Subject: Info on EACC/ANSI Z39.64

From: "K. Smith-Yoshimura" <[email-masked]>
Date: Thu, 23 Dec 1993 13:39:06 PST

REPLY TO 11/24/93 13:35 FROM [email-masked] "susan lasovick"

To Susan Lasovick --

Belated answer to your query posted on CCNET-L on 11/24/93 (I'm a CCCNET-L
lurker, but have been so backlogged in e-mail, I just got to it.)

> Can anyone tell me which Asian language codesets ANSI Z39.64 defines?

ANSI Z39.64 (East Asian Character Code Set for Bibliographic Information
Interchange, aka "EACC") includes a unified "Han" set of Chinese characters
drawn from CCCII (all of vol.  1 (most of plane 21), more common characters in
vol.  2 (rest of plane 21 to plane 23) and the variant volumes (variants
linked to the layer one characters on planes 21-23), PLUS all the Chinese
characters in CB2312-80 JIS X0208, and KIPS (the precursor of KSC 5608) that
were not in CCCII.  Thus simplified and traditional Chinese characters, joyo
kanji forms and kokuji, plus some Korean variants are all included; kana from
JIS X0208 and hangul from KIPS.

EACC itself is an integration of all these sets; it follows the CCCII code
structure, and most of the character codes are the same as those in CCCII.
However, CCCII often encodes the same character more than once (depending on
semantic use); in these cases EACC usually encodes it only once, giving
preference to encoding a common variant as a variant rather than as an obscure
character.  (Favorite example is the three-stroke simplified character for
10,000; CCCII also encodes it as a layer-one character because it is also part
of a late-Han surname.  We use the layer-2 encoding.)  The published versions
of CCCII does not include Joyo kanji forms that are not also Chinese variant
forms, kokuji, kana, or hangul (although with the layer structure you could
simply specify a plane as an entire code-set.  However, that would mean even
more redundant encoding of Han characters.  EACC tried hard to follow the
principle, "one character, one code" for all Chinese characters, which was
revolutionary in its time.  Most of the EACC development focused on encoding
the Chinese characters in the non-CCCII sets so that they were linked to the
correct traditional (fanti) characters and making the correct mapping tables
between code sets.

RLG created an online "RLIN CJK Thesaurus" that shows the cross-mappings
between EACC and CCCII, GB, JIS, KIPS (and also one of the Chinese Telegraph
Codes).  Since the entire EACC repertoire has been included in Unicode/IS
10646 (plus all the Han characters added to published standards since EACC was
first developed in 1983), we will be relying on Unicode-EACC cross mapping
tables in the future, especially to export CJK bibliographic records with EACC
encoded characters to Unicode/10646 supported products.

Enjoy your postings by the way.  Now I'll go back to lurking. Happy holidays.

Karen Smith-Yoshimura
(N.B.  I'm RLG rep to the Unicode Consortium, X3L2, and frequently part of the
US delegation to ISO-IEC JTC1/SC2/WG2 [the folks who brought you IS 10646].
I co-authored the text for ANSI Z39.64 and wrote one of the position papers to
WG2 on Han unification.  After a decade worth of effort, it's gratifying to
see it pay off!)
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Karen Smith-Yoshimura                     [email-masked] [bitnet]
The Research Libraries Group              [email-masked] [internet]
1200 Villa Street                         Phone: 415-691-2270
Mountain View, CA  94041-1100             Fax: 415-964-0943

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