INTERNET-DRAFT EXPIRES: SEPT 1997 INTERNET-DRAFT Network Working Group J. P. Kim Internet Draft S. H. Choi Updates : 1557 I. S.Choi Category : Informational S. J. Park S. W. Chi Nat'l Computerization Agency December 1996 Update of Korean 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-abstract.txt" listing contained in the Internet-Drafts Shadow Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe), munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or ftp.isi.edu (US West Coast). Abstract Since RFC 1557, which is a Korean character encoding for internet messages, was distributed in 1993, most mailers have been implemented using it. However, it's been reported many occurrences of incompatible transfer of Korean mail messages such as broken mail messages. Therefore certain features are need to be extended, and ambiguous contents must be clarified. This document updates RFC 1557 to resolve above matters. This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Introduction This document updates the processing method being used to represent Korean characters in Internet messages defined by RFC 1557. It can be used in encoding or decoding Korean Character in 7bit mail messages only. This document also describes the encoding method for including multipart message and mail header with Korean characters. Other text subtypes, rich text and similar forms of text, are beyond the scope of this document. Processing of Multipart message with Korean characters According to RFC 1521, it confines available scope to each part in the Multipart message. That is, in the case of Korean message, the header and body encoding of each part must be redefined. Encoding for mail header with Korean characters In the case of mail headers with Korean characters, it is possible to encode entire header or only Korean characters. However a single token such as file name should be encoded as a whole. Application of KS C 5601 KS C 5601 noted in RFC 1557 is confined to only Wanseong code as specified in KS C 5601-1987 and KS C 5601-1989. Kim, S. H. Choi & I. S. Choi [Page 1] Internet Draft Korean Message Processing December 1996 Correction of RFC 1557 Because there is a missing ")" in 40th line of 2nd page of RFC 1557, it must be corrected as following : segment = SO 1*(one-of-94 one-of-94 SI ; ( Octal, Decimal.) --> segment = SO 1*(one-of-94 one-of-94) SI ; ( Octal, Decimal.) Examples * Hex digits in [ ] in the examples represent 2 byte Korean characters 1. Processing of Multipart message with Korean characters Content-Type: multipart/mixed; boundary="MAIL-boundary" This is a multipart message in MIME format. --MAIL-boundary Content-Type: text/plain; charset=iso-2022-kr Content-Transfer-Encoding: 7bit $)C@L0M@: C9 9xB0 :;9.@T4O4Y. ...... (skip) --MAIL-boundary Content-Type: text/plain; charset=iso-2022-kr Content-Transfer-Encoding: 7bit $)C@L0M@: 5N 9xB0 :;9.@T4O4Y. ...... (skip) --MAIL-boundary Content-Type: image/gif Content-Transfer-Encoding: Base64 Content-Disposition: attachment; filename="test.gif" ...... (skip) --MAIL-boundary-- 2. Encoding for mail header with Korean characters 1) Subject: [C7D1B1DBC0CC20B5E9BEEEC0D6B4C220C6EDC1F6] Subject: =?EUC-KR?B?x9Gx28DMILXpvu7A1rTCIMbtwfY=?= Subject: =?EUC-KR?B?x9Gx28DMIA==?= =?EUC-KR?B?tem+7sDWtMIg?= =?EUC-KR?B?xu3B9g==?= 2) Subject: Internet [C6EDC1F6B8A620BAB8B3C0B4CFB4D9] Subject: =?EUC-KR?B?SW50ZXJuZXQgxu3B9rimILq4s8C0z7TZ?