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Syntax Accuracy of WHOIS Data in gTLDs Presented in Accuracy Reporting System Phase I Report

24 August 2015 – ICANN today published the Phase 1 report of the WHOIS Accuracy Reporting System (ARS), which provides information about the syntax accuracy of WHOIS records in generic top-level domains (gTLDs) as compared to the requirements of the Registrar Accreditation Agreements (RAAs).

Read the Phase I report.

Using the obligations of the Registrar Accreditation Agreements to derive the syntax accuracy criteria, ICANN sought to determine whether the contact information of WHOIS records in gTLDs are meeting requirements for format and content. To do so, syntax validation was performed on a sample of WHOIS records from gTLDs. Using statistical methods, accuracy estimates with a 95% confidence interval have been provided for the population of domains in gTLDs as a whole, and for several subgroups of interest.

The analysis finds, for example, that approximately 99% of email addresses, 85% of telephone numbers and 79% of postal addresses met all syntax requirements of the 2009 RAA. See the table below for more information.

Table: Overall gTLD Conformance to 2009 RAA Requirements by Contact Mode (95% confidence interval)

  E-mail Telephone Postal Address ALL 3 Accurate
All 3 Contacts (Registrant, Technical, Administrative) Accurate 99.2% ± 0.2% 85.8% ± 0.7% 79.1% ± 0.8% 70.3% ± 0.9%

The Phase I report details the leading types of nonconformances, trends and comparisons of WHOIS accuracy across regions, RAA versions and gTLD types. The leading causes of syntax nonconformances in the various strata are presented in the Findings section of the report, as well as in the Appendices.

Next Steps for Phase 1

ICANN will host a webinar on 26 August 2015 at 15:00 UTC to provide insight into the methodology and findings of the WHOIS Accuracy Reporting System Phase I report.

Participate in the webinar.

The results of phase 1 have been provided to ICANN's Contractual Compliance team, which will assess the types of errors found and follow up with registrars on potentially inaccurate records, leading to investigation, and if needed, correction. If WHOIS inaccuracy and/or format complaints are created from the WHOIS ARS data, ICANN Contractual Compliance will issue the necessary tickets per the Contractual Compliance Approach and Process.

ICANN intends to publish the results of the Contractual Compliance efforts and solicit community feedback about the results in the fourth quarter of 2015.

Next Steps for the WHOIS ARS

In June 2015, ICANN also began work on Phase 2 of the ARS, which will measure both syntax and operability of the contact information in WHOIS records. The WHOIS ARS team has collected the initial data sample and is working to finalize the operability criteria. Testing is expected to be complete by November 2015 and a report on Phase 2 is targeted for December 2015.


ICANN reviews the WHOIS Program every three years as part of its Affirmation of Commitments. On 8 November 2012, the ICANN board approved a series of improvements to the manner in which ICANN carries out its oversight of the WHOIS Program based on recommendations made by the 2012 WHOIS Review Team. As part of these improvements, ICANN committed to proactively identifying potentially inaccurate gTLD WHOIS contact data and forwarding these records to registrars for investigation and follow up. To accomplish these tasks, ICANN initiated the development of the WHOIS Accuracy Reporting System. Throughout the development, ICANN has consulted and collaborated with the community.

The ARS is intended to lead to improvements over time in the accuracy of WHOIS data, which will be examined in subsequent ARS reports.

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Media Contact

Gwen Carlson
Director, GDD Communications
Los Angeles, CA
Tel: +1 310 578 8653


ICANN's mission is to ensure a stable, secure and unified global Internet. To reach another person on the Internet you have to type an address into your computer - a name or a number. That address has to be unique so computers know where to find each other. ICANN coordinates these unique identifiers across the world. Without that coordination we wouldn't have one global Internet. ICANN was formed in 1998. It is a not-for-profit public-benefit corporation with participants from all over the world dedicated to keeping the Internet secure, stable and interoperable. It promotes competition and develops policy on the Internet's unique identifiers. ICANN doesn't control content on the Internet. It cannot stop spam and it doesn't deal with access to the Internet. But through its coordination role of the Internet's naming system, it does have an important impact on the expansion and evolution of the Internet. For more information please visit:

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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."