/host=* has something called "server" that is neither child nor attribute

Start a domain with a host called "master". In CLI, do /host=master/:read-resource. In the result, you will see a resource called "server".

However, if you do /host=master/:read-children-types it will not show up as a child type.

If you do /host=master/:read-resource-description it will not show up as an attribute either.

So what is "server"? It's not a child and it's not an attribute. Is it something that should not show up in read-resource?