I don't think we're talking about the same thing. I understood that the conversation was about attesting that, for instance, googleusercontent.com was owned by

I don't think we're talking about the same thing. I understood that the conversation was about attesting that, for instance, googleusercontent.com was owned by the same entity as google.com so could share cookies. A) I don't see any way that the list included in browsers of public suffixes makes it possible to decide that google.com really owns googleusercontent.com. If it did, we would already be there and woudln't be discussing this. B) Who do you think makes the public suffix list in the first place, where do you think it comes from exactly?