About: ¡i CNS11643 National Chinese Standard Interchange Code
¡j ¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@ TOP
1. History
| ¡@In September
1980, the Science and Technology Information Center
(STIC) of Executive Yuan gathered local encoding specialists
and academics to attend a conference in Shi-Tou. The
preliminary encoding principles were determined and
reported to the Executive Yuan for assessment as the
Encoding Principles of National Chinese Information
Standard Interchange Code. On September 2, 1981, the
Executive Yuan sent an official memorandum to the
STIC requesting the Center to invite the Ministry
of Education (MOE), the Bureau of Standards and Metrology
and Inspection (NBSMI) and the Electronic Data Processing
Center Directorate, General of Budget, Accounting
and Statistics, Executive Yuan (EDPC) to form a project
working team and aggressively pursue encoding of Chinese
characters. In July 1982, a single set of frequently
used glyphs was encoded but the number of characters
collected was inadequate. On May 9, 1983, the National
Information and Communication Initiative (NICI) of
Executive Yuan once again confirmed and set the encoding
methodology and formed an encoding technical working
group on May 12. The group aimed at discussing and
studying the finer rules of the existing encoding
principles. At the end of October, "Chinese Ideographic
Standard Code for Information Interchange" (CISCII)
was completed and it was resolved to trial the code
for two years. Upon expiration of the trial period,
the STIC and the EDPC invited various concerned organizations
and enterprises to form a technical team. Subsequent
to the team's review on trial results and amendments
made to the encoding standards, in March 1986, the
code was formally assessed and announced for implementation
by the Executive Yuan. In August 1986, the code was
announced to be the National Standard Code by the
NBSI and was numbered CNS11643. In 1992, in response
to requirements of various users, the code was extended
from containing 2 character planes (13,051 glyphs)
to 7 character planes (48,027 glyphs). In May, it
was renamed the "Chinese Standard Interchange Code" |
2.
Intended Areas of Application:
¡@ This standard is applicable to the processing of Chinese
language information
3. Encoding Considerations:
| (1)
|
Restricted
to character sets included in the four tables of standard
characters announced by the MOE |
| (2)
|
Based on the
frequency and the extent of application, glyphs are
coded in each character plane to suit users of all
levels. |
| (3)
|
In
compliance with "CNS5205 Information processing: 7-Bit
Coded Character Set For Information Interchange" used
for international information transmission & the standards
of "CNS7654 Information processing: ISO 7-bit and
8-bit coded character sets - Code extension techniques". |
| (4) |
Include frequently
used foreign language alphabets and glyphs used by
industries, businesses and educational institutions. |
4. Principles of Structuring Character
Sets
| (1)
|
"Chinese
Standard Interchange Code" provides 16 character planes.
Each plane is divided into 94 rows and each row has
94 columns. Altogether, a total number of 8,836 glyphs
can be accommodated in each plane. Character planes
1 to 11 are for standard Chinese characters while
character planes 12 to 16 are user-defined areas,
allowing users to define glyphs that are yet to be
collected in the standard areas. |
| (2)
|
The character
set in each character plane is generally coded in
the order of usage frequency. Character plane one
is mainly for frequently used characters. Character
plane two is for less frequently used characters.
Character plane three is for rarely used characters
and frequently used Chinese character variants. Character
plane four is mainly used for Chinese ideographs of
ISO DIS 10646 2nd edition, characters used in respective
organization, Information Technology enterprises and
the Residency System. Character plane five is for
rarely used characters and character plane six and
seven are mainly for Chinese character variants. Ideographs
defined in character planes one and two were announced
national standards on August 4, 1986. |
5.
Principles of structuring character codes
| (1)
|
Characters
and fonts were selected based on the "Table of Standard
Chinese Characters" published by the MOE.
Description :
There are mainly two hassles associated with the use
of Chinese characters. One is that there are a large
number of characters and the other is that the number
of Chinese character variants is increasing. Currently,
the total number of Chinese characters is large but
in fact, those frequently used by people are around
5,000 characters only. New words continue to increase,
thus making the processing of Chinese language information
a hassle. The Table of Standard Character Sets published
by the MOE is the work of many years in terms of collection,
assessment, analysis and selection. It is an unbiased
and objective source of ideographs currently in use
and it suits the requirements of general users.
|
| (2)
|
ach
Chinese character is represented by a two-byte code,
which is represented by hexadecimal characters and
numbers.
Description :
The use of a 2-byte encoding unit will increase processing
efficiency and the speed of information transmission
also becomes faster. These features meet the requirements
of general data processing. Hexadecimal encoding is
used as data processors are accustomed to this numbering
method and it is the simplest way to represent a 2-byte
unit.
|
| (3) |
Comply
with the standards of Information Interchange CNS
5205 and CNS 7654.
