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Registry Information

Please note that the English language version of all translated content and documents are the official versions and that translations in other languages are for informational purposes only.

Registry Information

ICANN's gTLD Registry area encompasses information about both sponsored and unsponsored generic top-level domains. The relationships between ICANN and the gTLD registries are governed by the individual Registry or Sponsorship Agreements, which set out the obligations of both parties.

Basic TLD Information

The right-most label in a domain name is referred to as its "top-level domain" (TLD). TLDs with two letters have been established for over 250 countries and external territories and are referred to as "country-code" TLDs or "ccTLDs". TLDs with three or more characters are referred to as "generic" TLDs, or "gTLDs".

The responsibility for operating each TLD (including maintaining a registry of the domain names within the TLD) is delegated to a particular organization. These organizations are referred to as "registry operators" or "sponsors". Currently, domain names under the following gTLDs are available, and the corresponding registries are under contract with ICANN: .aero, .asia, .biz, .cat, .com, .coop, .info, .jobs, .mobi, .museum, .name, .net, .org, .pro, .tel and .travel.

Generally speaking, an unsponsored gTLD Registry operates under policies established by the global Internet community directly through the ICANN process. .biz, .com, .info, .name, .net, .org, and .pro are unsponsored TLDs.

A sponsored TLD is a specialized TLD that has a sponsor representing a specific community that is served by the TLD. The sponsor thus carries out delegated policy-formulation responsibilities over many matters concerning the TLD. .aero, .asia, .cat, .coop, .jobs, .mobi, .museum, .tel and .travel are sponsored TLDs.

What We Do

As the business environment changes, and technology continues to develop, ICANN staff works closely with the gTLD registries to review and adapt the provisions of the Registry and Sponsorship Agreements.

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."