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Second-level LGR Reference

During the new gTLD program's Pre-Delegation Testing (PDT), ICANN saw an increase in IDN table submissions. The IDN tables submitted by the new gTLD registries varied in the repertoire of characters, variant, contextual rules, and format. On the request of the community, to facilitate and improve consistency of testing and stability of registry operations of new gTLDs, ICANN intends to develop reference IDN tables in machine readable format, called Label Generation Rulesets (LGRs) for the second-level, for use in PDT and the Registry Service Evaluation Process (RSEP). ICANN is implementing a process to ensure both linguistic and technical expert input and community review of these tables being developed and finalized after public comment.

The Guidelines for Developing Reference Label Generation Rulesets (LGRs) for the Second Level has been released. Based on the Guidelines, ICANN will develop the IDN tables and post these for public comment.

Background

A new gTLD registry that wishes to offer IDNs at the second-level to registrants must submit a language or script table for PDT. If a gTLD registry decides to support additional language or script at a later stage, it must undergo the RSEP and submit corresponding IDN table. However, to date, there are no authoritative references available for the community for the purpose of testing IDN tables.

The announcement for Request for Proposals for developing the Reference LGRs for the second-level was released on 5 June 2015.

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""icann.org"" is not an IDN."