Domain Name Terms

A glossary of domain terms and definitions

  • Backend Registry Operator (BRO)

  • Blocking

    Definition: See Limited Registration Period. Introduced by ICM Registry during the launch of .XXX, “blocking” means that for a fee a domain name could be blocked from registration as a defensive measure. The domain would not have a full Whois record nor resolve to content aside from a Registry placeholder page.

  • Claims Period (Open Registration)

    Once a Registry Operator opens registration of domain names in its TLDs to all eligible registrants (referred to as “Open Registration” or “General Availability”), the Claims Period begins and will last for 90 days.

    Notifications will occur in the following two instances during this period:

    1. During the registration process at a Registrar, if a potential registrant attempts to register a domain name that is an exact match to a trademark that is in the TMCH, the Registrar must provide the potential registrant a Claims Notice that includes information about the trademark(s) and trademark holder(s) in question as well as require the potential registrant to make an affirmative confirmation to proceed. Please note that if the potential registrant makes the affirmative confirmation, it can continue with the registration (i.e., it will NOT be stopped from completing the registration).

    2. Once a domain name that is an exact match to a trademark that is in the TMCH is successfully registered, a notification e-mail will be sent to the trademark holder(s) that the registration has been made.

  • Country Code Top Level Domain (ccTLD)

    Two letter domains, such as .uk (United Kingdom), .de (Germany) and .jp (Japan), are called Country Code Top Level Domains (ccTLDs) and correspond to a country, territory, or other geographic location.

    For a full listing of the current ccTLDs, see IANA country code Top Level Domains

  • Domain Name System (DNS)

    The Domain Name System (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. It is called its “IP address” (IP stands for “Internet Protocol”). IP Addresses are 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, you can type It is a “mnemonic” device that makes addresses easier to remember.

  • Dispute Resolution Provider (DRP)

    ICANN plans to use independent Dispute Resolution Providers to resolve any disputes between an objector and applicant during the dispute resolution phase of the New gTLD application process. A gTLD application can be objected to on any of the following 4 criteria: 1) string confusion, 2) Existing Legal Rights, 3) Morality and Public Order, and 4) Community Objection. 

  • DNS Security Extensions (DNSSEC)

    DNS security extensions, or DNSSEC, address the problem of DNS cache poisoning by providing a set of DNS extensions which provide origin authentication and integrity checks of DNS data. DNSSEC, however, is only truly effective if a particular TLD zone is DNS protected, and this requires implementation by registries. The Public Interest Registry, the registry for .org, is the first registry to implement DNSSEC.

  • Extensible Provisioning Protocol (EPP)

    The Extensible Provisioning Protocol (EPP) is protocol used by a Registry and Registrar to communicate domain name specific details between one another for the purpose of registering and maintaining domain names. There are two protocols in primary use, RRP (Registry Registrar Protocol) and EPP (Extensible Provisioning Protocol). EPP is in production with most gTLD Registry Operators with the exception of VeriSign. VeriSign has made a contractual commitment to migrate the .com and .net registry system to whichever protocol is adopted as a standard by the IETF community.

  • Founders Programs

    The name of a “program” Registry Operators offer use of certain domain names early on in the launch process of ccTLDs or sTLDs to parties who agree to actively utilize, promote and market the new domain names and by doing so promote the new TLD in question.

  • Generic Names Support Organization (GNSO)

    The Generic Names Support Organization (GNSO) advises the ICANN Board on issues relating to generic top level domains. In August 2007, the GNSO provided 19 “recommendations” and 17 “implementation guidelines” to ICANN for the introduction of new gTLDs into the domain name.  These recommendations and guidelines were approved by the ICANN Board in June 2008.

    The GNSO is the body of 6 constituencies, as follows: the Commercial and Business constituency, the gTLD Registry constituency, the ISP constituency, the non-commercial constituency, the registrar’s constituency, and the IP constituency (which represents brand owners).

  • Generic Top level Domain (gTLD)

    Most TLDs with three or more characters are referred to as “generic” TLDs, or “gTLDs”. They can be subdivided into two types, “unsponsored” TLDs (uTLDs) and “sponsored TLDs (sTLDs).

