An Important Step Toward the Implementation of IDN Top-Level [...]

Revised papers of the technical standards thatdefine the implementation of IDNs - the standards are called IDNA - wererecently released via the IETF editors. These revisions are an important steptoward the delegation of IDN top-level domains.

An informal expert panel, working as what the IETF calls a "design team,"evaluated experiences gained in the implementation of the previous versionof IDNA since its introduction in 2003, and identified several key areas offuture work. These key areas were described in several documents that triggereda formal revision of the IDNA protocol. New versions of the internet-draftsproposing the revisions to the IDNA protocol have been released and are asfollows:

• http://www.ietf.org/internet-drafts/draft-klensin-idnabis-issues-05.txt
• http://www.ietf.org/internet-drafts/draft-klensin-idnabis-protocol-02.txt
• http://www.ietf.org/internet-drafts/draft-alvestrand-idna-bidi-01.txt
• http://www.ietf.org/internet-drafts/draft-faltstrom-idnabis-tables-03.txt

The core components in the revision effort include:

• definition of valid IDN labels, an inclusion-based model that clearlydefines which characters will be available for IDNs (the current model isexclusion-based), and recognizes the implications of the Unicode handlingof various scripts on use in IDNs;
• elimination of confusing and non-reversible character mappings;
• fixing an error in right-to-left error in Stringprep (a profile usedto prepare IDNs in the IDNA protocol ), and eliminating Unicode versiondependencies, thereby permitting more scripts to be used in IDNs nowand in the future.

The issues with the current IDN model that led to these revisions are discussedin RFC4690. This RFC discusses specific character issues where the same scriptis used in different languages, issues related to cases where languages canbe expressed by using more than one script, issues involving bi-directionalcases, and issues concerning the topic of visually confusing characters.

ICANN urges the Internet technical community to take part in the final stagesof this development work by reviewing this documentations and constructivelycommenting on it. The review is moving forward in accordance with standardIETF processes. The intention is to finalize this work and publish the newIDNA standard within the next two months.