Description :
This encoding meets the requirements of the standards
of information interchange CNS5205 and CNS7654. All
control codes are avoided, which are "00" to "20"
and "7F" of the code set. A 7-bit code set has 94
code positions and a 2-byte code allows coding for
8,836 characters, to form one character plane.
|
| (4)
|
Characters
are defined in each character plane in the order of
usage frequency
Description :
At the time of transmitting information, if the characters
to be transmitted appeared in different character
planes, the control codes used to switch character
planes must be sent out first. In order to increase
transmission efficiency, words that commonly appear
together are defined in the same character plane to
reduce the number of times having to switch between
character planes.
|
| (5) |
Encoding
in the order of Total Stroke Count and Radicals.
Description :
Each character plane is coded in the order of total
stroke count, then radicals and lastly, stroke order.
Users are only required to input the actual total
stroke count of the character to find out the national
standard code. |
6.
Description of Character Sets:
| (1)
|
Standard
Areas |
|
Plane One
:
In order to reduce the number of times required to
convert character planes, most frequently used symbols,
alphabets and radicals of Chinese characters are coded
in character plane one. Coded characters and code
areas are as follows: |
|
1.
Symbol Area
The encoding area for symbols is planned at address
2121 to 427E of character plane one. The area comprises
a total of 3,102 code positions. Currently, the 684
temporarily coded symbols are listed below :
(1) 1 x tab
(2) 28 x punctuation marks
(3) 89 x brackets and tabulation symbols
(4) 34 x general symbols
(5) 51 x academic symbols
(6) 31 x unit symbols
(7) 42 numerical symbols including 10 Arabic numerals,
20 Roman numerals and 12 Chinese numerals
(8) 100 foreign alphabets including 26 Capital English
Alphabets, 26 Small English Alphabets, 24 Capital
Greek Alphabets and 24 small Greek Alphabets.
(9) 42 Chinese Phonetic Alphabets
(10) 20 numerical order symbols
(11) 213 Chinese character radicals
(12) 33 control code symbols
2. Chinese Character Area
Character Plane One :
Coding interval from 4421 to 7D4B is encoded with
5,401 Chinese characters. Other than sourcing the
4,808 characters from the "Table of frequently used
standard Chinese characters" published by the MOE,
587 characters and 6 variants frequently used in High
School and Primary School textbooks are also coded.
Character Plane Two :
Coding interval from 2121 to 7244 is encoded with
7,650 Chinese characters. The character set includes
6,330 characters sourced from the "Table of less frequently
used standard Chinese characters" published by the
MOE and 1,320 more frequently used characters sourced
from the MOE's "Table of rarely used standard Chinese
characters"
Character Plane Three :
Coding interval from 2121 to 6246 is encoded with
6,148 Chinese characters. The character set is sourced
from the first section of user-defined character plane
14, which was temporarily coded by the EDPC, Executive
Yuan in June 1988.
Character Plane Four :
Coding interval from 2121 to 6E5C is encoded with
7,298 Chinese characters. The character set includes
(1) 171 characters from the last section of user-defined
character plane 14, which was temporarily coded by
the EDPC, Executive Yuan in June 1988; (2) 7127 characters
used in the Residency system and other organizations,
ISO 10646 Chinese Ideographs Character Set, version
2 and frequently used characters in Information Technology
enterprises.
Character Plane Five :
Coding interval from 2121 to 7C51 is encoded with
8,603 Chinese characters. The character set is sourced
from the "Table of rarely used characters" published
by the MOE, which have not been included in the previous
four character planes.
Character Plane Six :
Coding interval from 2121 to 647A is encoded with
6,388 Chinese characters. The character set includes
characters that have not been included in the previous
five character planes and the Chinese character variants
published by the MOE which are under (include) 14
strokes.
Character Plane Seven :
The coding interval from 2121 to 6655 is encoded with
6,539 Chinese Characters. The character set includes
characters that have not been included in the previous
six character planes and the Chinese character variants
published by MOE which are under (include) 15 strokes.
|
|
|
|
| (2) |
User-defined
Areas |
|
To cater
for different types of Chinese information processing,
CNS11643 has reserved character plane 12 to 15 for
user-defined characters. Chinese characters or symbols
that have yet to be classified as national standard
characters are coded in this area based on user requirements.
p to 48,027 Chinese characters are encoded in the
amended and extended version of CN11643. The code
has covered characters as defined in the four "Table
of Standard Chinese Characters" namely in the categories
of frequently used, less frequently used, rarely used
and Chinese character variants. However, since the
implementation of the on-line computerized Residency
Information System, the characters used to construct
the national population database have exceeded the
national standard characters by some 30,000 characters
used for names. To enable data transmission and interchange
for this type of character codes, the EDPC, Executive
Yuan temporarily defined the interchange codes in
user-defined areas: Character Plane 15: Coding interval
from 2121 to 6D39 is encoded with 6,831 Chinese characters.