    Generally speaking, unsponsored TLDs (including .com, .net, .org, .biz, and .info) operate under policies established by the global Internet community directly through the ICANN process, while sponsored TLDs (including .aero, .coop, .edu, .jobs, .mobi, and .museum) are specialized TLDs that have Sponsors representing the narrower community that is most affected by the TLD. The Sponsor carries out delegated policy-formulation responsibilities over many matters concerning the TLD.

    For a full listing of the current gTLDs, see IANA Generic Top Level Domains.

  • Grandfathering

    See Limited Registration Period. “Grandfathering” is the notion of awarding a domain name based on the pre-existence of another domain name. For example, ICM Registry, the registry operator for .XXX and an applicant for .ADULT, .PORN and .SEX TLDs, has stated that it will grandfather registrations in any of the three new strings it is awarded to the holder of the existing .XXX domain name (see

  • Internationalized Domain Name (IDN)

    An Internationalized Domain Name (IDN) is an Internet domain name that contains one or more non-ASCII characters. Such domain names could contain letters with diacritics, as required by many non-English languages, or characters from non-Latin scripts such as Arabic, Hebrew, Chinese or Hindi.

    It is expected that the new gTLD process will include applications for new IDNs.

  • Internet Assigned Numbers Authority (IANA)

    The Internet Assigned Numbers Authority (IANA) organization was originally tasked with responsibility for IP address space assignment, protocol parameter assignment, domain name system management and root server system management prior to ICANN. IANA is now limited to performing the technical delegation of TLDs and address space and managing protocol parameter assignments under ICANN.

  • Internet Corporation for Assigned Names and Numbers (ICANN)

    The Internet Corporation for Assigned Names and Numbers (ICANN) is an internationally organized, non-profit corporation that has responsibility for Internet Protocol (IP) address space allocation, protocol identifier assignment, generic (gTLD) and country code (ccTLD) Top Level Domain name system management, and root server system management functions.

    As a private-public partnership, ICANN is dedicated to preserving the operational stability of the Internet; to promoting competition; to achieving broad representation of global Internet communities; and to developing policy appropriate to its mission through bottom-up, consensus-based processes.

  • Landrush

    See Limited Registration Period. The term “Landrush” originally came out of the first-come, first-served concept of when a Registry opened registration to all eligible parties. However, over the past few years this has generally shifted to an interim period between Sunrise and Open Registration where registrants can make submissions for an increased fee. The Registry Operator will also determine the allocation method for multiple submissions in Landrush.

  • Limited Registration Period

    ICANN has determined that a “Registry Operator may establish additional periods during which it will accept limited domain name registrations following the Sunrise Period but prior to General Registration to domain name registrants who are not Sunrise-Eligible Rights Holders”. “Grandfathering,” “Landrush” and “Blocking” may be part of a Limited Registration Period.

  • Premium Domain Names

    Domain names that are held back during ccTLD and sTLD launches by the Registry Operators in order to be sold at a higher price than “standard” domain names.

  • Registrant

    Registrants are individuals, including individuals representing corporations, who register domain names through registrars. The registrant is required to enter a registration contract with the registrar, which sets forth the terms under which the registration is accepted and will be maintained.

  • Registrar

    Domain names are registered through many different companies known as Registrars. MarkMonitor, for example, is an ICANN-accredited registrar with an exclusive focus on corporate domain portfolios. A complete listing of registrars is in the Accredited Registrar Directory.

    A registrar asks individuals, or “registrants”, various contact and technical information that makes up the registration. The registrar maintains records of the contact information and submits the technical information to a central directory known as the “registry.” The registry provides other computers on the Internet the information necessary to send the registrant email or to find the registrant’s website.

  • Registry

    The 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 which allows computers to route Internet traffic to and from top level domains anywhere in the world. Internet users don’t interact directly with the registry operator; users can register names in TLDs by using an ICANN-Accredited Registrar.

  • Request for Proposal (RFP)

    A Request for Proposal (RFP) is being issued by ICANN to solicit applications for an unlimited limited number of new generic Top Level Domains (gTLDs). The RFP will establish the application process for the new gTLDs. A draft RFP is expected in Q4-08 and the final RFP is expected in Q1-09.

