Skip to main content

Welcome to the new ICANN.org! Learn more, and send us your feedback. Dismiss

Resources

SSAC Presentations

Display and Usage of Internationalized Registration Data, Webinar
(16 September 2009) [PDF]

SSAC Open Meeting presentations, ICANN Mexico City
(2 March 2009) [PDFs]

SSAC Open Meeting presentations, ICANN Cairo
(3 November 2008) [PDFs]

SSAC Open Meeting presentations, ICANN Paris
(23 June 2008) [PDFs]

SSAC Public Forum Report, Los Angeles, CA
(2 November 2007) [PDF]

ICANN SSAC Workshop, Los Angeles, CA: Domain Name Front Running
(30 October 2007) [PDF]

Presentation: Survey of IPv6 Support among Commercial Firewalls
(28 October 2007) [PDF]

ICANN GNSO WHOIS Workshop, Los Angeles, CA: Is the WHOIS service a source for email addresses for spammers?
(28 October 2007) [PDF]

SSAC Summary for Public Forum
(28 June 2007) [PDF]

SSAC Report on Estonia DDoS Attacks
(25 June 2007) [PDF]

ICANN SSAC Workshop, Marrakech, MA
(25 June 2006) [PDF]

SSAC Briefing to the GAC
(25 June 2007) [PDF]

ICANN SSAC Workshop, Wellington, NZ
(28 March 2006) [PDF]

ICANN SSAC Workshop, Vancouver, CA
(29 November 2005) [PDF]

ICANN SSAC Workshop, Luxembourg City, LU
(12 July 2005) [PDF]

ICANN SSAC Workshop, Mar del Plata, AR
(5 April 2005) [PDF]

ICANN Public Forum, Bucharest, RO
(27 June 2002) [Postscript]

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""icann.org"" is not an IDN."