Network Working Group HF. Zhu Internet Draft: Chinese Character Encoding Tsinghua U Document: internet-drafts/draft-zhu-apng-cc-encoding-v2-00.txt DY. Hu Tsinghua U ZG. Wang CITS TC. Kao III WC. Chang III M. Crispin U Washington July 1995 Chinese Character Encoding for Internet Messages Status of this Memo This document is an Internet-Draft. 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." To learn the current status of any Internet-Draft, please check the "1id-abstracts.txt" listing contained in the Internet-Drafts Shadow Directories on ds.internic.net (US East Coast), nic.nordu.net (Europe), ftp.isi.edu (US West Coast), or munnari.oz.au (Pacific Rim). This is a draft document of APNG-CC, the Chinese Character sub-working group of the I18N/L10N (Internationalization and Localization) working group of APNG (Asia-Pacific Networking Group). A revised version of this draft document will be submitted to the RFC editor as an Informational RFC for the Internet Community. Discussion and suggestions for improvement are requested, and should be sent to apng-cc@apng.org or zhf@net.edu.cn (the coordinator). This document has the same content as draft-zhu-apng-cc-encoding-v1-00.txt, but is written in a different way and will expire before Febuaray 1996. Distribution of this memo is unlimited. Abstract This memo provides methods for transporting Chinese characters through, but not limited to, electronic mail [RFC-822] and network news [RFC-1036] in the Internet community. Introduction As the use of Internet covers more and more Chinese people in the world, the need has increased for the ability to send documents containing Chinese characters on the Internet. The methods described in this document provide means of transporting existing Chinese character sets as well as leaving sufficient space for future extension. This document describes three kinds of encodings: 1. ISO-2022-CN and ISO-2022-CN-EXD 2. CN-GB and CN-Big5 series 3. ISO-10646 and Unicode ISO-2022-CN is based upon ISO-2022 [ISO-2022], similar to earlier work on ISO-2022-JP [RFC-1468] and ISO-2022-KR [RFC-1557] for Japanese and Korean languages. It is 7-bit, and supports both simplified Chinese characters using GB-2312-80 [GB-2312] and traditional Chinese characters using the first two planes of CNS-11643 [CNS-11643], as well as ASCII [ASCII] characters. ISO-2022-CN-EXD is an extended form of ISO-2022-CN that additionally supports other GB character sets and all planes of CNS-11643. CN-GB and CN-Big5 series character sets are 8-bit, and reflect common domestic usage of email on both sides of the Taiwan Straits. ISO-10646 and Unicode are 8-bit character sets, based on the usage of ISO/IEC-10646 [ISO-10646] and Unicode [Unicode 1.1]. Specification 1. 7-bit MIME character sets: ISO-2022-CN and ISO-2022-CN-EXD 1.1 Description Since ISO-2022-CN and ISO-2022-CN-EXD are 7-bit encodings, they do not require the 8-bit SMTP extensions. ISO-2022-CN-EXD could be used to support Big-5 [Big-5] too, while ISO-2022-CN can also support almost all the characters in Big-5 (except two seldom-used characters). <> 1.2 ISO-2022-CN The starting code of ISO-2022-CN is ASCII. ASCII and Chinese characters are distinguished by the use of designations (ESC sequences) and shift functions. For example, once the sequence ESC $ ) A (four bytes, hexadecimal values: 1B 24 29 41) appears, in the upcoming bytes, the bytes followed SO (one byte, hexadecimal value 0E) are Chinese characters as defined in GB-2312-80. To shift back to ASCII, SI (one byte, hexadecimal value 0F) should be used, the bytes followed SI are ASCII characters. Here, the ESC $ ) A is called designation, and SI, SO are shift functions. Designations define the Chinese character sets used in the text. There are three kinds