----- Original Message -----
From: "John Levine" <johnl@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@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@baylink.com Designer The Things I Think RFC 2100 Ashworth & Associates http://baylink.pitas.com 2000 Land Rover DII St Petersburg FL USA #natog +1 727 647 1274