Technical Summary
Application protocols using Unicode characters in protocol strings
need to properly prepare such strings in order to perform valid
comparison operations (e.g., for purposes of authentication or
authorization). This document defines a framework enabling
application protocols to perform the preparation and comparison of
internationalized strings ("PRECIS") in a way that depends on the
properties of Unicode characters and thus is agile with respect to
versions of Unicode.
Working Group Summary
The WG spent some time deciding how many classes need to be defined
and what kind of class is suitable for "profiling" for different
purposes. In particular the discussion of use of spaces in Identifier
class took a bit of time. But the WG converged at the end.
This document went through two IETF Last Calls and two IESG
Evaluations. At the end of the first Last Call, concerns were raised
regarding how the term "profiles" was being used in the context of
this document. Additionally, a good deal of the text was copied in
from IDNA instead of importing definitions. The IESG also had
concerns about how the IANA registry was to be created. The document
was updated to address these issues. Additionally, the WG changed the
discussion Directionality to address review comments received during
the second Last Call. Finally, the IAB produced a statement regarding
the issues discovered with the publication of Unicode version 7
(though the issue dates back well before that) that changed
assumptions made during the development of IDNA. Because this
document is based on IDNA, the same issues apply to this document.
The WG addressed this in section 13.4 of the document. The IESG
reviewed this section and, fully understanding that this might
constitute a technical omission in the document, concluded that the
explanation given in this section is sufficient and that the document
was still worth publishing.
Document Quality
The approach used by the document is similar to IDNA 2008 approach
(use of Unicode character properties for deciding what to do with
characters) and thus wasn't controversial (save the discussion noted
above regarding section 13.4).
Several protocols intend to use the framework described in this
document, and people from different working groups have been
contributing to this work, including folks involved in iSCSI and
RADIUS.
Personnel
The document shepherd is Alexey Melnikov.
The responsible Area Director is Pete Resnick.