of designations: SOdesignation, SS2designation and SS3designation. The SOdesignation is in the form ESC $ ) , where < F> is the "final character" assigned to the character set by ISO (refer to the ISO registry [ISOREG] for more details). The SS2designatin is in the form ESC $ * , and the SS3designation is in the form ESC $ + < F> . A designation overrides any previous designation for subsequent octects in the text. There are four kinds of shifts: SI, SO, SS2 and SS3. The shift SI (an octet with hexadecimal value 0F) declares that subsequent octets are interpreted in ASCII. The shift SO (an octect with hexadecimal value 0E) declares that subsequent octets are interpreted in the character set defined by SOdesignation. The shift SS2 (two octets with hexadecimal values 1B 4E) declares that the subsequent two octets are interpreted in the character set defined by SS2designation, after which the previous interpretation (from SI or SO) is restored. The shift SS3 (two octets with hexadecimal values 1B 4F) declares that the subsequent two octets are interpreted in the character set defined by SS3designation, after which the previous interpretation (from SI or SO) is restored. Another example, the sequence ESC $ ) G indicates bytes followed SO are Chinese characters from CNS-11643-plane1, until another SOdesignation appears. The sequence ESC $ * H indicates the two bytes immediately followed SS2 represent a character in CNS-11643-plane2, until another SS2designation is met. The escape sequence, shift function and character set used in an ISO-2022-CN text are as follows: Character sets Shift in with -------------------------------------------------------------------- ASCII SI GB-2312, CNS-11643-plane1 SO CNS-11643-plane2 SS2 ESC $ ) A Indicates the bytes followed SO are Chinese characters as defined in GB-2312-80, until another SOdesignation appears ESC $ ) G Indicates the bytes followed SO are as defined in CNS-11643-plane1, until another SOdesignation appears ESC $ * H Indicates the two bytes immediately followed SS2 is a Chinese character as defined in CNS-11643-plane2, until another SS2designation appears If there are any GB or CNS characters on a line, there must be a shift to ASCII before the end of the line (i.e., before the CRLF), because the next line starts in the character set that was shifted to before the end of the previous line. In other words, each line starts in ASCII, and ends in ASCII. The name given to this character encoding is "ISO-2022-CN". This name is intended to be used as the "charset" parameter in MIME messages. Content-Type: text/plain; charset=iso-2022-cn The ISO-2022-CN encoding is already in 7-bit form, so it is not necessary to use a Content-Transfer-Encoding header. ISO-2022-CN may also be used in MIME2 headers. Other restrictions are given in the Formal Syntax of ISO-2022-CN. 1.3 ISO-2022-CN-EXD ISO-2022-CN is a subset of ISO-2022-CN-EXD. ISO-2022-CN-EXD supports all characters in existing GB and CNS-11643 character sets. The escape sequence, shift function and character set used in an ISO-2022-CN-EXD text are as follows: Character sets Shift in with -------------------------------------------------------------------- ASCII SI GB-2312, GB-12345, CNS-11643-plane1, GB-2312+GB-8565 SO GB-7589, GB-13131, CNS-11643-plane2 SS2 GB-7590, GB-13132 or other new GBs,CNS-11643-plane3 or SS3 other planes of CNS-11643 Note: Currently, there are some GB sets that have not been registered in ISO. Here represents the final character that will be assigned by ISO for those sets. ESC $ ) A Indicates the bytes followed SO are Chinese characters as defined in GB-2312-80, until another SOdesignation appears ESC $ * Indicates the two bytes immediately followed SS2 is a Chinese character as defined in