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ICANN Moves Forward Towards Introduction Of Internationalized Top Level Labels (IDNs) in the DNS

Today, ICANN posted a set of draft procedures describing how IANA will manage the insertion, administration and removal of internationalized top-level labels (as delegated A-records) in the DNS root zone. These procedures are intended to guide an evaluation plan providing for the insertion and monitoring of sample IDNs into the root zone later this year.

This announcement includes the draft procedure itself (IANA Root Zone Procedures for Test IDN Deployment, and a draft paper (IDN TLD Root Server Performance / Tolerance) describing the negative impacts to the DNS (tolerance measure) that, if observed, would trigger an emergency revocation procedure. The revocation procedure provides for the rapid removal of IDNs from the root zone if these negative impacts rise to the level specified in the tolerance document. The Root Server System Advisory Committee (RSSAC) is also analyzing the tolerance measure .

The public comment period is open until June 22, 2007 at 00:00 UTC. Following the public comment period ICANN staff will revise these documents and publish a final set of procedures that will be reviewed by ICANN Board of Directors at the ICANN Meeting in San Juan (25-29 June 2007).  The procedure will be implemented according to standard processes for newly adopted or revisions to IANA services.

Public comments can be submitted to and reviewed at

Looking forward:

These papers are a corner piece in ICANN’s IDN Program that currently is developing an evaluation plan for insertion of a set of temporary internationalized top-level labels in the DNS. The evaluation plan will take into consideration all received advise and requests from the past several IDN workshops at ICANN meetings and other events. The evaluation plan will be posted for community review before it is finalized and implemented.  The evaluation plan will be posted prior to the ICANN meeting in San Juan that takes place on 25-29 June 2007.

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Domain Name System
Internationalized Domain Name ,IDN,"IDNs are domain names that include characters used in the local representation of languages that are not written with the twenty-six letters of the basic Latin alphabet ""a-z"". An IDN can contain Latin letters with diacritical marks, as required by many European languages, or may consist of characters from non-Latin scripts such as Arabic or Chinese. Many languages also use other types of digits than the European ""0-9"". The basic Latin alphabet together with the European-Arabic digits are, for the purpose of domain names, termed ""ASCII characters"" (ASCII = American Standard Code for Information Interchange). These are also included in the broader range of ""Unicode characters"" that provides the basis for IDNs. The ""hostname rule"" requires that all domain names of the type under consideration here are stored in the DNS using only the ASCII characters listed above, with the one further addition of the hyphen ""-"". The Unicode form of an IDN therefore requires special encoding before it is entered into the DNS. The following terminology is used when distinguishing between these forms: A domain name consists of a series of ""labels"" (separated by ""dots""). The ASCII form of an IDN label is termed an ""A-label"". All operations defined in the DNS protocol use A-labels exclusively. The Unicode form, which a user expects to be displayed, is termed a ""U-label"". The difference may be illustrated with the Hindi word for ""test"" — परीका — appearing here as a U-label would (in the Devanagari script). A special form of ""ASCII compatible encoding"" (abbreviated ACE) is applied to this to produce the corresponding A-label: xn--11b5bs1di. A domain name that only includes ASCII letters, digits, and hyphens is termed an ""LDH label"". Although the definitions of A-labels and LDH-labels overlap, a name consisting exclusively of LDH labels, such as"""" is not an IDN."