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Procedures for IDN TLD Evaluation Deployment in the Root Zone

ICANN has finalized the procedures describing how IANA will manage the insertion, administration and removal of internationalized top- level domains in the root zone for the upcoming evaluation. The procedures were posted previously for public comments. That comment, as well as advice from the technical community (including RSSAC), was taken into consideration in editing the final versions.

The two procedures guiding this effort are:

1. IANA Root Zone Procedures for Test IDN Deployment

The final procedure was approved by the ICANN Board on 29 June 2007 (see after some clarifications were provided in response to public comment (see These procedures are being implemented by IANA in preparation for the insertion of IDN evaluation TLDs.

2. Root Server Operator Procedures for Emergency Revocation of Evaluation-purpose IDN TLDs

The purpose of this procedure is to provide a method of quickly removing IDN TLDs from the root zone in the very unlikely event that insertion of these evaluation strings negatively impact DNS or root server operations. After consultation with the RSSAC, the procedure has been modified to focus on a communication protocol that root server operators will employ in the identification and mitigation of any problems that might arise for root server operations as a consequence of the proposed testing of IDN strings . Root server operators will monitor and identify deteriorated service potentially caused by IDNs in the root. If such a result is detected, ICANN will be notified and in turn activate the procedure.

IDN Program -- looking forward: The next milestones in the IDN Program Plan requires obtaining necessary approvals to insert the eleven suggested evaluation top-level domains (the term <.test> translated into eleven languages). (See the IDN .test Evaluation Plan at http:// An additional announcement will be made once the approvals have been received. It is anticipated that these evaluation TLDs will be launched in late September 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."