Copy/pasted from a previous response I wrote regarding this topic. I hope it helps:
When you follow a given account on #Mastodon with your #kbin account, posts from that account will be #federated here. If they use #hashtags, then posts they write will be federated into #magazines here based on permitted tags chosen by magazine moderators which show up in the #microblogging section of a magazine. AFAIK, posts that don't get sorted into a particular magazine will be sent to @random. In order to search for magazines/communities, you can enter [email protected] into the search bar for example.