= Subject: Internet =?EUC-KR?B?xu3B9rimILq4s8C0z7TZ?= Kim, S. H. Choi & I. S. Choi [Page 2] Internet Draft Korean Message Processing December 1996 3) Subject: Internet[C0B8B7CE20C6EDC1F6B8A6] Subject: =?EUC-KR?B?SW50ZXJuZXTAuLfOIMbtwfa4pg==?= 4) Subject: [B4E7BDC5C0C720452D6D61696C20C1D6BCD2B8A620] [BECBB7C1C1D6BDCABDC3BFC0] Subject: =?EUC-KR?B?tOe9xcDHIEUtbWFpbCDB1rzS?= =?EUC-KR?B?uKYgvsu3wcHWvcq9w7/A?= Subject: =?EUC-KR?B?tOe9xcDH?= E-mail =?EUC-KR?B?wda80rimIL7Lt8HB1r3KvcO/wA==?= 5) Subject: [BBE7BFEBC1DFC0CE204F53] [C8AFB0E6C0BB20B1E2C1D8C0B8B7CE] Content-Disposition: attachment; filename="[B9AEBCAD3030312E747874]" Subject: =?EUC-KR?B?u+e/68HfwM4gT1PIr7DmwLsg?= =?EUC-KR?B?seLB2MC4t84uLi4=?= Content-Disposition: attachment; filename="=?EUC-KR?B?ua68rTAwMS50eHQ=?=" References [ASCII] American National Standards Institute, "Coded character set -- 7-bit American national standard code for information interchange", ANSI X3.4-1968 [ISO2022] International Organization for Standardization (ISO), "Information processing -- ISO 7-bit and 8-bit coded character sets -- Code extension techniques", International Standard, 1986, Ref. No. ISO 2022-1986 (E). [KSC5601] Korea Industrial Standards Association, "Code for Information Interchange (Hangul and Hanja)," Korean Industrial Standard, 1987, Ref. No. KS C 5601-1987. [EUC-KR] Korea Industrial Standards Association, "Hangul Unix Environment," Korean Industrial Standard, 1992, Ref. No. KS C 5861-1992. [RFC822] Crocker, D., "Standard for the Format of ARPA Internet Text Messages", STD 11, RFC 822, UDEL, August 1982. [MIME1] Borenstein, N., and N. Freed, "MIME (Multipurpose Internet Mail Extensions): Part One: Mechanisms for Specifying and Describing the Format of Internet Message Bodies", RFC 1521, Bellcore, Innosoft, September 1993. [MIME2] Moore, K., "MIME (Multipurpose Internet Mail Extensions) Part Two: Message Header Extensions for Non-ASCII Text", RFC 1522, University of Tennessee, September 1993. Security Considerations Security issues are not discussed in this memo. Kim, S. H. Choi & I. S. Choi [Page 3] Internet Draft Korean Message Processing December 1996 Acknowledgments The authors wish to thank all the people who assisted in writing this document. We especially thank all the members of Internet Hangul Working Group coordinated by National Computerization Agency and the concerned in the han.comp.hangul and han.comp.mail newsgroup who provided valuable comments. Author's Addresses Jongpyo Kim National Computerization Agency Information Technology Research Division Yong-In, 449-840, Republic of Korea Phone : +82-331-260-2558 Fax : +82-331-262-2752 EMail : jpkim@nca.or.kr Seungho Choi Hangul & Computer Co., Ltd Division of Communications Seoul, 150-037, Republic of Korea Phone : +82-2-639-8315 Fax : +82-2-631-3757 EMail : sanjose@hnc.co.kr Insook Choi Microsoft Seoul, 135-777, Republic of Korea Phone : +82-2-531-4747 Fax : +82-2-531-4563 EMail : ischoi@microsoft.com Sungjae Park Hyundai Information Technology Aminet Development Department Seoul, 110-052, Republic of Korea Phone : +82-2-398-4728 Fax : +82-2-398-4683 EMail : Eureka@aminet.co.kr Songwon Chi Daou Technology, Inc Netscape Team Seoul, 135-080, Republic of Korea Phone : +82-2-3450-4676 Fax : +82-2-558-2907 EMail : swchi@daou.co.kr INTERNET-DRAFT EXPIRES SEPTEMBER 1997 INTERNET-DRAFT