GB-7589-87 [GB-7589], until another SS2designation appears ESC $ + Indicates the two bytes immediately followed SS3 is a Chinese character as defined in GB-7590-87 [GB-7590], until another SS3designation appears ESC $ ) Indicates the bytes followed SO are as defined in GB-12345-90 [GB-12345], until another SOdesignation appears ESC $ * Indicates the two bytes immediately followed SS2 is a Chinese character as defined in GB-13131-91 [GB-13131], until another SS2designation appears ESC $ + Indicates the two bytes immediately followed SS3 is a Chinese character as defined in GB-13132-91 [GB-13131], until another SS3designation appears ESC $ ) E Indicates the bytes followed SO are as defined in GB-2312+ GB-8565 [GB-8565], until another SOdesignation appears ESC $ ) G Indicates the bytes followed SO are as defined in CNS-11643-plane1, until another SOdesignation appears ESC $ * H Indicates the two bytes immediately followed SS2 is a Chinese character as defined in CNS-11643-plane2, until another SS2designation appears ESC $ + I Indicates the immediate two bytes followed SS3 is a Chinese character as defined in CNS-11643-1992-plane3, until another SS3designation appears ESC $ + J Indicates the immediate two bytes followed SS3 is a Chinese character as defined in CNS-11643-1992-plane4, until another SS3designation appears ESC $ + K Indicates the immediate two bytes followed SS3 is a Chinese character as defined in CNS-11643-1992-plane5, until another SS3designation appears ESC $ + L Indicates the immediate two bytes followed SS3 is a Chinese character as defined in CNS-11643-1992-plane6, until another SS3designation appears ESC $ + M Indicates the immediate two bytes followed SS3 is a Chinese character as defined in CNS-11643-1992-plane7, until another SS3designation appears Same as ISO-2022-CN, each line should start in ASCII, and end in ASCII. The name given to this character encoding is "ISO-2022-CN-EXD". This name is intended to be used as the "charset" parameter in MIME messages. Content-Type: text/plain; charset=iso-2022-cn-exd The ISO-2022-CN-EXD encoding is also in 7-bit form, so it is not necessary to use a Content-Transfer-Encoding header. ISO-2022-CN-EXD may also be used in MIME2 headers. Other restrictions are given in the Formal Syntax of ISO-2022-CN-EXD. 1.4 Support Big-5 with ISO-2022-CN and ISO-2022-EXD <> 2. 8-bit MIME character sets: CN-GB, CN-Big5 series The CN-GB,CN-Big5 series of charset names are given below. Among other things, these support current practice; specifically, CN-GB reflects the current usage for simplified Chinese e-mail, and CN-Big5 reflects the current usage for traditional Chinese e-mail. Note: the use of 8-bit character sets requires the use of either an 8-to-7 Content-Transfer-Encoding mechanism such as "BASE64" or "QUOTED-PRINTABLE" if the network is not 8-bit clean, or the 8-bit SMTP extensions [SMTPEXT] with the "8BIT" Content-Transfer-Encoding on 8-bit clean networks. Otherwise, an 8-bit message which passes through a 7-bit mailer is likely to have the 8th bit truncated, resulting in an unreadable message. Although "just send 8-bit data" has been common practice in the past, it is incorrect according to the Internet standards and causes interoperability problems. 