TLD Glossary



The ASCII-Compatible Encoding (ACE) form of an IDNAvalid string.

An entity that has applied to ICANN for a new gTLD by submitting its application form through the online application system.

An application for a new gTLD lodged in response to this RFP. An application includes the completed Application Form, any supporting documents, and any other information that may be submitted by the applicant at ICANN’s request.

Application form
The set of questions to which applicants provide responses, included as an attachment to Module 2 of the Applicant Guidebook.

Application interface
The web-based interface operated by ICANN.

Application round
The complete succession of stages for processing the applications received during one application submission period for gTLDs. This RFP is for one application round. Any subsequent application rounds will be the subject of subsequent RFPs.

Application submission period
The period during which applicants may submit applications through the application interface. Applied for gTLD string A gTLD string that is subject of an application.

American Standard Code for Information Interchange (ASCII)
A character encoding based on the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that work with text. Most modern character encodings—which support many more characters than did the original—have a historical basis in ASCII.

A method for allocating property or goods to the highest bidder.

Auction round
Within an auction, the period of time commencing with the announcement of a start-of-round price and concluding with the announcement of an end-of-round price.

Asynchronous full transfer, a DNS protocol mechanism through which a DNS zone can be replicated to a remote DNS server.


An applicant who participates in an auction.

Business ID
A number such as a federal tax ID number or employer information number.


Two-letter top-level domains corresponding with the ISO 3166-1 country code list. See

Community-based TLD
A community-based gTLD is a gTLD that is operated for the benefit of a defined community consisting of a restricted population. An applicant designating its application as community-based must be prepared to substantiate its status as representative of the community it names in the application.

Community objection
An objection based on the grounds that there is substantial opposition to a gTLD application from a significant portion of the community to which the gTLD string may be explicitly or implicitly targeted.

Comparative evaluation
A process to resolve string contention, which may be elected by a community-based applicant.

Consensus policy
A policy created through the GNSO policy development process listed in Annex A of the ICANN Bylaws. See A list of current consensus policies is available at

Contention sets
A group of applications containing identical or similar applied-for gTLD strings.

Country-code TLD
See ccTLD.


The process through which the root zone is edited to include a new TLD, and the management of domain name registrations under such TLD is turned over to the registry operator.

Any digit between “0” and “9” (Unicode code points U+0030 to U+0039).

Dispute Resolution Service Provider (DRSP)
An entity engaged by ICANN to adjudicate dispute resolution proceedings in response to formally filed objections.

Domain name
A name consisting of two or more (for example, levels, maintained in a registry database.

Domain Name System (DNS)
The Internet Domain Name System. The DNS helps users find their way around the Internet. Every computer on the Internet has a unique address—just like a telephone number—which is a rather complicated string of numbers. Called an IP address (IP stand for Internet Protocol), the string of numbers is hard to remember. The DNS makes using the Internet easier by allowing a familiar string of letters (the domain name) to be used instead of the arcane IP address. So instead of typing, a user can type It is a mnemonic device that makes addresses easier to remember.

Domain Name System Security Extensions (DNSSEC)
DNSSEC secures domain name lookups on the Internet by incorporating a chain of digital signatures into the DNS hierarchy.


Existing TLD
A string included on the list at

Extended Evaluation
The second stage of evaluation applicable for applications that do not pass the Initial Evaluation, but are eligible for further review.

Extended Evaluation period
The period that may follow the Initial Evaluation period, for eligible applications which do not pass the Initial Evaluation.

The individuals or organization(s) appointed by ICANN to perform review tasks within Initial Evaluation and Extended Evaluation under ICANN direction.

Evaluation fee
The fee due from each applicant to obtain consideration of its application.


Geographic Names Panel (GNP)
A panel of experts charged by ICANN with reviewing applied-for TLD strings that relate to geographical names.

Generic Names Supporting Organization (GNSO)
ICANN’s policy-development body for generic TLDs and the lead in developing the policy recommendations for the introduction of new gTLDs.

Generic top-level domain
See gTLD.

A TLD with three or more characters that does not correspond to any country code.



The hyphen “-” (Unicode code point U+0029).