Ideographs are sourced from the 15th character plane
of the Residency Information System. EUC codes are
used in the Residency Information System and the encoding
principles of EUC codes are identical to those of
CNS11643. For easier understanding, existing ideographs
and definitions are used. However, amongst the 7,167
characters defined in character plane 15 of the Residency
Information System, there are 2 self-repeating characters
and 336 repeated characters that were already included
in the first 7 CNS character planes. To avoid the
situation of "one word, two codes", repeated parts
are deleted to save the Household Registration and
Military Service departments from having to repetitively
convert codes; the spaces originally occupied by repeated
characters are left blank after deletion. |
7.
Application of CNS11643
| (1)
|
Designation
of Character plane |
|
In accordance
with the regulations in Chapter 5.3.9 of CNS654
(July 15, 1989 edition), Chinese character codes
can be placed in Multiple Byte Graphic Repertoire
and designated to character set G1 by 4-byte escape
order codes of ESC 2/4 2/9 F or designated to character
set G3 by ESC 2/4 2/11 F. F can be used to designate
the corresponding character planes from 1 to 16
by 3/0 - 3/15. As for English character sets, they
can be designated to character plane G0 via ESC
2/8 F under the 7-byte environment. Currently, ending
characters of CNS11643 character planes 1 to 7 are
officially registered by the International Organization
for Standardization (ISO) as 4/7 to 4/13 and can
also be used in character set designation. Existing
ending characters of CNS11643 character planes and
ISO ending characters are cross-referred below:
|
CNS
Character Plane
|
CNS
Ending Character
|
ISO
Ending Character
|
|
Character
Plane 1
|
3/0
|
4/7
|
|
Character
Plane 2
|
3/1
|
4/8
|
|
Character
Plane 3
|
3/2
|
4/9
|
|
Character
Plane 4
|
3/3
|
4/10
|
|
Character
Plane 5
|
3/4
|
4/11
|
|
Character
Plane 6
|
3/5
|
4/12
|
|
Character
Plane 7
|
3/6
|
4/13
|
|
| (2) |
Character
Plane Switching |
|
1.
Use G0 character plane by SI, Lock method.
2. Use G1 character plane by SO, Lock method.
3. Use G2 character plane by LS2, Lock method.
4. Use G3 character plane by LS3, Lock method.
5. Use G2 character plane by SS2, Non-lock method.
6. Use G3 character plane by SS3, Non-lock-in method.
For convenience, when the terminal facilities are
turned on, the three character sets G0, G1, G2 can
be set as ASCII, character plane one and character
plane two respectively, and character set G3 can be
set as other frequently used character plane Note:
Please refer to CNS7654 for further user details of
the above control codes. |
8.
Promoting the application of CNS11643
The CNS11643
coding system complies with regulations of national
standards. The Bureau of Standards, Metrology and
Inspection, Ministry of Economic Affairs (originally
the Central Bureau of Standards) is responsible for
review and amendment. In order to strengthen the promotion
on the application of the standard, the Bureau has
passed on the system and Chinese character files to
EDPC of Executive Yuan to manage and promote the Standard.
To preserve the completeness of the Chinese character
files of this system for the promotion of this national
standard, the EDPC has obtained the agreement of both
the Ministry of Interior and the Industrial Development
Bureau, MOEA, to provide the character files for public
use free of charge. Current status of CNS11643 application
is as follows:
|
| (1)
|
Domestic
Application |
|
1.
CNS11643 has been incorporated into the "Mutual regulations
for information processing in governmental organizations",
which is also the standards for the Chinese language
processing system that most foreign Information Technology
firms comply with.
2. Standard transmission codes for the exchange of
electronic memorandums in governmental organizations:
All governmental organizations of the Executive Yuan
must covert the electronically transmitted memorandums
into CNS11643 codes so long as the memorandums are
transmitted via the "exchange center" (established
in the Information Management Center, Ministry of
Transportation).
3. Application of large-scale information system domestically:
The representative example and the most important
of all systems is the national Residency Information
System. At the moment, the national on-line Residency
Information System is built under the MITUX operating
system, which is a type Client/ Server architecture.
Its internal codes are ECU codes used in the UNIX
operating system. Although EUC codes are different
in length to that of CNS11643 codes, EUC codes use
the CNS 11643 encoding architecture and character
sets. Hence, this can be regarded as an example of
applying CNS11643 codes as internal codes.