2.1 CN-GB and CN-GB-xxxxx-xx E-mail using GB characters is sent in this way: GB-2312-80 characters are used with ASCII characters, not GB-1988-80 [GB-1988]. GB-2312-80 is also 7-bit, to avoid conflicting with ASCII. If the character is from GB-2312-80, the MSB (bit-8) of each byte is set to 1, and therefore becomes a 8-bit character. Otherwise, the byte is interpreted as ASCII. This constructs a character set named "GB Internal Code". This method is alos adopted in the .gb files in the Internet. To use this character scheme with MIME, CN-GB is used as the value for the charset parameter: Content-Type: text/plain; charset=cn-gb There are character sets other than GB-2312-80 in GB. They can be used with the format of CN-GB-xxxxx-xx, in which xxxxx is the GB standard number, and xx is the year of edition. They should be coded in 8-bit as CN-GB. Currently, these GB standards are GB-7589-87, GB-7590-87, GB-12345-90, GB-13131-91 and GB-13132-91. GB-7589-87 and GB-7590-87 supplement the simplified characters in GB-2312-80. Each character in GB-12345-90, GB-13131-91, and GB-13132-91 are traditional Chinese characters that correspond to the character in GB-2312-80, GB-7589-87, and GB-7590-87 with the same code. Therefore, their "charset" names should be CN-GB-7589-87,CN-GB-7590-87, CN-GB-12345-90, CN-GB-13131-91 and CN-GB-13132-91. There is also a kind of dependent character set that can only be used with one of the above sets. For example, if GB-8565 is used, it can only be used with GB-2312 or GB-12345, in this case, "+" is permitted to appear in the charset name, i.e. CN_GB-2312-80+GB-8565-88. CN-GB and CN-GB-xxxxx-xx may also be used in MIME2 headers. To avoid hindering interoperability, CN-GB is encouraged to be used whenever possible. 2.2 CN-Big5 and CN-Big5-- BIG-5 is a character set of traditional Chinese characters, widely used in Taiwan and overseas. E-mail using BIG-5 characters is sent in this way: BIG-5 characters are used with ASCII characters. BIG-5 is a two-byte coding, in which the first byte is 7-bit, and the second byte is 8-bit. If the character is from BIG-5, the MSB (bit-8) of the first byte is set to 1, and therefore becomes an 8-bit character. Otherwise, the byte is interpreted as ASCII. (Big-5 uses the code space: [0xa1-0xfe,0x40-0x7e] and [0xa1-0xfe,0xa1-0xfe], and two other user areas with the first byte in the range of [0x81-0xa0].) To use this character scheme with MIME, CN-Big5 is used as the value for the charset parameter: Content-Type: text/plain; charset=cn-big5 The and indicates manufacturer's version and year of edition which some implementations might want to check. These are optional. CN-Big5 and CN-Big5-- may also be used in MIME2 headers. To avoid hindering interoperability, CN-Big5 is encouraged to be used whenever possible (as opposed to a variant). 3. 8-bit MIME character sets: Unicode, ISO-10646 Many Chinese characters are supported by Unicode, ISO-10646. They can also be transferred in Unicode or 10646 forms. For details of using Unicode with MIME, refer to RFC-1641 [RFC-1641], RFC-1642[RFC-1642]. For assigned names for 10646 sets, refer to RFC-1700 [RFC-1700]. Background Information 1. Use of Chinese in Chinese-speaking nations and regions The mainland provinces of China use simplified Chinese character in daily life. GB is the standard electronic character set. It is the main means for communications between people who share simplified Chinese characters in the world. Taiwan uses traditional Chinese characters in daily life. Big-5 is a widely-used character set of traditional Chinese characters, and the de-facto industrial standard in Taiwan, while CNS-11643 is a formal way for information interchange. Hong Kong uses traditional Chinese characters in daily life, but uses both GB and Big-5 in electronic form, because Hong Kong people often communicate with people in all of China's provinces. Singapore seldom uses Chinese characters, and uses the simplified form when Chinese characters are used. In electronic form, Unicode is more popular, however GB is also used. 2. About ISO-2022-CN and ISO-2022-CN-EXD ISO-2022-CN and ISO-2022-CN-EXD encodings are based on the usage of ISO 2022. 