I’ve seen this mentioned a few times already: people wondering why certain communities don’t show up in their instance. You need to first search for that community via the magnifying glass icon and type in “!communityname@instance.domain”
Notice the exclamation mark at the beginning. Might take a few seconds. This will teach your instance about the remote community.
Sweet! I would be interested, and might be able to help test. Let me know if something comes of it.
Nice, I got it working with this type of mention !communityname@instance.domain. But I want to see if I can convert the link form too, I will probably make a post once is done.