Network Working Group Y. YONEYA Internet-Draft JPRS Intended status: BCP X. LEE Expires: September 3, 2009 CNNIC YJ. Suh NIDA E. Chen TWNIC March 2, 2009 CJK local mapping in IDNA2008 draft-jet-idnabis-cjk-localmapping-00 Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English. 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 September 3, 2009. Copyright Notice YONEYA, et al. Expires September 3, 2009 [Page 1] Internet-Draft CJK local mapping March 2009 Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Abstract Development of IDNA2008 is now in final stage. It will cause incompatibilities for Chinese, Japanese and Korean (CJK) scripts and languages. To avoid incompatibilities with IDNA2008 and current IDNA (IDNA2003), definition of specific local mapping (pre process of IDNA to be performed to IDN candidate string) for CJK is recommended. YONEYA, et al. Expires September 3, 2009 [Page 2] Internet-Draft CJK local mapping March 2009 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Positioning of this document . . . . . . . . . . . . . . . 4 1.2. Why CJK? . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. List of incompatibilities of CJK between IDNA2008 and IDNA2003 . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.1. Label separators . . . . . . . . . . . . . . . . . . . . . 5 3.2. Compatibility characters . . . . . . . . . . . . . . . . . 6 3.3. Exceptions . . . . . . . . . . . . . . . . . . . . . . . . 6 4. Solutions for incompatibilities . . . . . . . . . . . . . . . . 7 4.1. Label saparators . . . . . . . . . . . . . . . . . . . . . 7 4.2. Compatibility characters . . . . . . . . . . . . . . . . . 7 4.3. Exceptions . . . . . . . . . . . . . . . . . . . . . . . . 7 5. Guideline to keep compatibility in registration protocol . . . 7 6. Guideline to keep compatibility in domain name lookup protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7 8. Security Considerations . . . . . . . . . . . . . . . . . . . . 8 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 8 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 8 10.1. Normative References . . . . . . . . . . . . . . . . . . . 8 10.2. Informative References . . . . . . . . . . . . . . . . . . 9 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 9 YONEYA, et al. Expires September 3, 2009 [Page 3] Internet-Draft CJK local mapping March 2009 1. Introduction 1.1. Positioning of this document IDNA protocol is going to be revised by IDNA2008 ([I-D.ietf-idnabis-rationale] [I-D.ietf-idnabis-defs] [I-D.ietf-idnabis-protocol] [I-D.ietf-idnabis-tables] [I-D.ietf-idnabis-bidi]) which is in the final stage includes incompatibilities with IDNA2003 ([RFC3490] [RFC3491] [RFC3492]) in some cases. Due to those incompatibilities, name resolution of existing registered IDNs are possible to fail. To avoid such incompatibilities, IDNA2008 recommends to perform local mapping before registration and domain name lookup of IDNA processing, but it does not mention any specific method. This document defines local mapping for IDNA2008 regarding CJK to avoid incompatibilites between IDNA2008 and IDNA2003. 1.2. Why CJK? CJK shares some scripts such as Han and punctations. Therefore, it is useful to have common local mapping definition in areas and / or languages that share scripts. Furthermore, ccTLDs in CJK area are initiative of IDN because they have been actively working for IDN development and deployment since IDNA2003 start up, had published JET Guideline together, and accumulated and shared their experiences and knowledge of IDN registration and operation. Definition developed by such ccTLDs depending on their experiences is useful for community. 