4. The Big-5E character set (extended Big-5 code)
promoted by the Research Development and Evaluation
Commission (RDEC), Executive Yuan also uses CNS11643
as its blueprint. The Big-5E character set collects
3 radical characters from CNS character plane 1, 3,891
characters from CNS character plane 3 and 59 frequently
used Chinese characters in documents that are defined
in CNS character plane
5. Foreign Information Technology enterprises have
provided the interchange formula for conversion between
the internal codes and CNS11643 code as well as calling
tools to assist users in the exchange Chinese language
information.
|
| (2)
|
Foreign
Application |
|
ISO10646
and Unicode currently collect 26,783 Chinese ideographs
amongst which 22,892 characters were sourced from
CNS11643. They are made up by 6,307 characters from
CNS11643 character planes 1,2,3, 2,965 characters
from character plane 4, 395 characters from character
plane 5, 196 characters from character plane 6, 133
characters from character plane 7 and 86 characters
from character plane 15. The fact that our national
standards are compatible with international standards,
is not only going to provide domestic computer manufacturers
with a competitive edge in the international market,
but in future, when ISO10646 and Unicode are fully
developed, Chinese character codes used currently
can also be successfully interchanged. |
About¡G ¡iBig-5E Code¡j
¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@ TOP
1.
History
| The
EDPC, Executive Yuan was appointed to assist with
the problem experienced by many governmental organizations
using the Big-5 Code that user-defined characters
in electronically transmitted memorandums cannot be
successfully interchanged. After several meetings
of discussion, it was resolved to appoint the RDEC,
Executive Yuan to set up the project "Big-5 Code Extension",
to be implemented by the Chinese Foundation for Digital
Technology (CMEX). In July 1997, the extension was
complete and Big-5 Plus Code came into existence.
However, most manufacturers have not adopted the result
of this project hence related user products were unavailable.
Nevertheless, the "standard character sets" completed
as part of the extension plan contained the most frequently
used user-defined characters in governmental documents
and if applied in the user-defined area of the Big-5
Code, user-defined characters frequently used can
be consolidated thus reducing the frequency of code
conversion. Bearing this in mind, the RDEC, Executive
Yuan once again appointed the Chinese Foundation for
Digital Technology to select 3,954 characters from
Big-5E and constructed the"Big-5 Extension Character
Set in user-defined areas of the Big-5 Code; in line
with the "e-Government Project" of the Executive Yuan,
Big-5E was set as one of the codes with the ability
to process Chinese characters in the exchanging of
electronic official memorandums. |
2.
Encoding Principles of Big-5 Plus
| (1)
|
Length
is kept at double byte. That is the first bit of high
byte. (MSB=1) |
| (2)
|
Preserve
the existing architecture of "Standard character areas"
and "User-defined areas" to allow for compatibility
of existing systems. |
| (3)
|
Source
characters from CNS11643 and ISO10646 Chinese Ideographs
Character Sets and use the encoding logic of CNS11643. |
| (4) |
Incorporate
the character sets of ISO646 or CNS 11634 and widely
used Yi-Tian user-defined characters and symbols as
part of the "Standard Character Set" and keep the
existing code positions. |
| (5) |
Any
radical that is also a character by itself (such as
Jien, Mu, Shuei, Huo, Tu) is not encoded again. |
| (6) |
The
latter character of a repeated character is deleted
and incorrect characters are rectified in accordance
with CNS11643. |
3. Source of the character
set
| (1) |
Source
of Big-5 plus characters |
|
The
internally defined character sets of Big-5 are identical
to that of CNS11643 character planes 1 and 2. Thus,
Big-5 Plus codes completed in July 1997 as part of
the extension project also used CNS11643 as the blueprint
with "standard character set" and "recommended character
set" being completed. The 4,670 glyphs in the "standard
character set" are frequently used Chinese characters
in normal documents. Of the 4,670 glyphs, 4,145 characters
were included in the CNS11643 character plane 3 and
219 characters were included in character plane 4.
The 3,250 glyphs in the "recommended character set"
are frequently used characters collected by manufacturers. |
| (2) |
Source
of Big-5E characters |
|
Big-5E
characters are mainly sourced from the Big-5 Plus
character set. Due to the fact that there is limited
space in user-defined area of the Big-5 code, the
Big-5 Plus character set cannot be fully incorporated.
Hence, the selection is limited to only 3,954 characters
appearing in the CNS11643 character set and the ISO10646
Chinese Ideographs Character Sets that are also frequently
used by governmental organizations. |
4. Code Architecture
| (1) |
Encoding
Interval of Big-5 Plus |
|
Big-5 originally
contains a total of 19,782 code positions. The 19,872
code positions contained in Big-5 Plus were extended
to 23,940 positions (high byte: 81-FE, low byte: 40-7E,
80-FE). Description of the Big-5 Plus character set
is as follows: |
|
1.
Standard Character Set 1: This area is the existing
the Big-5 standard character area with two repeated
characters deleted and the coding interval is from
A140 to F9FE (high byte- A1-F9, low byte- 40-7E, A1-FE).
A total of 13,973 glyphs are collected including 5,401
frequently used Chinese characters (A440-C67E), 7,693
less frequently used Chinese characters (C940-F9D5),
471 symbols (A140-A3FE) and 408 glyphs (C6A1-C8FE) |
|
2.
Standard Character Set 2: This area is the extended
part; coding interval is from 8180 to FEA0 (high byte:
81-F9, low byte:0-A0) and a total of 4,158 Chinese
characters are coded. |
|
3.
