Skip to main content


ICANN Holds First Capacity Development Workshop for Asia GAC Members

SINGAPORE – 15 February 2018 – The Internet Corporation for Assigned Names and Numbers (ICANN), in cooperation with the ICANN Governmental Advisory Committee (GAC) Underserved Regions Working Group, announced today the first capacity-development...

Draft Procedure for Community gTLD Change Requests

Open Date: 14 February 2018 Close Date: 2 April 2018 Originating Organization: Global Domains Division Categories/Tags: Contracted Party Agreements Brief Overview: The ICANN organization is...

View the Latest Quarterly Stakeholder Update and Register for the Q&A Call on 22 February

LOS ANGELES – 14 February 2018 – Today, the Internet Corporation for Assigned Names and Numbers (ICANN) published its FY18 Q2 Stakeholder Update for the quarter ending 31 December 2017. Göran Marby, President and CEO, and Cherine Chalaby, Chairman...

Register Now: Pre-ICANN61 Policy Open House – 1 March 2018

The Policy Development Support Team is pleased to announce two sessions for an upcoming webinar: Pre-ICANN61 Policy Open House Thursday, 1 March 2018 10:00 and 19:00 Coordinated Universal Time (UTC) The webinar will run in English and will...




ICANN's Multistakeholder Policy Development Process | English

Learn how the ICANN Policy Development Support Team facilitates bottom-up, consensus-driven processes for global generic top-level domains (gTLD), country code top-level domains (ccTLD), and...


Quarterly Stakeholder Update FY18 Q2

Quarterly Stakeholder Update FY18 Q2

Artworks 000250073323 aloqht t500x500

Steve Crocker Tribute Video

A tribute to Steve Crocker, former ICANN Board Chair, during ICANN60 in Abu Dhabi.

Artworks 000250072930 3s4341 t500x500

Interview With Jonathan Zuck and Drew Bagley

Learn about the progress and next steps of the Competition, Consumer Trust, and Consumer Choice Review from CCT Chair Jonathan Zuck and CCT Independent Expert Drew Bagley. In this interview,...


Blog Posts

Hero1 gdpr data protection privacy update 750x425 14feb18 en

Data Protection/Privacy Update: Latest Developments

Supporting Standards that Ensure an Open and Interoperable Internet


Sign Up to Get News Updates

Tell us which topics you care about and we'll send updates to your homepage and email.

Already have an Account? Sign In

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."