Comments on draft-ietf-idnabis-defs-10

[Paul Hoffman]

At 1:31 PM -0400 8/31/09, Vint Cerf wrote:
>Assuming conforming applications would reject both loookup and registration
>of any uppercase ascii then your conclusion seems valid.
>
>What do others think?

Both -defs and -protocol explicitly use case-insenstive matching for A-labels. Most developers reading those who implement Punycode like the implementation you used yesterday (that is, the Punycode implementation *also* lowercased output even though that is not in the RFC) will completely miss this subtlety.

Andrew, a developer who actually read the Punycode RFC, missed the subtlety.

Wil alerted the list months ago, and all of us still missed this subtlety.

It would be an act of absurd optimism to think that developers will get this without us being very explicit in both documents about what we mean.