3. Miscellaneous about Chinese character sets The GB-1988-80 character set is identical to ISO 646 [ISO-646] except for currency symbol and tilde. The currency symbol and the tilde are replaced by the Yuan sign and a short line. This set is GB's variant of ISO 646. This character set and CNS-5205 [CNS-5205] are not encouraged for use in the Internet, since ASCII combined with GB-2312 or CNS-11643-plane 1 and plane 2 comprises all characters in them. The GB-2312-80 character set consists of simplified Chinese characters, digits, Latin, Greek and Russian alphabets, and some other symbols; in all, 7445 characters. Each character is two bytes. CNS-11643 is a character set used in Taiwan. It contains several character planes (sub-character sets) arranged as an 94x94 character set for each plane. Plane 1 and Plane 2 contain nearly the same characters as the Big-5 character set and the same code sequences, with some additional symbols. <> 4. Miscellaneous implementation information For maximum interoperability, implementations SHOULD at least support sending and receiving ISO-2022-CN. Supportting all registered character sets in ISO-2022-CN-EXD is greatly encouraged. It is also better to be able to support CN-GB (the status quo for simplified Chinese e-mail ) and CN-Big5 (the status quo for traditional Chinese e-mail). But sending ISO-2022-CN message is always encouraged whenever possible. To the maximum extent possible, implementations should be capable of displaying messages in any of the encodings introduced in this document, even if they only transmit messages in one form. Ideally, this would be done by shifting to the appropriate font (e.g. on X-windows displays) but suitable translation tables may also be used. <> The human user (not implementor) should try to keep lines within 80 display columns, or, preferably, within 75 (or so) columns, to allow insertion of ">" at the beginning of each line in excerpts. Each Chinese character takes up two columns, and the shift sequences do not take up any columns. The implementor is reminded that Chinese characters take up two bytes and should not be split in the middle to break lines for displaying, etc. X.400 Considerations X.400 has the ability of carrying different character sets in a message by using the body part "GeneralText" defined by ISO/IEC-10021-7. [ISO-10021]. The X.400 ASN.1 definition of the GeneralText body part is: general-text-body-part EXTENDED-BODY-PART-TYPE PARAMETERS GeneralTextParameters IDENTIFIED BY id-ep-general-text DATA GeneralTextData ::= id-et-general-text GeneralTextParameters ::= SET OF CharacterSetRegistration CharacterSetRegistration ::= INTEGER (1..32767) GeneralTextData ::= GeneralString Therefore, using ISO-2022-CN simply set the "CharacterSetRegistration" part as 6,58,171,172. <> Similiarly, using ISO-2022-CN-EXD should set the registered numbers of all character sets in the "CharacterSetRegistration" part. For the registered numbers, please refer to ISO registry. Besides character sets supported by ISO-2022-CN, currently registered numbers are: GB-2312+GB-8565: ??? CNS-11643-plane-3: ??? CNS-11643-plane-4: ??? CNS-11643-plane-5: ??? CNS-11643-plane-6: ??? CNS-11643-plane-7: ??? For ISO-10646 and Unicode, <> For CN-GB and CN-Big5 series of character sets, currently there is no formal methods that could be used in X.400 yet. For detail about X.400 use of character sets, please refer to RFC-1502 [RFC-1502]. Formal Syntax of ISO-2022-CN and ISO-2022-CN-EXD 1. Formal Syntax of ISO-2022-CN The notational conventions used here are identical to those used in RFC 822. body ::= *e_line *( *designator *( e_line / h_line )) designator ::= SOdesignator / SS2designator / SS3designator SOdesignator ::= ESC "$" ")" final_char SS2designator ::= ESC "$" "*" final_char SS3designator ::= ESC "$" "+" final_char final_char ::= final_char_gb / final_char_cns final_char_gb ::="A" final_char_cns ::= "G" / "H" e_line ::= *text CRLF h_line ::= *text 1*( segment *text ) CRLF segment ::= ( SO / SS2 / SS3 ) 1*(one_of_94 one_of_94) SI ; ( Octal, Decimal.) ESC ::= ; ( 33, 27.) SI ::= ; ( 17, 15.) SO ::= ; ( 16, 14.) SS2 ::= ; ( 33 116, 27 78.) SS3 ::= ; ( 33 117, 27 79.) SP ::= ; ( 40, 32.) one_of_94 ::= ; (41-176, 33-126.) CHAR ::= ; ( 0-177, 0.