Network Working Group X. LEE Internet-Draft E. CHEN Expires: July 16, 2006 J. KLENSIN N. HSU W. MAO Jan. 12, 2006 Registration and Administration Guideline for Chinese Domain Names draft-xdlee-idn-cdnadmin-06.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on July 16, 2006. Copyright Notice Copyright (C) The Internet Society (2006). Abstract Many Chinese characters in common use have variants, which makes most of the Chinese Domain Names (CDN) have at least two different forms. The equivalence between Simplified Chinese (SC) and Traditional Chinese (TC) characters is very important for CDN registration. This memo defines some basic concepts and specifies the proposed registration and administration procedure of Chinese domain names LEE, et al. Expires July 16, 2006 [Page 1] Internet-Draft Guideline for Chinese Domain Names Jan. 2006 based on the more general guidelines of RFC 3743 to avoid the problems that may be caused by the variants. It will be useful for understanding and using the tables defined in [LVT-SC] and [LVT-TC]. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1. Chinese Characters . . . . . . . . . . . . . . . . . . . . 4 2.2. Chinese Domain Name Label (CDNL) . . . . . . . . . . . . . 4 2.3. Simplified Chinese Variant Table (SCVT) . . . . . . . . . . 4 2.4. Traditional Chinese Variant Table (TCVT) . . . . . . . . . 4 2.5. Original Chinese Domain Name Label (OCDNL) . . . . . . . . 4 3. Procedure for CDNLs registration . . . . . . . . . . . . . . . 5 4. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8 Intellectual Property and Copyright Statements . . . . . . . . . . 9 LEE, et al. Expires July 16, 2006 [Page 2] Internet-Draft Guideline for Chinese Domain Names Jan. 2006 1. Introduction With the standard of Internationalized Domain Names for Application (IDNA, described in [RFC3490], [RFC3491] and [RFC3492]), non-ASCII characters are included in the DNS, and users can access Internet with their native languages, most of which are not English. However, many languages have special requirements, which are not addressed in the IDNA RFCs. For example, changes were made in the forms of a large number of Chinese characters during the last century to simplify writing and reading. These "Simplified" character have been adopted in some Chinese-speaking communities, while others continue to use the "Traditional" forms. On the global Internet, if IDNA were used alone, there would be considerable potential for confusion if the two forms were not considered together. Consequently, effective use of Chinese domain names (CDN) requires variant equivalence, as described in [RFC3743], to handle character differences between Simplified and Traditional Chinese forms. Theoretically, Chinese variant equivalence itself is very complicated (Please read [C2C] for further information). When it comes to the usage of Chinese domain names, the basic requirement is to match the user perception of Chinese characters between Simplified Chinese (SC) and Traditional Chinese (TC) forms. When users register SC/TC domain names, they do wish to obtain the traditional/simplified forms as well, and expect others to be able to access the website in both forms. This document specifies a solution for Chinese domain name registration and administration that has been adopted and deployed to manage Simplified Chinese and Traditional Chinese domain name equivalence. This solution, based on [RFC3743], is suitable for any DNS zone manager or registrar who provides Chinese domain names service. In the terminology of [RFC3743], this solution is IDL-based (Internationalized Domain Label). LEE, et al. Expires July 16, 2006 [Page 3] Internet-Draft Guideline for Chinese Domain Names Jan. 2006 2. Terminology This document adopts the terminologies that are defined in [RFC3743] and it is not possible to understand this document without first understanding its concepts and terminology, including terminology introduced in its examples. Additional terminology is defined later in this document. 2.1. Chinese Characters This document suggests permitting only a subset of Chinese characters in CDN, i.e., in the DNS. When this document discusses Chinese characters, it only refers to a subset of the characters in the first column of the tables in 3.3 and 3.4. These are defined, in detail, in [LVT-SC] and [LVT-TC]. Of course, this doesn't suggest those excluded from these tables are not Chinese characters. However, it strongly suggests that registries do not permit any registration of Chinese characters that are not listed in these tables. These tables will be updated in the future if necessary. 2.2. Chinese Domain Name Label (CDNL) If an IDN label includes at least one Chinese character, it is called a Chinese Domain Name (CDN) Label. CDN labels may contain characters from the traditional letter-digit-hyphen (LDH) set as well as Chinese characters. 2.3. Simplified Chinese Variant Table (SCVT) Based on [RFC3743], a language table for Simplified Chinese has been defined [LVT-SC]. It can be used for the registration of Simplified Chinese domain names. The key feature of this table is that the preferred variant is the SC character, which is used by Mainland China users or defined in Chinese related standards. 2.4. Traditional Chinese Variant Table (TCVT) Similarly, a language table has been defined for Traditional Chinese [LVT-TC]. It is also based on the rules of [RFC3743]. It can be used for registration of Traditional Chinese domain names. The preferred variant is the TC character, which is used in Taiwan or defined in related standards. 