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SAC 033 | Domain Name Registration Records and Directory Services

[PDF, 186 KB]

This paper is a companion document to SAC 027 Comment to GNSO regarding WHOIS studies http://www.icann.org/committees/security/sac027.pdf

The paper asserts that the WHOIS protocol and variability among WHOIS implementations contribute to the poor quality of domain name registration data currently available. The paper further asserts that the ICANN community would be served well if the accuracy and availability of domain registration information were improved.

The paper describes features and characteristics that are common to many proprietary and public directory service applications (a common data schema and authentication, authorization, auditing, accuracy and availability frameworks), and suggests a set of questions that the ICANN community could use as the basis for formulating a requirements statement for an Internet Directory Service.

This paper is informational and makes no specific recommendations. SSAC suggests that this informational paper could serve as the basis for discussions related to future WHOIS features and services.

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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."