2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. CJK The term "CJK" stands for "Chinese, Japanese and Korean". CJK IDN The term "CJK IDN" stands for "Chinese IDN" or "Japanese IDN" or "Korean IDN". CJK scripts YONEYA, et al. Expires September 3, 2009 [Page 4] Internet-Draft CJK local mapping March 2009 +---------------------------------------+---------------+-+-+-+ | Script Name | Code(Range) |C|J|K| +---------------------------------------+---------------+-+-+-+ |CJK Symbols and Punctuation | U+3000-U+3007 |Y|Y| | |Hiragana | U+3040-U+309F | |Y| | |Katakana | U+30A0-U+30FF | |Y| | |CJK Unified Ideographs Extension A | U+3400-U+4DFF |Y| | | |CJK Unified Ideographs | U+4E00-U+9FFF |Y|Y| | |Hangul Syllables | U+AC00-U+D7A3 | | |Y| |CJK Compatibility Ideographs | U+F900-U+FAFF |Y| | | |Halfwidth and Fullwidth Forms | U+FF00-U+FFEF |Y|Y| | |CJK Unified Ideographs Extension A |U+20000-U+2A6D6|Y| | | |CJK Compatibility Ideographs Supplement|U+2F800-U+2FA1F|Y| | | +---------------------------------------+---------------+-+-+-+ Chinese IDN The term "Chinese IDN" stands for "IDN consists from CJK scripts marked with 'Y' in 'C' column and LDH". Permitted characters in Chinese IDN are listed in [IANA-IDN-Language-zh-CN] and [IANA-IDN-Language-zh-TW]. Japanese IDN The term "Japanese IDN" stands for "IDN consists from CJK scripts marked with 'Y' in 'J' column and LDH". Permitted characters in Japanese IDN are listed in [IANA-IDN-Language-ja-JP]. Korean IDN The term "Korean IDN" stands for "IDN consists from CJK scripts marked with 'Y' in 'K' column and LDH". Permitted characters in Korean IDN are listed in [IANA-IDN-Language-ko-KR]. Other terms defined in [I-D.ietf-idnabis-defs] are used. 3. List of incompatibilities of CJK between IDNA2008 and IDNA2003 3.1. Label separators Following characters are defined as label separator in IDNA2003, but not defined in IDNA2008. YONEYA, et al. Expires September 3, 2009 [Page 5] Internet-Draft CJK local mapping March 2009 +---------------------------------------+---------------+-+-+-+ | Script Name | Code |C|J|K| +---------------------------------------+---------------+-+-+-+ |IDEOGRAPHIC FULL STOP | U+3002 |Y|Y| | |HALFWIDTH IDEOGRAPHIC FULL STOP | U+FF61 |Y|Y| | |FULLWIDTH FULL STOP | U+FF0E |Y|Y| | +---------------------------------------+---------------+-+-+-+ CJK IDN which includes those characters are valid in IDNA2003 but invalid in IDNA2008. 3.2. Compatibility characters Compatibility characters that are mapped to canonical (valid) characters by Unicode Normalization Form KC (NFKC) [Unicode] [UAX15] in IDNA2003 are invalid in IDNA2008. +---------------------------------------+---------------+-+-+-+ | Script Name | Code(Range) |C|J|K| +---------------------------------------+---------------+-+-+-+ |FULLWIDTH DIGITS | U+FF10-U+FF19 |Y|Y| | |FULLWIDTH LATIN CAPITAL LETTERS | U+FF21-U+FF3A |Y|Y| | |FULLWIDTH LATIN SMALL LETTERS | U+FF41-U+FF5A |Y|Y| | |HALFWIDTH KATAKANA LETTERS | U+FF65-U+FF9F | |Y| | +---------------------------------------+---------------+-+-+-+ CJK IDN which includes those characters are valid in IDNA2003 but invalid in IDNA2008. 3.3. Exceptions Some of mark characters of quasi-Han or quasi-Kana are exceptions in IDNA2008 that have position and / or adjacent character property limitations are valid in IDNA2003. +---------------------------------------+---------------+-+-+-+ | Script Name | Code |C|J|K| +---------------------------------------+---------------+-+-+-+ |IDEOGRAPHIC ITERATION MARK | U+3006 | |Y| | |KATAKANA MIDDLEDOT | U+30FB | |Y| | +---------------------------------------+---------------+-+-+-+ CJK IDN which includes those characters are valid in IDNA2003 but happen to be invalid in IDNA2008. YONEYA, et al. Expires September 3, 2009 [Page 6] Internet-Draft CJK local mapping March 2009 4. Solutions for incompatibilities 4.1. Label saparators If characters listed in section Section 3.1 is included in CJK IDN candidate string, those characters were mapped to FULL STOP (U+002E) in local mapping processing. 4.2. Compatibility characters If characters listed in section Section 3.2 is included in CJK IDN candidate string, those characters were mapped to canonical characters by NFKC in local mapping processing. 