Q3: What characters should be allowed in a revised IDNA2008 specification?

Paul Hoffman phoffman at imc.org
Wed Apr 1 19:43:59 CEST 2009

At 12:14 PM -0400 3/31/09, Vint Cerf wrote:
>Does the working group agree that the more restricted set of the 
>current IDNA2008 Tables document should apply once IDNA2008 is 


>What should be done about registrations that use characters 
>that would not be allowed under IDNA2008?

Nothing. They will naturally wither as IDNA2008 is adopted by software, in the same way that older protocols wither and better ones are deployed.

>Should there be a 
>transitional period of finite duration after which these registrations 
>will become invalid?

No. They will *always* be valid under the old protocol, and they will *never* be valid under the new protocol. There is no reason to blur this distinction.

>Should they be grandfathered somehow?


>If we 
>believe all future registrations should be restricted, how would such 
>grandfathered registrations be found if the IDNA2008 rules would 
>reject lookups of the disallowed characters?

They would be found if we promoted confusion, so let's not.

>A two-lookup scheme might solve this problem:
>1. lookup according to IDNA2008 rules (if disallowed characters are 
>present, go to step 2); if domain name record is found, return the 
>information. If not, go to step 2
>2. lookup according to IDNA2003 rules (permitting a broader range of 
>characters in the lookup process). If domain record is found, return 
>it, if not return "no such domain name"

Of course. And, as others have pointed out, this scheme creates more problems.

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