-127.) text ::= 2. Formal Syntax of ISO-2022-CN-EXD The notational conventions used here are identical to those used in RFC 822. body ::= *e_line *( *designator *( e_line / h_line )) designator ::= SOdesignator / SS2designator / SS3designator SOdesignator ::= ESC "$" ")" final_char SS2designator ::= ESC "$" "*" final_char SS3designator ::= ESC "$" "+" final_char final_char ::= final_char_gb / final_char_cns final_char_gb ::="A" / "E" / final_char_cns ::= "G" / "H" / "I" / "J" / "K" / "L" / "M" e_line ::= *text CRLF h_line ::= *text 1*( segment *text ) CRLF segment ::= ( SO / SS2 / SS3 ) 1*(one_of_94 one_of_94) SI ; ( Octal, Decimal.) ESC ::= ; ( 33, 27.) SI ::= ; ( 17, 15.) SO ::= ; ( 16, 14.) SS2 ::= ; ( 33 116, 27 78.) SS3 ::= ; ( 33 117, 27 79.) SP ::= ; ( 40, 32.) one_of_94 ::= ; (41-176, 33-126.) CHAR ::= ; ( 0-177, 0.-127.) text ::= References [ASCII] American National Standards Institute, "Coded character set -- 7-bit American National Standard Code for Information Interchange", ANSI X3.4-1986. [BIG-5] Institute for Information Industry, " Chinese Coded Character Set in Computer ", March, 1984 [CNS-5205] "Information processing -- 7-Bit Coded Character Set For Information Interchange", CNS-5205. [CNS-11643] "Chinese Standard Interchange Code", CNS-11643 version 1992; "Standard Interchange Code for Generally-Used Chinese Characters", CNS-11643 version 1986. [GB-1988] "7-bit Coding Character Set for Information Interchange", GB-1988-80. [GB-2312] "Coding of Chinese Ideogram Set for Information Interchange Basic Set", GB-2312-80. [GB-7589] "Code of Chinese Ideograms Set for Information Interchange, the 2nd Supplementary Set", UDC 681.3.048, GB 7589-87. [GB-7590] "Code of Chinese Ideogram Set for Information Interchange, the 4th Supplementary Set",UDC 681.3.048, GB 7590-87. [GB-8565] "Information Processing Coded Character Sets for Text Communication", UDC 681.3, GB-8565-88. [GB-12345] "Code of Chinese Ideogram Set for Information Interchange Supplementary Set", GB/T 12345-90. [GB-13131] "Code of Chinese Ideogram Set for Information Interchange, the 3rd Supplementary Set", GB-13131-91. [GB-13132] "Code of Chinese Ideogram Set for Information Interchange, the 5th Supplementary Set", GB-13132-91. [ISO-646] International Organization for Standardization (ISO), "Information technology -- ISO 7-bit coded character set for information interchange", International Standard, Ref. No. ISO/IEC 646:1991. [ISO-2022] International Organization for Standardization (ISO), "Information processing -- ISO 7-bit and 8-bit coded character sets -- Code extension techniques", International Standard, Ref. No. ISO 2022-1986 (E). [ISO-10021] Information Technology - Text communication - Message-Oriented Text Interchange Systems (MOTIS), ISO 10021, October 1988. [ISO-10646] ISO/IEC 10646-1:1993(E) Information Technology--Universal Multiple-octet Coded Character Set (UCS). [ISOREG] International Organization for Standardization (ISO), "International Register of Coded Character Sets To Be Used With Escape Sequences". [MIME-1] Borenstein, N., and Freed, N., "MIME (Multipurpose Internet Mail Extensions) Part One: Mechanisms for Specifying and Describing the Format of Internet Message Bodies", RFC 1521, Bellcore, Innosoft, September 1993. [MIME-2] Moore, K., "MIME (Multipurpose Internet Mail Extensions) Part Two: Message Header Extensions for Non-ASCII