CMEX Recommended Character Set: Due to limited code
space in the Big-5 system, 3,454 characters including
frequently used rare characters, Chinese character
variants, simplified Chinese characters and Japanese/Korean
Han characters in the first and second standard character
sets cannot be incorporated. It was recommended by
the CMEX to collect these 3,454 characters in this
area. The coding intervals are located in the existing
user-defined area from 8140 to 83FE and from 8E40
to A0FE (high byte: 81-83, 8E-A0. low byte: 40-7E,
A1-FE). |
|
4.
User-defined area: If only the first and second standard
character sets are used, there are 5,809 available
user-defined code spaces. However, if the recommended
character set is used at the same time, the user-defined
area only has 2,355 available code spaces as the Big-5
Plus recommended character set occupies the coding
intervals from 8140 to 83FE and from 8E40 to A0FE.
The available coding intervals are from FA40 to FEFE
(785code spaces) and from 8440 to 8DFE (1,570 code
spaces). |
| (2) |
Coding
Interval of Big-5E |
|
1.
8E40 - 8E42 : Coded 3 radicals from the CNS11643 character
plane 1 (Defined in Yi-Tien: C6C2, C6C5, C6C6) |
|
2.
8E43 - A0FE : Coded 2,980 Chinese characters from
CNS11643 character plane 3. |
|
3.
8140 - 86DF : Coded 911 Chinese characters from CNS11643
character plane 3. |
|
4.
86E0 - 875B : Coded 59 Chinese characters from CNS11643
character plane 4. |
|
5.
875C - 875C : Chinese character of "zero" |
|
6.
875D - 87EE : 128 Reserved code spaces |
|
Installation
tools and data files of Big-5E Code are available
from the RDEC website. The public is welcome to access
them via the RDEC web address¡Gwww.rdec.gov.tw/big-5e/bigindex1.jsp |
About : ¡iEUC
code (Extended UNIX Code)¡j ¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@
TOP
1. Code Architecture
¡D(Extend Unix Code¡AEUC)Internal codes used by the UNIX operating
system
¡DCode length is 4 bytes.
2. Current Status of Application
¡DUsed by Household Registration and Military Service
Organizations : The length of the EUC code is 4 bytes.
Thus, it is able to collect characters used for up to
70 or 80 thousand names and meets the requirements of
national household registrations.
3. Relationship with CNS11643
¡DAlthough the length of this code is different to that
of CNS11643, the code however adopts the coding architecture
and the character set of CNS11643.
¡DCorrespond to CNS11643: eg. CNS 12121 = EUC 8EA1A1A1h
(h represents hexadecimal)
¡@¡E1st
byte : 8Eh (Fixed value)
¡@¡E2nd byte : A0h + CNS character plane (eg.: the third
character plane is A3h)
¡@¡E3rd byte : 80h + CNS high byte
¡@¡E4th
byte : 80h + CNS low byte
¡DIt
is not required to cross-refer codes one by one when converting
EUC codes into CNS11643 codes. The only requirement is
to obtain the CNS character plane number ( eg "3" of A3h)
in the 2nd byte of EUC codes and then re-set the high
bit of the 3rd byte and 4th byte of the EUC codes to "0"
(off) to cancel the Chinese and English identification
code.
About : ¡i
Chinese Character Code for Information Interchange (CCCII)¡j
¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@
TOP
1.
History
In 1979, due to USA's urgent requirement to process some data
in East Asian language by computers, a conference was held
at Standard University, California to plan for an automated
East Asian Library and to set a standard for Chinese Interchange
Code as the basis of automation. In our country at the time,
a suitable set of code was not available and Japan was the
only nation that provided the national standard JISC6226
code. Hence, in the absence of other standards, the USA
adopted the Japanese standard. However, the number and shape
of Japanese Kanji differ significantly from those of Chinese
characters and are inadequate to represent Chinese characters.
In addition, this act has also significantly impacted the
survival of the Chinese culture in the computerized era.
Hence, representatives from our nation and the Chinese American
East Asian Library opposed strongly to this idea. Subsequent
to heated debates, the proposal raised by Japan and the
USA was temporarily negated. At the same time, our representatives
also promised to put forward a set of Chinese interchange
code to compare with JISC6226 in the annual meeting of the
Asian Study Association in March the next year.
After returning to Taiwan, the representatives reported
the issue to Mr. Kuo-Ding Lee- Minister Without Portfolio,
the National Science Council and the Chinese American Association.
These organizations gathered a group of local Character
Study specialists, Library specialists and computing experts
to form the "Chinese Character Analysis Group" (CCAG) and
started the work of sorting out our national characters
as well as resolving technical problems encountered in the
processing of Chinese language data by computers. Professor
Chieng-Jyuen Hsieh led the CCAG, assisted by Professor Chung-Tao
Chang. Other project participants included Professors Chien-Hao
Wang, Ding-Chung Chang, Jyuen-Fu Jou, Chung-Kuei Pan, Ho
Jou, Jian-Chiau Yang and Ke-Dong Huang.
