Domain names with leading digits (Re: Determining the basic approach)

Harald Tveit Alvestrand harald at
Mon May 5 17:45:20 CEST 2008

Paul Hoffman skrev:
> At 7:48 AM +0200 5/5/08, Harald Tveit Alvestrand wrote:
>> I THINK, but do not know, that what Paul means by:
>>   11.  Make some currently-legal, non-IDNA labels illegal
>> . . .
>> And the resulting rule is:
>>   o  The first character may not be an EN (European Number) or an AN
>>      (Arabic Number).
> Correct, in part (see below). This rule prohibits thousands of current 
> domain names like,, and a whole lot of 
> others. It could be changed to be a registry recommendation instead of 
> a prohibition on all labels, even ones that don't appear in IDNs.
As currently specified, it would require to insert an extra, 
non-numeric domain before they inserted a RTL name: would 
be OK, but would not be. It's not a prohibition on "all 
labels" in the text you deleted above, but I'm pretty sure I didn't 
manage to get this clear & consistent in all places in the current 
version of the document.

Registry recommendations' powers tend to peter out extremely fast with 
distance from the registry.
>> I don't know of any other part of the idnabis work that affects 
>> LDH-compliant labels.
>> (There's also the minor point of codifying the existing prohibition 
>> against leading and
>> trailing hyphen, but that's a stretch of the term "currently legal". 
>> If that was intended,
>> please holler.)
> There is a second place. In draft-klensin-idnabis-issues-07.txt, 
> section prohibits labels that have a hyphen in positions 3 
> and 4 unless they are A-labels. This is completely unnecessary.
This prohibition was made by ICANN in order to prevent speculation 
against prefixes in the time period before IANA announced the selection.

As long as we never have to change the prefix, or introduce a second 
prefix for another purpose, it is unneccessary. How much do you want to 
bet that it will be?


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