4.3. Exceptions If characters listed in section Section 3.3 is included in CJK IDN candidate string, those characters were treated as PROTOCOL VALID instead of CONTEXTO. [NOTE: this is not local mapping, but requires property change of those characters] 5. Guideline to keep compatibility in registration protocol Registries who treat CJK IDN must implement solutions described in section Section 4. 6. Guideline to keep compatibility in domain name lookup protocol Application softwares which treat CJK IDN must implement solutions described in section Section 4. Local mappings or corresponding pre- processing must be performed on user interface (input/output) processing, such as: - User typing or pasting in input area - String extraction from free context in contents area - Displaing on dialogue and / or address bar Note that those strings are used for domain name lookup. 7. IANA Considerations None. YONEYA, et al. Expires September 3, 2009 [Page 7] Internet-Draft CJK local mapping March 2009 8. Security Considerations None. 9. Acknowledgements Many suggestions and advices were given from JET members, especially Yao Jiankang, ... 10. References 10.1. Normative References [I-D.ietf-idnabis-bidi] Alvestrand, H. and C. Karp, "An updated IDNA criterion for right-to-left scripts", draft-ietf-idnabis-bidi-03 (work in progress), November 2008. [I-D.ietf-idnabis-defs] Klensin, J., "Internationalized Domain Names for Applications (IDNA): Definitions and Document Framework", draft-ietf-idnabis-defs-06 (work in progress), February 2009. [I-D.ietf-idnabis-protocol] Klensin, J., "Internationalized Domain Names in Applications (IDNA): Protocol", draft-ietf-idnabis-protocol-09 (work in progress), February 2009. [I-D.ietf-idnabis-rationale] Klensin, J., "Internationalized Domain Names for Applications (IDNA): Background, Explanation, and Rationale", draft-ietf-idnabis-rationale-06 (work in progress), December 2008. [I-D.ietf-idnabis-tables] Faltstrom, P., "The Unicode code points and IDNA", draft-ietf-idnabis-tables-05 (work in progress), December 2008. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3490] Faltstrom, P., Hoffman, P., and A. Costello, "Internationalizing Domain Names in Applications (IDNA)", YONEYA, et al. Expires September 3, 2009 [Page 8] Internet-Draft CJK local mapping March 2009 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. [UAX15] The Unicode Consortium, "Unicode Normalization Forms", Unicode Standard Annex #15, http://www.unicode.org/reports/tr15/, 2008. [Unicode] The Unicode Consortium, "The Unicode Standard, Version 5.0", Boston, MA, USA: Addiso-Wesley. ISBN 0-321-48091-0, 2007. 10.2. Informative References [IANA-IDN-Language-ja-JP] JPRS, ".JP Japanese", IANA IDN language tables, http:// www.iana.org/domains/idn-tables/tables/jp_ja-jp_1.2.html, August 2005. [IANA-IDN-Language-ko-KR] KRNIC, ".KR Korean", IANA IDN language tables, http:// www.iana.org/domains/idn-tables/tables/kr_ko-kr_1.0.html, March 2004. [IANA-IDN-Language-zh-CN] CNNIC, ".CN Chinese", IANA IDN language tables, http:// www.iana.org/domains/idn-tables/tables/cn_zh-cn_4.0.html, March 2005. [IANA-IDN-Language-zh-TW] TWNIC, ".TW Chinese", IANA IDN language tables, http:// www.iana.org/domains/idn-tables/tables/tw_zh-tw_4.0.html, March 2005. YONEYA, et al. Expires September 3, 2009 [Page 9] Internet-Draft CJK local mapping March 2009 Authors' Addresses Yoshiro YONEYA JPRS Chiyoda First Bldg. East 13F 3-8-1 Nishi-Kanda Chiyoda-ku, Tokyo 101-0065 Japan Phone: +81 3 5215 8451 Email: yone@jprs.co.jp Xiaodong LEE CNNIC No.4 South 4th Street, Zhongguancun Beijing 100080 Peoples Republic of China Phone: +86 10 58813020 Email: lee@cnnic.cn YungJin Suh NIDA 11F, 398, Seocho-no Deocho-gu, Seoul 137-857 South Korea Phone: +82 2 2186 4562 Email: yjsuh@nida.or.kr Erin Chen TWNIC 4F-2, No.9 Sec. 2, Roosevelt Rd. Taipei 100 Taiwan Phone: +886 2 23411313#502 Email: erin@twnic.net.tw YONEYA, et al. Expires September 3, 2009 [Page 10]