In the next annual meeting of the Asian Study Association,
our country proposed the "Chinese Character Code for Information
Interchange" (CCCII) containing a total of 4,808 characters.
The architecture of CCCII was accepted but the USA requested
us to extend the character set. The CCAG finished compiling
the second character set in 1981, which included 17,032
Complex characters and 11,517 variants. (Refer to Volume
2 of Version 2, published in 1982, and Volume 2 of Version
3, published in 1985 for details). In 1987, the third character
set was completed and published, including 20,583 Complex
characters. Other than extending coding for 53,940 characters
on the two occasions, the 64 x 64 and 32 x 32 machine-readable
scripts were also completed. Besides, for convenient word
processing on computers, the "Chinese Character Database"
(CCDB) was also compiled, in which radicals, strokes and
pronunciation of each word and all types of corresponding
codes and input codes were listed.
2. Character Coding Principles
(1) Collected characters must be recognized by Character Study
academics.
(2) Encoded in the order of radicals and stroke order.
(3) Using the code point to represent the relationship
between Complex Chinese characters and variants: For example,
Simplified Chinese characters are treated as variants by
CCCII. The encoding value of Simplified Chinese characters
in the first byte exceeds that of Complex Chinese characters
by six, but the encoding value of these two characters in
the 2nd and 3rd byte are identical. A relationship can also
be established between other variants and Complex Chinese
characters in terms of code points- that is, the encoding
value of variants in the first byte exceeds that of Complex
Chinese characters by multiples of six. This is because
Complex Chinese characters occupy six character planes (one
character plane consists of 94 x 94 code points); variants
are placed in the subsequent character planes and are related
to the corresponding Complex Chinese characters as described
above.
3. Code Architecture
¡DThe CCCII is a more special type of Chinese Character
Code, using 3 bytes to represent a Chinese character. Each
byte takes up 94 code positions; hence the code set is consist
of 830,534 code spaces in total.
4. Current Status of Application
¡DUsed by libraries domestically and overseas.
About : ¡iISO10646
and Unicode Chinese Ideographs Character Set¡j
¡@¡@¡@¡@¡@¡@¡@¡@¡@¡@ TOP
| |
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Due
to culture differences and the fact that the respective
countries use different characters for numerals, different
scripts and different character application styles,
ever since computers were used in the processing of
information, mankind faced the problem of interchanging
data between different countries. Although international
coding standards such as ISO 646 and ISO 2022 are
available as a guideline for the respective countries
to set their own internal code or national standard
interchange codes, which can be also be exchanged,
as mentioned previously, ESC control codes of different
length can increase the difficulties of data processing.
In addition, it is impossible and unnecessary for
each country to code other characters in their own
standard character sets. How can we process electronic
messages from other countries in the new century of
forever-changing Internet technology? |
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2. |
Process of defining ISO 10646 |
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In
order to resolve the difficulty of exchanging computer
data between different countries, from 1984, two organizations
emerged in the hope of developing a mutual encoding
character set. One was the SC2/WG3 working group of
Joint Technical Committee 1 (JTC1), an organization
jointed formed by the ISO and the International Electrotechnical
Commission (IEC). The working group proposed the draft
for ISO10646 with the intension of uniting universally
used character sets to form a master character set
to satisfy requirements of international information
exchange. The other organization was Unicode Consortium,
which also attempted to adopt new concepts and architecture
in the designing of Universal Code (abbreviated to
Unicode). The work and direction of these two organizations
started off in separate ways but eventually they were
combined to form the highly regarded standard at present,
ISO10646/Unicode which provides a mutual encoding
standard for the representation, transmission, interchange,
processing, storing, inputting and displaying of global
language characters. The standard not only avoided
the waste of resources, but it also met the ideal
of uniting the standards for global character interchange. |
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From
the time when the ISO/IEC JTC1/SC2/WG2 working group
was first established in 1986 to the time when the
first part of the ISO 10646 standard "Architecture
and Basic Multilingual Plane" was published, the development
phase of ISO 10646 has lasted for 10 years. The process
of development is summarized below: |
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1984.4
Set up of Working Group ISO/IEC JTC1/SC2/WG2
1987.3 Determine Encoding Architecture
1989.1 Published first Draft Proposal
1989.12 Published second Draft Proposal
1990.12 Published first Draft International Standard
1991.6 Passed a resolution in favor of 1st
1992.6 Passed a resolution in favor of 2nd DIS
1993.5 Published ISO10646-1 (Part 1)
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In
the first Recommendation Draft of ISO 10646, Version
1.0, the standard was named the Multiple Octet Coded
Character Set and it was explained that the encoding
architecture was in the four-octet format, making
up 128 Groups. Each Group contained 256 character
planes and each plane provided 256 x 256 code spaces.