Internet Assigned Numbers Authority (IANA)
IANA is the authority originally responsible for overseeing IP address allocation, coordinating the assignment of protocol parameters provided for in Internet technical standards, and managing the DNS, including delegating top-level domains and overseeing the root name server system. Under ICANN, IANA distributes addresses to the Regional Internet Registries, coordinate with the IETF and other technical bodies to assign protocol parameters, and oversees DNS operation.

Internet Corporation for Assigned Names and Numbers.

ICANN-accredited registrar
A company that registers domain names for Internet users. There are more than 900 ICANN-accredited registrars who provide domains to Internet users. The list of ICANN-accredited registrars is available at

Internationalized Domain Name (IDN)
A domain name including at least one character other than those in letters (a,…,z), digits (0,…,9) and the hyphen (-).

Internationalizing Domain Names in Applications (IDNA)
The technical protocol used for processing domain names containing non-ASCII characters in the DNS.

IDN ccTLD Fast Track
The process for introducing a limited number of IDN ccTLDs associated with the ISO-3166 two-letter codes. See

IDN table
A table listing all those characters that a particular TLD registry supports. If one or more of these characters are considered a variant this is indicated next to that/those characters. It is also indicated which character a particular character is a variant to. The IDN tables usually hold characters representing a specific language, or they can be characters from a specific script. Therefore the IDN table is sometimes referred to as “language variant table”, “language table”, “script table” or something similar.

Inter-governmental organization.

Internet Engineering Task Force (IETF)
The IETF is a large, open international community of network designers, operators, vendors, and researchers concerned with the evolution of the Internet architecture and the smooth operation of the Internet.

Initial Evaluation period

The period during which ICANN will review an applied-for gTLD string, an applicant’s technical and financial capabilities, and an applicant’s proposed registry services.

International Phonetic Alphabet
A notational standard for phonetic representation in multiple languages. See

Incremental Zone Transfer, a DNS protocol mechanism through which a partial copy of a DNS zone can be replicated to a remote DNS server.

LDH (Letter Digit Hyphen)
The hostname convention defined in RFC 952, as modified by RFC 1123.


Legal rights objection
An objection on the grounds that the applied-for gTLD string infringes existing legal rights of the objector.

Any character between “a” and “z” (in either case) (Unicode code points U+0061 to U+007A or U+0041 to U+005A).

Limited liability corporation.


Morality and public order objection
An objection made on the grounds that the applied-for gTLD string is contrary to generally accepted legal norms of morality and public order that are recognized under international principles of law.


A formal objection filed with a Dispute Resolution Service Provider in accordance with that provider’s procedures.

Objection filing period
The period during which formal objections may be filed concerning a gTLD application submitted to ICANN.

One or more persons or entities that have filed a formal objection against a new gTLD application with the appropriate DRSP.

Open TLD
An open TLD can be used for any purpose consistent with the requirements of the application and evaluation criteria, and with the registry agreement. An open TLD may or may not have a formal relationship with an exclusive registrant or user population. It may or may not employ eligibility or use restrictions.


Pre-delegation test
A technical test and other steps required of applicants before delegation of the applied-for gTLD string into the root zone.

Primary contact
The person named by the applicant as the main contact for the application, and having authority to execute decisions concerning the application.

Principal place of business
The location of the head office of a business or organization.


See ICANN-accredited registrar.

A registry is the authoritative, master database of all domain names registered in each top-level domain. The registry operator keeps the master database and also generates the zone file that allows computers to route Internet traffic to and from top-level domains anywhere in the world.

Registry Agreement
The agreement executed between ICANN and successful gTLD applicants, which appears in draft form at

Registry operator
The entity entering into the Registry Agreement with ICANN, responsible for setting up and maintaining the operation of the registry.

Registry services
(1) Operations of the registry critical to the following tasks:
(i) the receipt of data from registrars concerning registrations of domain names and name servers; (ii) provision to registrars of status information relating to the zone servers for the TLD; (iii) dissemination of TLD zone files; (iv) operation of the registry zone servers; and (v) dissemination of contact and other information concerning domain name server registrations in the TLD as required by the registry agreement; and (2) other products or services that the registry operator is required to provide because of the establishment of a consensus policy; and (3) any other products or services that only a registry operator is capable of providing, by reason of its designation as the registry operator.

Registry Services Technical Evaluation Panel (RSTEP)
The Registry Services Technical Evaluation Panel is a group of experts in the design, management, and implementation of the complex systems and standards protocols used in the Internet infrastructure and DNS. RSTEP members are selected by its chair. All RSTEP members and the chair have executed an agreement requiring that they consider the issues before the panel neutrally and according to the definitions of security and stability.

