Reading this just gave me an interesting idea, when you start to post a link that's already been posted in another linked instance, it will start to show you that it's been posted elsewhere to different communities in other instances (on Lemmy, I don't know about Kbin). This clearly shows there's functionality there to look around when posting links, so I wonder if similar could be implemented when creating communities.

If the interface told you ahead of time that the community you were about to create has already been created in other instances, you wouldn't be prevented from going ahead & creating your own version, but you'd be more readily aware. Honestly a win-win approach imo, considering it would help you find a community you may have been looking for but didn't think existed, and it doesn't keep you from trying to make your own anyway.

couldn't have put it better myself (also a USENET oldie but w/o the beard)

It’s not about allowing a single instance to own the name. The name would belong to the federation in a global namespace.

A possible scenario is to define multiple namespaces. Each namespace can be local to a single instance, or shared between many. Within each namespace, a single community name is unique.

In this model, each instance would have a namespace that it owns, and the ability to participate in many others.

The trick is in how we name the namespaces and communities. We could do this the USENET way and do something like ., so beehaw.gaming vs. global.gaming. There are other models that could work too.