Re: [dbound] The proposals before us

Gervase Markham <> Mon, 12 September 2016 13:30 UTC

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To: John R Levine <>, Casey Deccio <>
References: <20160910211314.47140.qmail@ary.lan> <> <alpine.OSX.2.11.1609102313420.53927@ary.lan>
From: Gervase Markham <>
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Date: Mon, 12 Sep 2016 14:30:35 +0100
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Subject: Re: [dbound] The proposals before us
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On 11/09/16 04:44, John R Levine wrote:
> Let's say you're looking up the domain bulgaria.xn--90ae.  That's a
> name in a real TLD, and the TLD doesn't appear in the PSL.  What does
> the code do now?  Looking at some of the PSL libraries, the results
> look pretty random.  Some raise exceptions, some fall off the ends of
> routines and return null or a random result.

The PSL algorithm states that if the suffix of a given domain name is
not in the PSL, then the public suffix is the last label - so "xn--90ae"
in your example. And the PSL+1, or "registered/registrable domain" would
be bulgaria.xn--90ae.

Whether this is always correct is a matter for discussion, and whether
libraries do this is a matter for their authors, but that's what the
spec says. See "Algorithm", bullet 2: