RFC 1554 (rfc1554) - Page 1 of 6

ISO-2022-JP-2: Multilingual Extension of ISO-2022-JP

Alternative Format: Original Text Document
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Network Working Group                                            M. Ohta
Request for Comments: 1554                 Tokyo Institute of Technology
Category: Informational                                         K. Handa
                                                                     ETL
                                                           December 1993


          ISO-2022-JP-2: Multilingual Extension of ISO-2022-JP

Status of this Memo

   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 memo describes a text encoding scheme: "ISO-2022-JP-2", which is
   used experimentally for electronic mail [RFC 822] and network news
   [RFC 1036] messages in several Japanese networks.  The encoding is a
   multilingual extension of "ISO-2022-JP", the existing encoding for
   Japanese [2022JP].  The encoding is supported by an Emacs based
   multilingual text editor: MULE [MULE].

   The name, "ISO-2022-JP-2", is intended to be used in the "charset"
   parameter field of MIME headers (see [MIME1] and [MIME2]).

Description

   The text with "ISO-2022-JP-2" starts in ASCII [ASCII], and switches
   to other character sets of ISO 2022 [ISO2022] through limited
   combinations of escape sequences.  All the characters are encoded
   with 7 bits only.

   At the beginning of text, the existence of an announcer sequence:
   "ESC 2/0 4/1 ESC 2/0 4/6 ESC 2/0 5/10" is (though omitted) assumed.
   Thus, characters of 94 character sets are designated to G0 and
   invoked as GL.  C1 control characters are represented with 7 bits.
   Characters of 96 character sets are designated to G2 and invoked with
   SS2 (single shift two, "ESC 4/14" or "ESC N").

   For example, the escape sequence "ESC 2/4 2/8 4/3" or "ESC $ ( C"
   indicates that the bytes following the escape sequence are Korean KSC
   characters, which are encoded in two bytes each.  The escape sequence
   "ESC 2/14 4/1" or "ESC . A" indicates that ISO 8859-1 is designated
   to G2. After the designation, the single shifted sequence "ESC 4/14
   4/1" or "ESC N A" is interpreted to represent a character "A with
   acute".



Ohta & Handa
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