The 32nd character plane of the 32nd group was the
Basic Multilingual Plane (abbreviated to BMP). In
the ISO 10646-1 version published in 1993, the standard
was named the Universal Multiple-Octet Coded Character
Set (abbreviated to UCS). BMP was defined in character
plane 0 of group 0. Upon application, if all required
character sets are in the BMP, only a two-octet encoding
architecture is required, otherwise a four-octet encoding
architecture is required. Combined use of these two
types of encoding architecture is not allowed. That
is, either a two-octet or a four-octet regular-length
encoding architecture is to be used; the purpose is
to avoid the pitfall of ISO 2022 of irregular-length
codes. |
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Given
this condition, representatives participating in the
setting of ISO 10646 standard were all trying their
best to lobby for the inclusion of their national
characters in the BMP; aiming to utilize the advantage
that BMP only takes up four-octet and to attain higher
processing efficiency by using a four-octet code than
that of a four-octet architecture. Although the BMP
was very important, its code spaces were limited.
Hence it is crucial at the time of setting the standard
to consider how to more effectively utilize these
code spaces in order to process more frequently used
ideographs. In the original design of the BMP, other
than Western Pin-Yin characters and symbols, only
Han character sets used in Japan, South Korea and
China were coded. No consideration was given to Taiwan's
character sets. Consequently, the government actively
organized a non-official organization under the name
of Taipei Computer Association (TCA) to participate
in the setting of ISO 10646 standard, lobbing for
inclusion of Complex Chinese characters in the BMP. |
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Basically,
all characters used in Taiwan, China, South Korea
and Japan are Han characters. Based on the encoding
concepts, these characters should not be coded separately
as it resulted in the situation of one character being
represented by multiple codes, which is contrary to
the fundamental principle of ISO 10646 of "one character,
one code". As a result, representatives from our country
and China proposed the Han Character Set (HCS), which
was supported by the USA and other representing countries.
The Character Set was developed progressively and
in the BMP of ISO 10646-1 announced in 1993, Han characters
used in Taiwan, China, Japan and South Korea were
consolidated to become the CJK Unified Ideographs
and were encoded. This was a satisfactory solution
for the major Asian countries that use Han characters.
The BMP character set will be introduced in later
paragraphs. |
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Since
ISO 10646-1 was published in 1993, although the BMP
had limited space left, many nations' characters have
yet to be incorporated into the plane. Ideographs
users such as our country and China have many Chinese
characters that have yet to be coded into this standard.
Hence, up until now, ISO 10646 is still being amended
and extended. However, in recent years, the close
cooperation of SC2/WG2 and Unicode Consortium has
sped up the pace of amendments. Up until now, close
to 30 amendments and documents of technical editing
were accumulated; it is indeed a stunning effort.
Based on WG2's estimation, it is expected that the
new version of ISO 10646 will be released in 2000.
The parallel Unicode Version 3.0 will possibly be
released first in the 4th quarter of 1999. |
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3. |
Overall
architecture of ISO 10646 and CJK Unified Ideographs
of the BMP |
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As
mentioned previously, the encoding architecture of
ISO 10646 is four-octet. It is illustrated below: |
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 |
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From
the diagram above, it can be seen that the whole UCS
code consists of 128 Groups (Group 00 - 7F) and each
group contains 256 Character Planes (Plane 00 - FF);
each character plane has 256 Rows (Row 00 - FF); each
row consists of 256 Cells (Cell 00 -FF). Hence each
character plane can accommodate 256 x 256 (total of
65,536) code spaces for character coding. |
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The
1993 version only defined the above-mentioned fundamental
architecture and characters in the BMP; there was
no standard for other groups and character planes.
After 1996, WG2 has set the application procedures
for UTF-16 Interchange Forms, character planes other
than the BMP was also defined. It is summarized below: |
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Group
0 of ISO 10646
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Encoding
Contents
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Encoding
Style
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| Plane
0(BMP) |
Frequently
Used Universal Character Set (include Han characters
and other characters) |
two-octet
encoding |
| Plane
1(Supplementary Character Plane 1) |
Characters
other than Han characters that have not been coded |
Four-octet encoding
Use the UTF-16 procedure to intercept characters |
| Plane
2(Supplementary Character Plane 2) |
Han
characters that have not been coded |
| Plane
3 ~ 13 |
Reserved
for future coding |
| Plane
14 |
Tag
Characters |
| Plane
15 ~ 16 |
User-defined
areas |
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In
the 1993 version, the BMP was made up by four major
parts, "A", "I", "O" and "R". But it was amended to
comprise of five areas "A", "I", "O", "S", and "R".