  • Reserved Domain Names

    Per the proposed ICANN Registry agreement, Registry Operators may activate up to 100 domains necessary for the “operation or the promotion of the TLD.”

  • Root

    The root is the list that TLDs exist within. The root exists above the TLDs and defines a given name space by identifying the nameservers that will answer authoritatively for a TLD. ICANN, for example, manages the root on which the great majority of Internet traffic flows. It is possible to have more than one root and in fact some alternate root servers do exist, but have not gained much popularity to date. The root that ICANN manages is centrally managed, but service of the root zone file is provided by a series of geographically and operationally diverse root servers.

  • Root Nameserver

    A root nameserver is a DNS server that answers requests for the DNS root zone, and redirects requests for a particular TLD to that TLD’s nameservers. Although any local implementation of DNS can implement its own private root nameservers, the term “root nameserver” is generally used to describe the thirteen well-known root nameservers that implement the root namespace domain for the Internet’s official global implementation of the Domain Name System.

  • Shared Registration System (SRS)

    The Shared Registration System (SRS) is the software provided by a registry to facilitate the registration of domain names, updates of nameservers, contact information and overall management of a registry. The SRS is used by registrars to connect to the registry.

  • Sponsor

    A Sponsor is an organization to which is delegated some defined ongoing policy-formulation authority regarding the manner in which a particular sponsored TLD is operated. The sponsored TLD has a Charter, which defines the purpose for which the sponsored TLD has been created and will be operated. The Sponsor is responsible for developing policies on the delegated topics so that the TLD is operated for the benefit of a defined group of stakeholders, known as the Sponsored TLD Community, that are most directly interested in the operation of the TLD. The Sponsor also is responsible for selecting the registry operator and to varying degrees for establishing the roles played by registrars and their relationship with the registry operator. The Sponsor must exercise its delegated authority according to fairness standards and in a manner that is representative of the Sponsored TLD Community.

  • Sunrise Period

    An initial phase of a launch. The Sunrise Period is generally based on the existence of a prior right, most often a trademark, as determined by the Registry Operator in question who sets the registration requirements.

    In the New gTLD Program, ICANN has required that each Registry Operator institute a minimum of a 30-day Sunrise Period and provide 30 days public notice before opening that period. The minimum Sunrise registration requirement will be to have a validated trademark in the Trademark Clearinghouse (TMCH), though the Registry Operator may institute additional registration requirements.

    The Registry Operator of a TLD will also determine the allocation method for the Sunrise Period in regard to multiple submissions for the same domain name such as first-come, first served wins; applicants go to auction; or other tiebreakers. Notifications of submissions of exact matches to trademarks in the TMCH will be sent to the respective trademark holders during this period.

  • Thick Registry

    With a thick registry model, all information associated with registered entities, including both technical information (such as information needed to produce zone files) and social information (such as information needed to implement operational, business, or legal practices), is stored within the registry repository.

  • Thin Registry

    With a thin registry model, only the operational data about each domain (such as information to produce zone files) is stored in the central registry database, while contact and billing information is maintained by the registrar sponsoring the domain name. Thus, in this model, the registry only knows the mapping from a domain name to a registrar as well as the associated nameservers. Whois services operated by the registry publish that mapping, while the registrant’s identity is then published by the registrar.

  • Top Level Domain (TLD)

    Top Level Domains (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 (rightmost) “.”, such as “net” in “”. The administrator for a TLD 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.  Generally speaking, two types of TLDs exist: generic TLDs (such as .com, .net, .edu) and country code TLDs (such as .jp, .de, and .cn).

  • Whois

    All domain name registries operate a Whois server for the purpose of providing information about domain names registered with them. In a Shared Registry System, where most information about a domain name is held by registrars, the registry’s Whois server provides a referral to the registrars own Whois server, which provides more complete information about the domain name.

    The Whois service contains registrant, administrative, billing and technical contact information provided by registrars for domain name registrations. 

  • Zone File

    A file on a nameserver that designates a domain name with all of its associated subdomains, IP addresses, and mail server. A zone file is also called a “DNS table.”

  • Additional definitions can be found at: