Kinda, it's a slight variation of that from what I can tell. E.g. you can't go and register john.smith.uk because it's arbitrary.fixed.fixed rather than arbitrary.arbitrary.fixed. You can do something like john.smith.co.uk, but only if you have registered smith.co.uk or they delegate to you.

It's an odd concept. I have to say I hadn't really thought of it before reading this.