Could lemmy be used as a private self hosted forum?
And could lemmy be used as a private forum were only registered users and whitelisted users can view, post and comment on the instance. This way you can have a private instance which only paid users of your group or club can join like many membership website forums have.
There is a BB forum frontend for Lemmy that replicates that phpBB forum style. Saw it mentioned in a few comments.