Afilias supports multiple Internationalized Domain Name (IDN) scripts within the .INFO domain. These standards-compliant IDNs have been made available to address the rising international need for the Internet to evolve to support non-English speakers. This document provides background information to enhance understanding of .INFO IDNs.

International characters must be converted to ASCII
Due to the technical limitations of the Internet, domain names can only be registered in ASCII, otherwise known as plain text. International characters such as ü, ç, or Ф, cannot be interpreted by the DNS and therefore cannot reside in a domain name registry as a registered name.

'Punycode' is an international standard adopted in 2003 for converting these characters into ASCII. It provides a mechanism for words with non-ASCII characters to be represented at a domain registry in ASCII format, but used by the general public in their expected native form.

'Punycode' is used to translate the word containing international characters into an ASCII string that can be registered by a domain name registry and resolved through the DNS.

To convert IDNs to ASCII, the international characters must first be mapped to ASCII, e.g.: the ü in probestück.info is converted to the ASCII string "w9a." Then a prefix is added to the name, in the case of the approved standard 'punycode', the prefix is "xn--". So the resulting ASCII name for the IDN probestück.info is xn--probestck-w9a.info.

This conversion process is completed by registrars who use the Nameprep and Stringprep specifications from the IETF to prepare names for submission to Afilias. The registry actually reserves the 'punycode' representation of the domain, and IDN compliant applications make the appropriate translation to and from the user.

User accessibility of IDN names through browsers
When a user types an IDN into a browser, the application must know how to convert the name into 'punycode' for it to be handled properly by the registry. There are already some commercial browsers that are compliant with the international 'punycode' standard. These include the most recent versions of Netscape, Mozilla, Opera, and Internet Explorer 7; there may be others.

In these browsers, when a user types in an IDN name, e.g.: probestück.info, the browser uses the Nameprep and Stringprep specifications to translate the name into the 'punycode' string xn--probestck-w9a.info. The browser then sends this 'punycode' string to Afilias' .INFO TLD nameserver where the name is looked up in the zone file. Then the TLD nameserver responds with either "YES" this name exists, or "NO" this name does not exist (i.e.: NX domain record). If the name exists, then the user will automatically go to the Web site for probestück.info. If the answer is NO, then the user will get a NX domain response or the error "this domain does not exist."

For users working with a browser that does not support 'punycode', the browser cannot translate the name, e.g.: probestück.info, into 'punycode', so the request reaches the registry in an unintelligible format (e.g. it still has a ü). Since the nameserver does not recognize the submission from a non IDN-compliant browser it cannot look up the name probestück.info which has no matching entry in the zone file (Note: the zone file only contains the 'punycode' version of the IDN). So the user will receive a negative response from the TLD nameserver, a NX domain response - or "this domain does not exist." Users who anticipate using non-ASCII characters extensively should ensure that their applications are IDNA compliant.

Afilias' solution
Afilias' solution follows the international "punycode" standard. This means that Afilias' IDNs will work in IDNA-compliant applications, but they will not work in applications that are not yet compliant with the standard. The browsers noted above, for example, are IDNA compliant already.

While it may be some time before all major applications have adopted the standard, Afilias encourages registrants to reserve names now in anticipation of the expected broad scale adoption of the standard. The establishment of 'punycode' as the standard, and Afilias' adherence to it, ensures the value of .INFO IDNs. As these standards become ubiquitous, the Internet will complete its evolution to support international language characters.