[registrars] John Klensin's view on Single-letter second level domains

["Bruce Tonkin" <Bruce.Tonkin@xxxxxxxxxxxxxxxxxx>]

-----Original Message-----
From: Liz Williams
Sent: Friday, 19 January 2007 6:31 PM
To: GNSO Council
Subject: [council] Fwd: Single-letter second level domains

Colleagues

Please find below a note from John Klensin which I received this
morning.  He has asked me to forward it to the list.

I will be speaking with John and Steve later today if their schedules
permit.

Liz
.....................................................

Liz Williams
Senior Policy Counselor
ICANN - Brussels
+32 2 234 7874 tel
+32 2 234 7848 fax
+32 497 07 4243 mob




Begin forwarded message:

> From: John C Klensin 
> Date: Thu 18 Jan 2007 19:26:34 GMT+01:00
> To: liz.williams
>
> Subject: Single-letter second level domains
>
> Liz,
>
> Your recent note to the GNSO Council about single-letter domains
> (http://gnso.icann.org/mailing-lists/archives/council/msg03148.html)
> and the attached report was just called to my attention.  I'm
> copying Steve Crocker on this note since the topic is very much
> a stability issue and not a provision for expansion or
> infrastructure one.
>
> The premise of the report, that the main reason for reserving
> single-letter names was to permit future expansion, is not
> correct.  That explanation is, instead, the consequence of a
> long-term, and oft-repeated, misunderstanding.  I've tried
> explaining this several time to a number of people and groups
> within ICANN including various senior staff, both of the
> previous IANA managers, and several of the members of the
> community who have been pushing for single-character
> registrations.
>
> The notion that single-character names should be reserved for
> expansion of the DNS derives from an almost offhand comment Jon
> Postel made many years ago.  The essence of the comment was
> that, given all of the confusion and problems that had been
> created by trying to associate TLDs with specific semantics, we
> would have been better off with TLDs named "b ... y" (reserving
> "a" and "z" for future expansion and because people might think
> they had special value).  When someone asked for a domain name
> at the second level, they would then be randomly assigned to one
> of those single-character TLDs.  A somewhat fanciful set of
> notes circulated for a while that elaborated on this idea.  That
> document never made it into formal publication although part of
> it inspired an alternative option for ENUM that also was never
> published.  It should be stressed that these ideas were more of
> the character of whimsical musings than serious proposals.  They
> were never considered as serious proposals even by their
> originators.
>
> In any event, that particular idea about DNS expansion would
> never have produced "Example.a.com".  It might have produced
> "example.com.b" (as mentioned above, "a" and "z" were, in that
> idea, permanently reserved) or, more likely, "example.d" or
> "example.cc.b".
>
> There was apparently an entirely separate and unrelated
> suggestion about reserving one-character labels at some level of
> the DNS for infrastructure use, much as subdomains of .ARPA are
> used today.   While I remember hearing about that idea, I think
> it was just a suggestion made during a meeting or conversation.
> As far as I know, the suggestion was never written down or
> explained, much less turned into a proposal that anyone
> considered or approved.
>
> The reason for the prohibition on single-character registrations
> was strictly a matter of identifier integrity and DNS stability.
> Specifically, it was intended to reduce the odds of false
> positive errors if a one-character typing error was made.  The
> prohibition on the use of underscore ("_") in domain names,
> given that hyphen ("-") was going to be permitted, was largely
> driven by very similar   considerations.  I believe that, had we
> realized that we would end up with millions of names in some
> TLDs and almost complete saturation of the two-character and
> three-character spaces in those TLDs, registration of
> two-character SLDs probably would have been prohibited as well.
>
> That reason has not changed.  If one permits (and encourages,
> which, in today's market, is much the same thing), single-letter
> registrations, it is safe to assume that all 26 labels will
> swiftly be populated (single-digit labels raise some additional
> issues because they are very easily used in certain types of
> tricky-syntax phishing attacks).   Anyone trying to use one of
> these labels and making a single-character mistake will almost
> certainly reach an unintended host.  In a world in which, for
> most users, simply opening a web page associated with an unknown
> site can be sufficient for virus infection, it is simply unwise,
> and IMO, not in the best interests of the Internet, for ICANN to
> consider relaxing the current rule.   But the reason has nothing
> to do with DNS expansion, infrastructure, or any other narrowly
> technical reason.
>
> Just as we try to learn and extrapolate from our experience with
> ASCII domain name labels to IDNs, we should also take advantage
> of our experience with IDNs to inform our decisions about
> possible changes to rules about ASCII labels.   When the example
> of the "paypal" domain (with Cyrillic "a"s) was widely
> publicized, one of the primary reactions in the user and
> observer communities was outrage that the various actors in the
> domain name environment (and the certificate-issuing
> environment) had permitted a registration whose obvious purpose
> was to make it easy for users to make a potentially nasty and
> identity-compromising mistake.  I don't believe we need that
> lesson again about single-character SLDs.
>
> Please forward this message as appropriate -- I don't believe
> that I can post to the Council list.
>
> regards,
>    john
>