communities?
I have no idea how "Reddit + Fediverse" (i.e. Lemmy) works in terms of federating, but on Reddit, all you had to do was select an option to set your subreddit to private (only visible to subscribers).
It seems strange if Lemmy doesn't have a similar feature, for example, if you run a niche community and don't want random people giving unwelcome, ignorant, malevolent, etc. opinions. Also, in case Lemmy ever has enough users to be prone to "brigading" (groups ganging up on a community to downvote everything, harass subscribers, etc.), a "private" option seems like a basic and necessary feature.
You'll have to keep in mind that every "basic" feature needs to be made by "someone".
Features don't just pop into existence, just because they're needed.
All the work being done by the devs at the moment, is "necessary", and as they can only do so much, some "necessary" things will have to wait until other "necessary" things are done.
I'm guessing that's not really possible by design, since a subscriber from a remote instance automatically means their instance has to mirror all content from your community. It's not possible (AFAIK) to make a community available to just one user of a remote instance; at least the admin will always see the mirrored content.
Aside from that, it's also not possible to authenticate a remote user.
Exactly. The mechanisms needed to implement it are there, but I don’t think the devs are interested in much more than making it more stable and robust right now.