Reserved Name
A string included on the Top-Level Reserved Names List (Refer to paragraph of Module 2).

Request for Comments (RFC)
The RFC document series is the official publication channel for Internet standards documents and other publications of the IESG, IAB, and Internet community.

The person or entity that maintains a set of rights to a certain piece of property.

Root Zone
The root zone database represents the delegation details of top-level domains, including gTLDs and country-code TLDs. As manager of the DNS root zone, IANA is responsible for coordinating these delegations in accordance with its policies and procedures.

See application round.


A collection of symbols used for writing a language. There are three basic kinds of script. One is the alphabetic (e.g. Arabic, Cyrillic, Latin), with individual elements termed “letters”. A second is ideographic (e.g. Chinese), the elements of which are “ideographs”. The third is termed a syllabary (e.g. Hangul), with its individual elements represent syllables. The writing systems of most languages use only one script but there are exceptions such as for example, Japanese, which uses four different scripts, representing all three of the categories listed here. It is important to note that scripts which do not appear in the Unicode Code Chart are completely unavailable for inclusion in IDNs.

In relation to a proposed registry service, an effect on security by the proposed Registry Service means (1) unauthorized disclosure, alteration, insertion, or destruction of registry data, or (2) unauthorized access to or disclosure of information or resources on the Internet by systems operating in accordance with all applicable standards.

Shared Registry System (SRS)
A system that allows multiple registrars to make changes to a registry simultaneously.

In relation to a proposed registry service, an effect on stability means that the proposed registry service (1) does not comply with applicable relevant standards that are authoritative and published by a well-established, recognized, and authoritative standards body, such as relevant standards-track or best current practice RFCs sponsored by the IETF; or (2) creates a condition that adversely affects the throughput, response time, consistency, or coherence of responses to Internet servers or end systems, operating in accordance with applicable relevant standards that are authoritative and published by a well-established, recognized and authoritative standards body, such as relevant standards-track or best current practice RFCs and relying on registry operator’s delegation information or provisioning services.

The string of characters comprising an applied-for gTLD.

String confusion objection
An objection filed on the grounds that the applied-for gTLD string is confusingly similar to an existing TLD or to another applied-for gTLD.

String similarity Algorithm
An algorithmic tool used to identify applied-for gTLD strings that may result in string confusion.

String similarity Examiners
A panel charged with identifying applied-for gTLD strings that may result in string confusion.

String contention
The scenario in which there is more than one qualified applicant for the same gTLD or for gTLDs that are so similar that detrimental user confusion would be the probable result if more than one were to be delegated to the root zone.


TLD Application System (TAS)
The online interface for submission of applications to ICANN.

Top-Level Domain (TLD)
TLDs are the names at the top of the DNS naming hierarchy. They appear in domain names as the string of letters following the last (right-most) dot, such as “net” in The TLD administrator controls what second-level names are recognized in that TLD. The administrators of the root domain or root zone control what TLDs are recognized by the DNS.


A “U-label” is an IDNA-valid string of Unicode characters, including at least one non-ASCII character, expressed in a standard Unicode Encoding Form, normally UTF-8 in an Internet transmission context.

Unicode is a commonly used single encoding scheme that provides a unique number for each character across a wide variety of languages and scripts. The Unicode standard contains tables that list the “code points” (unique numbers) for each local character identified. These tables continue to expand as more and more characters are digitalized. In Unicode, characters are assigned codes that uniquely define every character in many of the scripts in the world. These “code points” are unique numbers for a character or some character aspect such as an accent mark or ligature. Unicode supports more than a million code points, which are written with a “U” followed by a plus sign and the unique number in hexadecimal notation; for example, the word “Hello” is written U+0048 U+0065 U+006C U+006C U+006F.

Uniform Domain Name Dispute Resolution Policy (UDRP)
A policy for resolving disputes arising from alleged abusive registrations of domain names (for example, cybersquatting), allowing expedited administrative proceedings that a trademark rights holder initiates by filing a complaint with an approved dispute resolution service provider.

User registration fee
The fee paid by prospective applicants for new TLDs to obtain access to the TLD Application System (TAS).


Records containing registration information about registered domain names.