The Chinese Character Code for Information Interchange (CCCII), developed in Taiwan in 1980, contains characters for use in China, Taiwan, and Japan. In somewhat modified form, it has been adopted for use in the United States as ANSI Z39.64-1989, also known as the East Asian Character Code (EACC) for bibliographic use. In 1981, Takahashi Tokutaro of Japan's National Diet Library proposed standardization of a character set for common use among East Asian countries.
The Unicode Han character set began with a project to create a Han character cross-reference database at Xerox in 1986. In 1988, a parallel effort began at Apple based on the Research Libraries Group's CJK Thesaurus, which is used to maintain EACC. The merger of the Apple and Xerox database led to the first draft of the Unicode Han character set in 1989. The Unicode Working Group proposed this set for inclusion in ISO 10646 at the September 1989.
The Unicode Han character set extended the bibliographic sets to guarantee complete coverage of industry and newer national standards. The unification criteria employed in this original Unicode Han character repertoire were based on rules used by JIS and on a set of Han character identity principle (rentong yuanze) being developed in China by experts working with the Association for a Common Chinese Code (ACCC).
1989 meeting in Beijing was the beginning of informal cooperation
between the Unicode Working Group and the ACCC to exchange information
on each group's proposals for Han unification. A second ad hoc meeting
on Han unification was held in Seoul in February 1990. Just at this
meeting, the Korean delegation proposed the establishment of a group
composed of the East Asian countries and other concerned organizations
to study a unified Han encoding. From this informal meeting emerged
the Chinese/Japanese/Korean Joint Research Group (CJK-JRG). And
then, the December 1990 draft of the Unicode Han character set differed
from the first draft in that is used the principle of KangXi radical-stroke
ordering of the characters.
In the meantime, China announced that it was about to complete its
own proposal for a Han Character Set, GB 13000. Concluding that
the two drafts were similar in content and philosophy, the Unicode
Consortium and the Center for Computer and Information Development
Research, Ministry of Machinery and Electronic Industry (CCID, China's
computer standards body) agreed to merge the two efforts into a
single proposal. As a result of the agreement to merge the Unicode
Standard and ISO 10646, the Unicode Consortium agreed to adopt the
unified Han character repertoire that was to be developed by the
The first CJK-JRG meeting, held in Tokyo in July 1991, recognized
that there was a compelling requirement for unification of the existing
CJK ideographic characters into one coherent coding standard. Two
basic decisions were made: to use GB 13000 as the basis for what
would be termed "The Unified Repertoire and Ordering", and to verify
the unification results base on rules.
On March 27,
1992, the CJK-JRG completed the Unified Repertoire and Ordering
(URO), Version 2.0. This repertoire was subsequently published both
by the Unicode Consortium in The Unicode Standard, Version 1.0.
Volume 2 and by ISO in ISO/IEC 10646-1:1993.
In October 1993, the CJK-JRG became a formal subgroup of ISO/IEC
JTC1/SC2/WG2 and was renamed the Ideograph Rapporteur Group (IRG).
The Unicode Consortium participates in this group as a liaison member
of ISO. The second meeting in Hanoi in February 1994, the IRG agreed
to include Vietnamese Chu Nom ideographs in a future version of
the URO and to add a fifth reference dictionary to the ordering
In 1998, the IRG completed the work on the first supplement to the
URO, the CJK Unified ideographs Extension A. This set of 6,582 characters
is culled from national and industrial standards and historical
literature and is encoded in The Unicode Standard, Version 3.0.
And then, It was published by ISO in ISO/IEC 10646-1:2000. Now,
the IRG is considering additional CJKV ideographs submitted by China,
Taiwan, Hong Kong, Japan, Korea, Singapore, and Vietnam as further
extensions to the ideographic character repertoire in this standard.