2.5. Original Chinese Domain Name Label (OCDNL) The CDNL that users submit for registration. LEE, et al. Expires July 16, 2006 [Page 4] Internet-Draft Guideline for Chinese Domain Names Jan. 2006 3. Procedure for CDNLs registration This document adopts the same procedure for CDNLs registration as the one defined for more general IDN labels in section 3.2.3 of [RFC3743]. The first column of SCVT is same as the first column of TCVT, so are the third columns of both tables, so the CV(IN, ZH-CN) will be same as the CV(IN, ZH-TW) after Step 3; The PV(IN, ZH-CN) is SC form, and the PV(IN, ZH-TW) is TC form. As result, there will be not more than three records, including OCDNL, SC form and TC form to be added into zone file after this procedure. The set of languages associated with IN is both ZH-CN and ZH-TW by default. The procedure for CDNL registration uses the registry- defined rules for optional processing, with the understanding that the rules may vary for different registries supporting CDNs. The motivation for such rules is described below. The preferred variant(s) is/are TC in TCVT, and SC in SCVT. There may be more than one preferred variant for a given valid character. In actuality, while IDNA, and hence [RFC3743], look at characters one at a time, the actual relationship between the valid code point and the preferred variant is contextual: whether one character can be substituted for another depends on the characters with which it is associated in a label or, more generally, in a phrase. In particular, some of the preferred variants make no sense in combination with other characters; therefore, those combinations should not be added into the Zone file as ZV. If desired, it should be possible to define and implement rules to reduce the preferred variant labels to only plausible ones. This could be done, for example, with some artificial intelligence tools, or with feedback from the registrant, or with selection based on frequency of occurrence in other texts. To illustrate one possibility, the OCDNL could be required to be TC-only or SC-only, and if there are more than one preferred variants, the OCDNL will be used as the PV, instead of PV produced by the algorithm. To reemphasize, the tables in [LVT-SC] and [LVT-TC] follow the table format and terminologies defined in [RFC3743]. If one intends to implement Chinese domain names registration based on these two tables or ones similar to them, a complete understanding of [RFC3743] is needed for the proper use of those tables. LEE, et al. Expires July 16, 2006 [Page 5] Internet-Draft Guideline for Chinese Domain Names Jan. 2006 4. Security Considerations This document is subject to the same security considerations as [RFC3743], which defines the table formats and operations. As with that base document, part of its intent is to reduce the security problems that might be caused by confusion among characters with similar appearances or meanings. While it will not introduce any additional security issues, additional registration restrictions such as those outlined in section 3 may further help reduce potential problems. LEE, et al. Expires July 16, 2006 [Page 6] Internet-Draft Guideline for Chinese Domain Names Jan. 2006 5. Acknowledgements Thanks for these person's suggestions, promotions and efforts on such tough work: WANG YanFeng, Ai-Chin LU, Shian-Shyong TSENG, QIAN HuaLin, and Li-Ming TSENG. Especially, thanks Joe ZHANG and XiaoMing WANG for their outstanding contributions on SCVT in [LVT-SC]. And also thanks Kenny HUANG, Zheng-Wei LIN, Shi-Xiong TSENG, Lie-Neng WU, Cheng-Wu PAN, Lin-Mei WEI, Qi-Qing HSU for their efforts and contributions on editing the TCVT in [LVT-TC]. These experts provided basic materials, or gave very crucial suggestions and principles to accomplish these two variant tables. And that, the authors gratefully acknowledge the contributions of those who commented and make suggestions on this document, including James SENG, and other JET members. 6. References [C2C] Halpern, J. and J. Kerman, "Pitfalls and Complexities of Chinese to Chinese Conversion", International Unicode Conference (14th) in Boston, March 1999. [LVT-SC] QIAN, H. and X. LEE, ".CN Chinese Character Table", IANA IDN Languages Tables, March 2005. [LVT-TC] LU, A., ".TW Traditional Chinese Character Table", IANA IDN Languages Tables, March 2005. [RFC3490] Faltstrom, P., Hoffman, P., and A. Costello, "Internationalizing Domain Names in Applications (IDNA)", RFC 3490, March 2003. [RFC3491] Hoffman, P. and M. Blanchet, "Nameprep: A Stringprep Profile for Internationalized Domain Names (IDN)", RFC 3491, March 2003. [RFC3492] Costello, A., "Punycode: A Bootstring encoding of Unicode for Internationalized Domain Names in Applications (IDNA)", RFC 3492, March 2003. [RFC3743] KONISHI, K., HUANG, K., QIAN, H., and Y. KO, "Joint Engineering Team (JET) Guidelines for Internationalized Domain Names (IDN) Registration and Administration for Chinese, Japanese, and Korean", RFC 3743, April 2004. LEE, et al. Expires July 16, 2006 [Page 7] Internet-Draft Guideline for Chinese Domain Names Jan. 2006 Authors' Addresses LEE Xiaodong CNNIC, No.4 South 4th Street, Zhongguancun Beijing 100080 Phone: +86 10 58813020 Email: lee@cnnic.cn URI: http://www.cnnic.cn Erin CHEN TWNIC, 4F-2, No. 9, Sec. 2, Roosevelt Rd. Taipei 100 Phone: +886 2 23411313 Email: erin@twnic.net.tw URI: http://www.twnic.net.tw John C KLENSIN 1770 Massachusetts Ave, #322 Cambridge, MA 02140 USA Phone: +1 617 491 5735 Email: john+ietf@jck.com Nai-Wen HSU TWNIC, 4F-2, No. 9, Sec. 2, Roosevelt Rd. Taipei 100 Phone: +886 2 23411313 Email: snw@twnic.net.tw URI: http://www.twnic.net.tw MAO Wei CNNIC, No.4 South 4th Street, Zhongguancun Beijing 100080 Phone: +86 10 58813055 Email: mao@cnnic.cn URI: http://www.cnnic.cn LEE, et al. Expires July 16, 2006 [Page 8] Internet-Draft Guideline for Chinese Domain Names Jan. 2006 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org. Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Copyright Statement Copyright (C) The Internet Society (2006). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. LEE, et al. Expires July 16, 2006 [Page 9]