Formal submission of our documents to AD
Vint Cerf
vint at google.com
Sat Sep 26 14:45:55 CEST 2009
We have formally submitted our documents to the Area Director, Lisa
Dusseault, for consideration by the IESG.
IDNABIS - Internationalized Domain Names for Applications
Document Shepherd Write-up for the IESG
1a. The document shepherd for the ensemble of six IDNABIS documents is
Vinton Cerf, also serving as the WG chair. I have personally reviewed
each document and consulted with the WG and the document editors and
believe these documents are now ready for AD and IESG consideration
for release as RFCs. The documents are:
(i) Definitions: draft-ietf-idnabis-defs-11.txt
(ii) Protocol: draft-ietf-idnabis-protocol-16.txt
(iii) Bi-Di: draft-ietf-idnabis-bidi-06a.txt
(iv) Tables: draft-ietf-idnabis-tables-07.txt
(v) Rationale: draft-ietf-idnabis-rationale-13.txt
(vi) Mappings: draft-ietf-idnabis-mappings-04.txt
Of these, Definitions, Protocol, Bi-Di and Tables are normative;
Rationale and mappings are non-normative documents but part of the
proposed standard ensemble.
1b. The initial impetus for the revisiting of the IDNA2003 proposed
standards emerged in written form in RFC4690. An informal technical
team worked to develop a framework for consideration which was later
discussed, edited, and ratified to create the IDNABIS working group in
2008. The documents resulting from the IDNABIS Working Group effort
have been extensively discussed over a two year period by the WG and
by interested parties especially language experts in the Chinese,
Japanese and Hangul spaces, speakers of Hebrew, Indic languages as
well as a working group of expert Arabic speakers. The WG has had the
participation of several Unicode consortium representatives including
the chairman of the UTC. It should not surprise the IESG that there
was controversy during the development of these documents and at best
a rough consensus has formed around the recommendations. There
continue to be some parties who resist the results. I think the two
years of work have been more than sufficient - arguments have been
revisited multiple times with the same outcomes.
1c. I do not believe that it is necessary to seek additional review by
specialist parties. The working group had a great deal of
representation from many perspectives and many volunteered their
comments (some coming in at the last moment during WG last call - not
surprisingly). The last call was effectively extended to last a month
owing to discussions and substantive contributions arriving during
this period and rough consensus has been reached on the documents as
they are now composed.
1d. There was an impasse relating to mapping of Unicode characters
into other Unicode characters prior to the generation of a punycode
equivalent string to produce an A-label [please see the Definitions
document]. This was resolved by introducing a non-normative "mappings"
document observing ways in which this aspect of dealing with
internationalized domain names might be approached. The principal
rationale for re-visiting the IDNA2003 recommendations arose from
field experience and a recommendation from the IAB [RFC4690]. A major
objective was to re-specify the standard in such a way as to make it
independent of changes to the Unicode code set (something that evolves
more or less continuously). The method for achieving this is to use
the Unicode properties feature (per code-point/character) to determine
whether the code point should be allowed, disallowed or used only
under certain conditions in domain name labels. There remains the
problem of deployment in a world of web servers, browsers and other
applications using domain names that may have already implemented the
IDNA2003 recommendations. The IESG may encounter implementation
tactics for dealing with the old and new specifications that are
controversial. Perfect backward compatibility with IDNA2003 was not
possible (without simply replicating it, negating the rationale for
the redefinition effort of IDNA2008). IESG members will note that this
is 2009 but the new specifications bear the label IDNA2008 because the
work was started in that year. This is particularly true of the
special characters "esszet" or "sharp-S" used in German and the "final
sigma" used in Greek. These were mapped into other valid Unicode
characters under IDNA2003 but allowed in IDNA2008 because the Unicode
code points for these were introduced in the interim between IDNA2003
and IDNA2008 standardization efforts. The treatment of languages that
are expressed in Right-to-Left form (see "Bi-Di" document) has been
revised relative to IDNA2003 and it is believed that the revision is
clearer and more precise in its form and limitations on the use of
numeric characters, for example.
An IPR disclosure statement has not been filed. I am not aware of any
claims to IPR associated with any of the documents and proposed
standards.
1e. The consensus behind these documents is based in part on the
observation that repeated revisiting of issues produced the same
results. There are still parties who are not in complete agreement
with the results but after the introduction of the mapping document
and considerable debate about its nature, much of the controversy was
resolved, leading the chairman to declare that a reasonable basis for
consensus existed. There remain a small number of parties who resist
the outcomes but the bulk of the working group appears to be in
agreement with or supportive of the results. Application of the
proposed standards will face the problem of existing IDNA2003-
conformant implementations. There is reported to be an apparent desire
among browser implementers to avoid double DNS lookups under each
framework. The simple fact of non-uniform propagation of IDNA2008-
conformant implementations in all software that needs to be aware of
and processs Internationalized Domain Names adds to the likelihood of
various DNS-using implementations that are i) IDNA-unaware, ii)
IDNA2003-aware only or IDNA2008 and IDNA2003 aware.
1f. There has been no overt threat of appeal. See (1d) however
regarding implementation tactics and vendor response to the new
IDNA2008 specifications.
1g. As far as I can determine, these documents meet all I-D criteria.
