Preparation and Comparison of Internationalized Strings

Document Charter Preparation and Comparison of Internationalized Strings WG (precis)
Title Preparation and Comparison of Internationalized Strings
Last updated 2010-06-11
State Approved
WG State Concluded
IESG Responsible AD Alexey Melnikov
Charter Edit AD (None)
Send notices to (None)


Problem Statement
  The use of non-ASCII strings in Internet protocols requires additional
  processing to be handled properly. As part of the Internationalized
  Domain Names (idn) work in 2003, a method for preparation and comparison
  of internationalized strings was defined and generalized to be re-used
  by other protocols. This "stringprep" method [RFC 3454]
defines the   overall framework whereas specific protocols define their
own profiles.   Known existing IETF profiles are:     - The
Nameprep profile [RFC 3490] for use in Internationalized Domain   Names in
Applications (IDNA)   - The iSCSI profile [RFC 3722] for use in Internet
Small Computer   Systems Interface (iSCSI) Names   - The Nodeprep and
Resourceprep profiles [RFC 3920] for use in the   Extensible Messaging and
Presence Protocol (XMPP)   - The Policy MIB profile [RFC 4011] for use in
the Simple Network   Management Protocol (SNMP)   - The SASLprep
profile [RFC 4013] for use in the Simple Authentication   and Security
Layer (SASL)   - The trace profile [RFC 4505] for use with the SASL
ANONYMOUS mechanism   - The LDAP profile (RFC 4518] for use with LDAP
    The IAB completed a review of IDN and made recommendations for
change   [RFC 4690], which triggered a new version of the IDNA protocol
called   IDNA2008. Whereas IDNA2003 was tied to Unicode 3.2 via
stringprep,   IDNA2008 does not use the stringprep method, but instead
uses an   algorithm based on the properties of Unicode characters, which
makes it   agile to the Unicode database version. The protocols using
stringprep   need Unicode version agility and therefore need to
investigate whether   and how to move away from the current stringprep
approach, with the   associated challenges of backward compatibility and
migration.     Objectives     The goal of this group is to
assess whether a new method based on the   new IDNA2008 algorithmic
approach is the appropriate path forward for   existing stringprep
protocols as well as for other application protocols   requiring
internationalized strings.     The group will evaluate if a new
generalized framework based on the   algorithmic approach is appropriate
and, if so, define it.     The group will analyze existing stringprep
profiles and will do one of   the following with regard to each profile:
    1. Develop a replacement for the profile in close collaboration
with the   related protocol working group (if any).     2.
Collaborate with another active working group which will be   developing
the new profile as part of its charter.     3. Advise the authors of
profiles for which there is no active working   group how to proceed.
    The group will also define a set of best current practices for
  preparation and comparison of internationalized strings.    
Because the framework, profile replacements, and guidelines are very  
much interrelated, work on them will proceed in parallel as much as  
possible.     Based on normal working group processes for achieving
consensus, the   group will attempt to gather input from, and may provide
advice to,   "customers" working on IETF technologies other than
those listed above,   including but not limited to Network Address
Identifiers (RFC 4282) and   Kerberos (RFC 4120). However, the group will
prioritize work on the   listed stringprep profiles higher than work on
other technologies, and   will formally accept additional tasks as
official milestones only after   rechartering.     In completing
its tasks, the working group should collaborate with other   teams
involved in internationalized identifiers, such as the IETF's IRI  
and EAI working groups as well as other relevant standards development  
organizations (e.g., the Unicode Consortium).     Deliverables  
  1. Problem statement / analysis of existing stringprep profiles  
(Informational).     2. Possible new framework to replace stringprep
(Standards Track).     3. Possible replacements for the existing IETF
stringprep profiles as   listed earlier in this charter (Standards Track).
    4. String preparation and comparison guidelines (BCP).