@PieterPeach @taylorlorenz @Lxtruong instance owners can add Elasticsearch which would allow for full-text indexing and search for federated posts known to the instance.
There's a financial cost so if you're on an instance that some method to recoup costs, I'd reckon more easy to add.
@Lxtruong @taylorlorenz @PieterPeach nod. I don't know the intentions of the Mastodon developers but the search functionality now seems totally a technical limitation. Kinda like search on a WordPress site. By default it is horrible because of lack of full index in MySQL for the posts.
Throw on ES and it's a ton better. Just with the added work, cost, maintenance of ES being on the server now.
When you hit post the text goes off to your local instance that has to decide what to do with it. If it is Public it will be sent to every instance where someone follows your account as well as the instances of account you have tagged (e.g. if you respond to a post). Your post will also be added to your local feed and the Federated feed of each instance.
Unlisted is a request not to put a post in the news feeds. It goes to all the same placed as public, but doesn't end up places like Home, Local, or Federated (a nice thing to do for posts that only make sense as part of the thread they are in)
Followers asks that servers only make the post available to people who follow you. In conjunction with locked accounts this gives some measure of control, but you are dependent on the good faith of other instances for this privacy.
Direct is just like any other post, but it is sent only to the server of the recipient(s) with instructions to share it only with those users. Again you are totally dependent on the good faith of the instances to honor this request.
Some instances like mine also have a Local option which not let the post go beyond your local instance. If you have a local instance that is a safe space for you, you can use Local visibility and know that only people on your own safe instance will ever see it.