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Character Sets ISO-10646 and ISO-10646-J-1 (RFC1815)

IP.com Disclosure Number: IPCOM000004072D
Original Publication Date: 1995-Jul-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 7 page(s) / 11K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

M. Ohta: AUTHOR

Abstract

Though the ISO character set standard of ISO 10646 is specified reasonably well about European characters, it is not so useful in an fully internationalized environment.

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 27% of the total text.

Network Working Group M. Ohta

Request For Comments: 1815 Tokyo Institute of Technology

Category: Informational July 1995

Character Sets ISO-10646 and ISO-10646-J-1

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.

Abstract

Though the ISO character set standard of ISO 10646 is specified

reasonably well about European characters, it is not so useful in an

fully internationalized environment.

For the practical use of ISO 10646, a lot of external profiling such

as restriction of characters, restriction of combination of

characters and addition of language information is necessary.

This memo provides information on such profiling, along with charset

names to each profiled instance.

Though all the effort is done to make the resulting charset as useful

10646 based charset as possible, the result is not so good. So, the

charsets defined in this memo are only for reference purpose and its

use for practical purpose is strongly discouraged.

Introduction

This memo describes two text encoding schemes based on ISO 10646

[10646].

As ISO 10646 specifies too little about how text is visualized, to

practically use ISO 10646, it is necessary to restrict the standard

minimally and then add some amount of profiling information.

For ISO 2022 [ISO2022] based national standards, sufficient profiling

information is provided by national standardization bodies, but, for

ISO 10646, such a profiling is not yet provided.

As the profiling of ISO 10646 largely affects which character or

combination of characters could be properly displayed, changes of

profiling of ISO 10646 are as significant as additions of new

character sets of ISO 2022.

That is, it's impractical to support the entirety of ISO 10646 (new

restriction or profiling can always be added), so a client needs to

know whether some restriction or profiling is being used before it

can decide whether to display the body part. Thus, it is necessary to

provide multiple charset names to each variation of ISO 10646.

For example, in Japan with Japanese windows NT, only those Han

characters already supported by MS Kanji code (mostly equivalent to

JIS X 0208 [JISX0208]) can be displayed, because no other font

pattern is commonly provided.

The other problem of ISO 10646 for Han characters is that, to display

them in quality required for daily plain text processing in

China/Japan/Korea, it is necessary to add profiling information on

which one of Chinese/Japanese/Korean the text is using. It should be

noted that this feature makes multilingual mixed

Chinese/Japanese/Korean text with ISO 10646 impractical.

Also, just as [RFC1521] was unclear about how bi-directionality

should be supported with "ISO-8859-6" a...