MVALID (was Re: M-Label or MVALID, and dangers with mappings?)

[Paul Hoffman]

At 12:54 PM -0400 4/13/09, Andrew Sullivan wrote:
>On Sun, Apr 12, 2009 at 02:34:24PM -0500, Pete Resnick wrote:
>> If we're going to deal with mappings, I want it to be a separate
>> document.
>
>I like that suggestion.  It seems to me to enforce the separation of
>"here's the definition of IDNA2008" and "here are some things to make
>IDNA2008 work well with other stuff".

Andrew and Pete: do you feel that it is OK for this WG to update a protocol from one where a conformant application was required to convert "EuroCafé.com" to a valid DNS request to one where a conformant application can simply reject that input? Note that there is no indication to the user which version of the protocol is being used.

You are both fine with that? As you can tell, I am not. I think it is fine for the protocol to reduce the characters that are allowed; I think it is fine to change some characters mappings when done carefully. I think it is not fine to make a mapping that is commonly done by billions of people and silently remove it from the protocol.