Text", RFC 1522, University of Tennessee, September 1993. [RFC-822] Crocker, D., "Standard for the Format of ARPA Internet Text Messages", STD 11, RFC 822, University of Delaware, August 1982. [RFC-1036] Horton M., and Adams, R., "Standard for Interchange of USENET Messages", RFC 1036, AT&T Bell Laboratories, Center for Seismic Studies, December 1987. [RFC-1468] Murai J., Crispin M. and E. van der Poel, Japanese Character Encoding for Internet Messages, June 1993. [RFC-1557] Choi U., Chon K. and Park H., Korean Character Encoding for Internet Messages, December 1993. [RFC-1641] Goldsmith D., and Davis M., "Using Unicode with MIME", RFC 1641, Taligent Inc., July 1994 [RFC-1642] Goldsmith D., and Davis M.," UTF-7, A Mail-Safe Transformation Format of Unicode", July 1994 [RFC-1700] Reynolds J., and Postel J., "Assigned Numbers",RFC 1700, STD 2, ISI, October 1994 [SMTP] Postel, Jonathan B. "Simple Mail Transfer Protocol", STD 10, RFC 821, USC/Information Sciences Institute, August 1982. [SMTPEXT] Klensin, J.; Freed, N.; Rose, M.; Stefferud, E.; and Crocker, D., "SMTP Service Extensions", RFC 1651, July 1994. [Unicode 1.1] "The Unicode Standard, Version 1.1": Version 1.0, Volume 1 (ISBN 0-201-56788-1), Version 1.0, Volume 2 (ISBN 0-201-60845-6), and "Unicode Technical Report #4, The Unicode Standard, Version 1.1" (available from The Unicode Consortium, and soon to be published by Addison-Wesley). Acknowledgments This document is the result of cooperation in the APNG-CC, the Chinese Character sub-working group of the I18N/L10N (Internationalization and Localization) working group of APNG (Asia-Pacific Networking Group). The membership of APNG-CC consists of individuals from both sides of the Taiwan Strait, HongKong, and from Singapore and other countries. The authors wish to thank all members of APNG-CC. Prof.Yao Shiquan and Ms.Lin Ning of CITS (China Information Technology Standardization Technical Committee), Prof. Zhao Jingrong, Prof. Li Xing, and Mr.YouYue of Tsinghua University gave many help in the process of the work. Many thanks to Mr. C.J.Cherng and Mr. C.K.Fan of III (Institute for Information Industry), and Mr. Chang JingShin from Tsinghua University in Hsinchu, Taiwan. In particular, Mr.Masataka Ohta, who is the coordinator of APNG-I18N, contributed many efforts towards the work from the beginning of APNG-CC. The authors also wish to thank the following people who contributed in many ways towards this draft. Martin J Duerst Yuan Jiang Kenichi Handa Stephen G Simpson Zhang Ling Zhu Bin Nelson Chin Lu Chin Ding ZyKaan Zhang ZhouCai Feng Hui Chen Shuyi Lua Kim Teng Victor Cheng Ken Lunde <<< More names ?? >>> Security Considerations Security issues are not discussed in this memo. Authors' Addresses Zhu,Hai-feng (HF. Zhu) Dept. of Computer Science & Technology Tsinghua University Beijing, 100084 China Tel: +86-1-2561144 ext. 3492 Fax: +86-1-2564173 Email: zhf@net.edu.cn Hu,Dao-yuan (DY. Hu) Tsinghua Networking Center Tsinghua University Beijing, 100084 China Tel: +86-1-2594016 Fax: +86-1-2564173 Email: hdy@tsinghua.edu.cn Wang,Zhi-guan (ZG. Wang) SC2 Division <> China Information Technology Standardization Technical Committee (CITS) Beijing, 100083 China Tel: +86-1-4012392 Fax: +86-1-4010601 Kao,Tien-cheu (TC. Kao) I.T. Promotion Division Institute for Information Industry(III) Taipei Taiwan Tel: +886-2-5631688 Fax: +886-2-563-4209 Email: tckao@iiidns.iii.org.tw Chang,Wen-chung (WC. Chang) Institute for Information Industry(III) Taipei Taiwan Tel: +886-2-7327771 Fax: +886-2-7370188 Email: chung@iiidns.iii.org.tw Mark R. Crispin Networks and Distributed Computing University of Washington 4545 15th Avenue NE Seattle, WA 98105-4527 USA Tel: +1 (206) 543-5762 Fax: +1 (206) 685-4045 Email: MRC@CAC.Washington.EDU