The standards for Internationalized Domain Names in Applications
(IDNA) require a review of each new version of Unicode to determine
whether incompatibilities with prior version or other issues exist
and, where appropriate, to allow the IETF to decide on the trade-offs
between compatibility with prior IDNA versions and compatibility with
Unicode going forward. That requirement, and its relationship to
tables maintained by IANA, has caused significant confusion in the
past. This document makes adjustments to the review procedure based
on experience and updates IDNA, specifically RFC 5892, to reflect
those changes and clarify the various relationships involved. It
also makes other minor adjustments to align that document with
Working Group Summary
This is a document regarding recommendations to the registry and
registrar community that could only be developed by experts on IDNA, of
which the IETF has very few. A 4-week IETF-wide Last Call has been more
than enough time for the i18ndir list to remind experts to take a final
look and confirm that there is community consensus, insofar as that ever
exists for these kinds of documents.
The shepherd has done a review of the document and thinks it is
technically sound. The most controversial bit of this document is
actually section 4:
This document restores and clarifies that original language and
intent: absent extremely strong evidence on a per-code point basis
that preserving the validity status of possible existing (or
prohibited) labels would cause significant harm, Unicode changes that
would affect IDNA derived properties are to be reflected in IDNA
exceptions that preserves the status of those labels.
The shepherd is agnostic as to whether this is the correct move, but it
is the only pragmatic choice given the state of the world, and there was
no disagreement with that choice in any of the reviews.
Pete Resnick is the document shepherd, and the responsible AD is Barry Leiba.