Character Sets ISO-10646 and ISO-10646-J-1 (RFC1815)
Original Publication Date: 1995-Jul-01
Included in the Prior Art Database: 2000-Sep-13
Internet Society Requests For Comment (RFCs)
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.
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.
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.
This memo describes two text encoding schemes based on ISO 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...