1h. The document ensemble is split into normative and informational
parts, as outlined in (1a). All documents are ready for advancement as
Proposed Standards. No previous RFCs are affected except for those
associated with IDNA2003 [RFC3490]. In particular, there is no change
to the use of Punycode [RFC3492] and neither Nameprep [RFC3491] nor
Stringprep [RFC3454] are used in IDNA2008.
1i. IANA sections exist as required. As per IDNA2003, IANA will need
to generate tables reflecting the application of the IDNA2008 Tables
rules to the current Unicode release. In particular, reference is
drawn to Sections 5.1 and 5.2 of the Tables document, reproduced below
for convenience:
5.1. IDNA derived property value registry
IANA is to keep a list of the derived property for the versions of
Unicode that is released after (and including) version 5.1. The
derived property value is to be calculated according to the
specifications in sections Section 2 and Section 3 and not by copying
the non-normative table found in Appendix B. Changes to the rules,
including BackwardCompatible (Section 2.7) (a set that is at release
of this document is empty), require IETF Review, as described in
[RFC5226]
5.2. IDNA Context Registry
For characters that are defined in the IDNA Character Registry list as
CONTEXTO or CONTEXTJ and therefore requiring a contextual rule IANA
will create and maintain a list of approved contextual rules.
Additions or changes to these rules require IETF Review, as described
in [RFC5226]. A table from which that registry can be initialized,
and some further discussion, appears in Appendix A.
1j. The Tables document does not require automatic evaluation of
formulas
1k. Document Announcement draft
Technical Summary
The Internationalized Domain Names for Applications (IDNA) revisions
are intended to reduce significantly IDNA dependency on specific
versions of the Unicode character coding system. The Working Group
produced the following documents representing a revision to the
earlier "IDNA2003" proposed standard [only RFC 3490 is specifically
affected]:
[Note to RFC Editor: these references should be replaced with their
RFC counterparts when the documents are approved for release by the
IESG]
Definitions: draft-ietf-idnabis-defs-11.txt
Protocol: draft-ietf-idnabis-protocol-16.txt
Bi-Di: draft-ietf-idnabis-bidi-06a.txt
Tables: draft-ietf-idnabis-tables-07.txt
Rationale: draft-ietf-idnabis-rationale-13.txt
Mappings: draft-ietf-idnabis-mappings-04.txt
Of these, Definitions, Protocol, Bi-Di and Tables are normative;
Rationale and mappings are non-normative documents but part of the
proposed standard ensemble.
Working Group Summary
The initial impetus for the revisiting of the IDNA2003 proposed
standards emerged in written form in RFC4690. An informal technical
team worked to develop a framework for consideration that was later
discussed, edited, and ratified to create the IDNABIS working group in
2008. The documents resulting from the IDNABIS Working Group effort
have been extensively discussed over a two year period by the WG and
by interested parties especially language experts in the Chinese,
Japanese and Hangul spaces, speakers of Hebrew, Indic languages as
well as a working group of expert Arabic speakers. The WG has had the
participation of several Unicode consortium representatives. There was
controversy during the development of these documents but a rough
consensus has formed around the recommendations.
There was an impasse relating to mapping of Unicode characters into
other Unicode characters prior to the generation of a punycode
equivalent string to produce an A-label [please see the Definitions
document]. This was resolved by introducing a non-normative "mappings"
document observing ways in which this aspect of dealing with
internationalized domain names might be approached. The principal
rationale for re-visiting the IDNA2003 recommendations arose from
field experience and a recommendation from the IAB [RFC4690]. A major
objective was to re-specify the standard in such a way as to make it
independent of changes to the Unicode code set (something that evolves
more or less continuously). The method for achieving this is to use
the Unicode properties feature (per code-point/character) to determine
whether the code point should be allowed, disallowed or used only
under certain conditions in domain name labels. There remains the
problem of deployment in a world of web servers, browsers and other
applications using domain names that may have already implemented the
IDNA2003 recommendations. The IESG may encounter implementation
tactics for dealing with the old and new specifications that are
controversial. Perfect backward compatibility with IDNA2003 was not
possible (without simply replicating it, negating the rationale for
the redefinition effort of IDNA2008). IESG members will note that this
is 2009 but the new specifications bear the label IDNA2008 because the
work was started in that year. This is particularly true of the
special characters "esszet" or "sharp-S" used in German and the "final
sigma" used in Greek. These were mapped into other valid Unicode
characters under IDNA2003 but allowed in IDNA2008 because the Unicode
code points for these were introduced in the interim between IDNA2003
and IDNA2008 standardization efforts. The treatment of languages that
are expressed in Right-to-Left form (see "Bi-Di" document) has been
revised relative to IDNA2003 and it is believed that the revision is
clearer and more precise in its form and limitations on the use of
numeric characters, for example.
Document Quality
There are test implementations of the rules proposed by IDNA2008 but
no released operational software. Such implementations have awaited
the achievement of rough consensus on the controversial parts of the
new proposals. Inputs from special expert bodies such as a Korean
expert language group, an informal Arabic speakers group, and a number
of individual commentators from the Unicode community, among others,
have contributed to the documents as they now exist. Multiple
implementations of the Tables rules have confirmed the stability of
the definitions under distinct implementation.
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