ICANN Acronyms and Terms

ICANN has hundreds of acronyms and terms, which can be confusing. We created this multilingual tool to help explain what these terms mean and facilitate your work within the ICANN community.

ICANN Acronyms and Terms

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1-20 of 32 results

cache poisoning attack

An attack that inserts fraudulent data into the cache of a Domain Name System (DNS) resolver. A cache is a local storage area where name resolvers store results of the DNS lookups that they process. To speed lookups, a resolver searches for answers in its cache before forwarding queries to authoritative name servers or upstream resolvers.

In a cache poisoning attack, a cyberattacker substitutes fraudulent DNS data for a popular domain name in a name server’s cache. Once the cache has been poisoned, subsequent queries for that domain name direct the attacker’s victims to a malware-hosting or phishing website.

caching resolver

A Domain Name System (DNS) server that queries authoritative name servers to obtain Internet Protocol (IP) addresses for DNS clients, and then saves the query results in local storage (cache). By storing query results in cache, a resolver can quickly retrieve IP addresses for domain names that it has already resolved.

Centralized Zone Data Service(CZDS)

A central online access point where interested parties can request access to the zone files provided by participating generic top-level domains (gTLDs). A zone file contains information about the domain names that are active in a particular gTLD. All new gTLD registry operators are required to provide zone data as described in their Registry Agreement with ICANN.

chain of trust

A collection of information to ensure the delegation of responsibility from one party to another can be verified using electronic certificates. To verify using a chain of trust, each link in the chain from a known trust anchor to the resource in question must be signed by the link’s parent.


The basic graphic unit of a writing system, which is a script plus a set of rules determining how it is used for representing a specific language. In phonetic writing systems, a character is typically a letter or represents a syllable. In ideographic, pictographic, or logographic systems, a character may represent a concept or word.

Claims Service

A rights protection service available to trademark holders who verify their marks with the Trademark Clearinghouse (TMCH). The Claims Service notifies individuals who attempt to register a domain name that it matches a trademark in the TMCH. If the registrant elects to proceed with the registration, the Claims Service notifies the holders whose TMCH-registered marks match the registrant’s domain name.

This service is currently available only in new generic top-level domain registries.

code point

A value within the codespace of a coded character set.

In relation to domain names, code point generally refers to the unique value assigned to each character in the US-ASCII or Unicode Standard repertoire. By convention, code points in the Unicode Standard are written in hexadecimal form as shown in the following examples:

  • U+03A8 Code point for Ψ
  • U+0402 Code point for Ђ
  • U+20A5 Code point for ¥
  • U+25B7 Code point for ▷

Community Forum

The first Public Meeting in ICANN’s three-meeting annual cycle. In addition to workshops and working meetings, the Community Forum provides two Public Forums where the ICANN community can speak directly with the ICANN Board.

community objection

In the New Generic Top-Level Domain Program (New gTLD Program), an objection made 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.

Community Regional Outreach Program(CROP)

An ICANN program that provides funding to the five Regional At-Large Organizations and five Generic Names Supporting Organization constituencies to support their regional outreach and engagement efforts.

community-based generic top-level domain(community-based gTLD)

In the New Generic Top-Level Domain Program (New gTLD Program), a gTLD that is operated for the benefit of a clearly delineated community.

Competition, Consumer Trust, and Consumer Choice Review(CCT Review)

A periodic review required by the ICANN Bylaws to examine the extent to which the New Generic Top-Level Domain Program (New gTLD Program) has promoted competition, consumer trust, and consumer choice. Besides assessing the overall effectiveness of the program’s application and evaluation process, this review also evaluates the safeguards that are in place to mitigate issues that arise.

A CCT Review is performed after an application round has been in operation for one year.

Section 4.6 in the ICANN Bylaws provides details about performing a CCT Review. Reports from past reviews are available on the ICANN website, along with progress updates for any CCT Reviews that are underway.

Computer Emergency Readiness Team(CERT)

A group of experts with responsibility for protecting an organization or entity against cybersecurity threats and for responding to cybersecurity incidents when they occur. CERTs also work to improve the security and resiliency of the systems they protect.

Most countries maintain a national CERT to protect their national computing infrastructure and their governmental computing systems. In large corporations, CERTs are a standard feature in most information technology organizations.

connectivity provider

An entity that operates an Internet backbone network based on TCP/IP.

Connectivity providers maintain high-speed data routes between the Internet’s major networks and routers. Along with Internet service providers (ISPs), connectivity providers are key players in the Internet ecosphere and have essential roles in its stability and development. Within ICANN, connectivity providers are represented by the Internet Service Providers and Connectivity Providers Constituency (ISPCP) within the Generic Names Supporting Organization (GNSO).

consensus policy

A category of ICANN policies that accredited registrars and generic top-level domain registry operators are required to follow. ICANN’s agreements with these parties require compliance with stated procedures and with consensus policies. ICANN’s multistakeholder community develops consensus policies as described in the ICANN Bylaws.

Consensus Policy Implementation Framework(CPIF)

A five-stage process that the ICANN organization follows to implement policies that have been developed by the Generic Names Supporting Organization and approved by the ICANN Board of Directors. The Consensus Policy Implementation Framework is designed to support predictability, accountability, transparency, and efficiency in the implementation process.

contention set

A group of applications containing an identical or similar applied-for generic top-level domain (gTLD) string.