What do people use public suffix for?

[jra at baylink.com (Jay Ashworth)]

----- Original Message -----
> From: "John Levine" <johnl at iecc.com>

> The public suffix list contains points in the DNS where (roughly
> speaking) names below that point are under different management from
> each other and from that name. It's here: http://publicsuffix.org/
> 
> The idea is that abc.foo.com and xyz.foo.com have the same management,
> but abc.co.uk and xyz.co.uk do not.
> 
> You don't have to tell me that it's a gross crock, but it seems to
> be a useful one. What do people use it for? Here's what I know of:
> 
> * Web browsers use it to manage cookies to keep a site from putting
> cookies that will affect other sites, e.g. abc.foo.co.uk can set a
> cookie for foo.co.uk but not for co.uk.
> 
> * DMARC (www.dmarc.org) uses it to find a policy record in the DNS
> that describes a subtree, e.g., if you get mail that purports to be
> from eBay at reply1.ebay.com it checks the policy at ebay.com.
> 
> What other current applications are there?

Seems to me that it's a crock because *it should be in the DNS*.

I should be able to retrieve the AS (administrative split) record 
for .co.uk, and there should be one that says, "yup, there's an
administrative split below me; nothing under there is mine unless 
you also get an exception record for a subdomain".

The people who know authoritatively that their subdomains are within
someone else's administrative span of control *are the people who own
those domains*.

No?

Cheers,
-- jra
-- 
Jay R. Ashworth                  Baylink                       jra at baylink.com
Designer                     The Things I Think                       RFC 2100
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