[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

CVS libidn/doc/specifications

From: libidn-commit
Subject: CVS libidn/doc/specifications
Date: Thu, 12 Jan 2006 22:44:43 +0100

Update of /home/cvs/libidn/doc/specifications
In directory dopio:/tmp/cvs-serv418/doc/specifications

Added Files:
Log Message:

--- /home/cvs/libidn/doc/specifications/draft-xdlee-idn-cdnadmin-06.txt 
2006/01/12 21:44:43     NONE
+++ /home/cvs/libidn/doc/specifications/draft-xdlee-idn-cdnadmin-06.txt 
2006/01/12 21:44:43     1.1

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

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-

   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

   The list of Internet-Draft Shadow Directories can be accessed at

   This Internet-Draft will expire on July 16, 2006.

Copyright Notice

   Copyright (C) The Internet Society (2006).


   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

   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

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

   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

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

[106 lines skipped]

reply via email to

[Prev in Thread] Current Thread [Next in Thread]