Area "S" is mainly for the operation of UTF-16. |
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| ¡@ |
Contents
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Code
Position
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Number
of codes
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Area
"A"
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Pin-Yin
alphabets, symbols and other symbols |
0000
¡ã 4DFF
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19,903
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Area
"I"
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GJK
Han characters area |
4E00
¡ã 9FFF
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20,992
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Area
"O"
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Reserved
for future used |
A000
¡ã D7FF
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14,336
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Area
"S"
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UTF-16
operating area |
D800
¡ã DFFF
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2,048
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Area
"R"
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Private
Use Area (user/ manufacturer) |
E000
¡ã FFFD
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8,192
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Although
the above zoning principles apply to coding, due to
the overall consideration given to code positions
and areas at the actual time of coding, the current
contents of BMP differed from those described above.
A typical example is the character set of "CJK Unified
Ideographs Extension A", containing 6,582 characters.
Due to the fact that only scattered positions were
left in area "I", these characters were coded in area
"A" in positions 3400 - 4DFF, which was originally
intended for Hangul symbols. But since Hangul symbols
were re-located to area "O", the vacated code positions
accommodated the character set of "CJK Unified Ideographs
Extension A". Hence, in reality, actual coding was
different to that based on theory. |
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It
was required to unify CJK Han characters in area "I"
because at the time of initial coding, Han characters
used in the respective countries were not quite the
same. For this, the SC2/WG2 invited specialists from
each country forming the CJK/JRG, the former IRG to
unify the entire character sets. CJK/JRG accomplished
this difficult task after five meetings. References
used to unify the GJK Unified Ideographs included:
Character Planes 1, 2 and 14 (Column T) of the 1986
version of CNS 11643 and standard character sets from
China's GB 2312¡BGB 12345¡BGB 7589¡BGB 17590¡BGB 8565(Column
G), Japan's X 0208¡BJIS X 0212(Column J) and South
Korea's KS C 5601¡BKSC 5667(Column K). Frequently used
characters in the four regions have been incorporated.
The characters were coded based on Kang-Shi Dictionary,
Ta-Han-Ho Dictionary, Han Language Master Dictionary
and Ta-Chi-Yuan Dictionary, in the order of radicals
and then stroke order. The CJK/JRG passed the results
onto SC2/WG2 for coding which completed the coding
of 20,902 CJK Unified Ideographs in area I of the
BMP, version ISO 10646:1993. Of the 20,902 characters
coded, 17,011 characters were from the CNS 11643 character
set. |
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The
CJK Unified Ideographs of BMP did not incorporate
all Asian ideographs due to limited space. Consequently,
it was difficult to satisfy the requirements of the
respective countries. It was a consensus that the
character sets of Unified Ideographs defined in BMP
need to be extended. As a result, in 1993, the ISO
established the Ideograph Rapporteur Group under the
SC2/WG2 working group, focusing on the work of Internal
/ Horizontal Supplementation and External / Vertical
Extension of the CJK Unified Ideographs. Participants
in this project included China, Taiwan, Japan, Korea,
Hong Kong, Unicode Consortium, the USA, Vietnam and
Singapore. |
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Since
the establishment of the IRG, based on the custom
of organizing meetings in turn and that two meetings
were held each year, twelve meeting have been held
to discuss the principles of extending the ideographs
character sets of ISO10646's BMP and to unify and
sort out characters proposed by each country. In 1998,
the IRG completed the CJK Unified Ideographs Extension
A, containing a total of 6,582 characters and was
approved by SC2/WG2. It was planned to code these
characters in 3400 - 4DFF of BMP's area A; a total
of 5,879 CNS11643 characters were included. The major
difference of this character set to that of CJK Unified
Ideographs defined in area I was that, in addition
to columns G, T, J and K, there was an additional
column V to accommodate Vietnamese. |
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Subsequent
to these two stages of unification and extension of
the Chinese Ideographs Sets, BMP has incorporated
a sum of 27,848 ideographs. There was hardly any large
space left for continuous coding. However, Chinese
characters are large in number and the second supplementary
character plane of ISO 10646 was planned for Chinese
character extension; therefore, the extension of ideographs
is still on going. The IRG's most important task at
present is CJK Unified Ideographs Extension B. This
character set will incorporate all characters included
in Kang-Shi Dictionary, Han Language Master and national
standard character sets of China, Taiwan, Korea, Vietnam
and Hong Kong. The objective is to incorporate more
Chinese characters into ISO 10646 to satisfy the needs
of using major character sets by the respective nations.
The extension used the Kang-Shi Dictionary and the
Han Language Master Dictionary as the fundamental
source of characters; characters that were already
coded in ISO 10646 were eliminated and character sets
proposed by the respective nations were added. The
work was undertaken in accordance with recognized
regulations. Extended B character set will be coded
in Supplementary Plane 2. At present, the total number
has reach some 40,000 characters amongst which included
approximately 30,000 characters from character planes
4 to 7 of CNS 11643. It is expected that after the
extension work is completed, 95% of the characters
defined in CNS 1643 character planes 1 to 7 will be
collected in the ISO 10646 standard. The rem | |
