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Expedited Registry Security Request (ERSR)

Open: 1 October 09
Closed: 1 November 09 Extended to 16 November 09

Explanation/Background: The Expedited Registry Security Request (ERSR) is the result of a collaborative effort between ICANN and gTLD registries to develop a process for quick action in cases where gTLD registries inform ICANN of a present or imminent security incident to their TLD and/or the DNS and request a contractual waiver for actions they might take or have taken to mitigate or eliminate the incident. A contractual waiver is an exemption from compliance with a specific provision of the Registry Agreement for the time period necessary to respond to the Incident. The ERSR process is viewable at

Public comment is sought on the ERSR process.

Staff member responsible: Craig Schwartz

Announcement | Comments | Summary/analysis of comments

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."