Editing Big5 (section)

====IBM code pages====
In contrast to Microsoft's code page 950, IBM's [[CCSID]] 950 comprises single byte code page 1114 (CCSID 1114) and double byte code page 947 (CCSID 947).<ref name="ccsid950">{{cite web|title=CCSID 950 information document|archive-url=https://web.archive.org/web/20141202001630/http://www-01.ibm.com/software/globalization/ccsid/ccsid950.html|archive-date=2014-12-02|url=http://www-01.ibm.com/software/globalization/ccsid/ccsid950.html}}</ref><ref>{{cite web|title=CCSID 1114 information document|archive-url=https://web.archive.org/web/20160327100728/http://www-01.ibm.com/software/globalization/ccsid/ccsid1114.html|archive-date=2016-03-27|url=http://www-01.ibm.com/software/globalization/ccsid/ccsid1114.html}}</ref><ref>{{cite web|title=CCSID 947 information document|archive-url=https://web.archive.org/web/20141201232116/http://www-01.ibm.com/software/globalization/ccsid/ccsid947.html|archive-date=2014-12-01|url=http://www-01.ibm.com/software/globalization/ccsid/ccsid947.html}}</ref> It incorporates ETEN extensions for lead bytes {{mono|0xA3}},<ref>{{cite web|url=https://demo.icu-project.org/icu-bin/convexp?conv=ibm-950_P110-1999&b=A3&s=ALL#layout|title=Lead byte A3: ibm-950_P110-1999|work=ICU Demonstration - Converter Explorer|publisher=[[International Components for Unicode]]}}</ref> {{mono|0xC6}},<ref name="rfc1922">{{citation|mode=cs1|id=<nowiki>RFC 1922</nowiki>|title=Chinese Character Encoding for Internet Messages|url=https://tools.ietf.org/html/rfc1922|first1=HF.|last1=Zhu|first2=DY.|last2=Hu|first3=ZG.|last3=Wang|first4=TC.|last4=Kao|first5=WCH.|last5=Chang|first6=M.|last6=Crispin|publisher=[[IETF]]|work=Requests for Comments|date=1996|doi=10.17487/rfc1922|doi-access=|access-date=2022-01-01|archive-date=2021-04-29|archive-url=https://web.archive.org/web/20210429165037/https://tools.ietf.org/html/rfc1922|url-status=live|url-access=subscription}}</ref><ref>{{cite web|url=https://demo.icu-project.org/icu-bin/convexp?conv=ibm-950_P110-1999&b=C6&s=ALL#layout|title=Lead byte C6: ibm-950_P110-1999|work=ICU Demonstration - Converter Explorer|publisher=[[International Components for Unicode]]}}</ref> {{mono|0xC7}}<ref>{{cite web|url=https://demo.icu-project.org/icu-bin/convexp?conv=ibm-950_P110-1999&b=C7&s=ALL#layout|title=Lead byte C7: ibm-950_P110-1999|work=ICU Demonstration - Converter Explorer|publisher=[[International Components for Unicode]]}}</ref> and {{mono|0xC8}},<ref name="rfc1922"/><ref>{{cite web|url=https://demo.icu-project.org/icu-bin/convexp?conv=ibm-950_P110-1999&b=C8&s=ALL#layout|title=Lead byte C8: ibm-950_P110-1999|work=ICU Demonstration - Converter Explorer|publisher=[[International Components for Unicode]]}}</ref> while omitting those with lead byte {{mono|0xF9}} (which Microsoft includes), mapping them instead to the [[Private Use Area]] as user-defined characters.<ref name="rfc1922"/><ref>{{cite web|url=https://demo.icu-project.org/icu-bin/convexp?conv=ibm-950_P110-1999&b=F9&s=ALL#layout|title=Lead byte F9: ibm-950_P110-1999|work=ICU Demonstration - Converter Explorer|publisher=[[International Components for Unicode]]}}</ref> It also includes two non-ETEN extension regions with trail bytes {{mono|0x81–A0}}, i.e. outside the usual Big5 trail byte range but similar to the Big5+ trail byte range: area 5 has lead bytes {{mono|0xF2–F9}} and contains IBM-selected characters, while area 9 has lead bytes {{mono|0x81–8C}} and is a user-defined region.<ref>{{cite web|url=https://public.dhe.ibm.com/as400/products/clientaccess/win32/files/globalization/T_Chinese_big51999.pdf|title=IBM Traditional Chinese Graphic Character Set for IBM BIG-5 Code|publisher=[[IBM]]|year=1999|id=C-H 3-3220-131 1999-04|access-date=2022-01-01|archive-date=2021-11-22|archive-url=https://web.archive.org/web/20211122211354/https://public.dhe.ibm.com/as400/products/clientaccess/win32/files/globalization/T_Chinese_big51999.pdf|url-status=live}}</ref>

IBM refers to the euro sign update of their Big-5 variant as CCSID 1370, which includes both single-byte ({{mono|0x80}}) and double-byte ({{mono|0xA3E1}}) euro signs.<ref name="ccsid1370">{{cite web|title=CCSID 1370 information document|archive-url=https://web.archive.org/web/20160327104212/http://www-01.ibm.com/software/globalization/ccsid/ccsid1370.html|archive-date=2016-03-27|url=http://www-01.ibm.com/software/globalization/ccsid/ccsid1370.html}}</ref> It comprises single byte code page 1114 (CCSID 5210) and double byte code page 947 (CCSID 21427).<ref name="ccsid1370"/><ref>{{cite web|title=CCSID 5210 information document|archive-url=https://web.archive.org/web/20141129231704/http://www-01.ibm.com/software/globalization/ccsid/ccsid5210.html|archive-date=2014-11-29|url=http://www-01.ibm.com/software/globalization/ccsid/ccsid5210.html}}</ref><ref>{{cite web|title=CCSID 21427 information document|archive-url=https://web.archive.org/web/20160327035914/http://www-01.ibm.com/software/globalization/ccsid/ccsid21427.html|archive-date=2016-03-27|url=http://www-01.ibm.com/software/globalization/ccsid/ccsid21427.html}}</ref> For better compatibility with Microsoft's variant in [[IBM Db2]], IBM also define the pure double-byte code page 1372<ref>{{cite web|archive-url=https://web.archive.org/web/20160317015819/http://www-01.ibm.com/software/globalization/cp/cp01372.html|archive-date=2016-03-17|url=http://www-01.ibm.com/software/globalization/cp/cp01372.html|url-status=dead|title=CPGID 01372: MS T-Chinese Big-5 (Special for DB2)|work=IBM Globalization - Code page identifiers}}</ref> and the associated variable-width CCSID 1373, which corresponds to Microsoft's code page 950.<ref>{{cite web|url=http://icu-project.org/icu-bin/convexp?conv=ibm-1373_P100-2002|title=ibm-1373_P100-2002|work=ICU Demonstration - Converter Explorer|publisher=[[International Components for Unicode]]|access-date=2022-01-01|archive-date=2021-05-26|archive-url=https://web.archive.org/web/20210526173749/https://icu4c-demos.unicode.org/icu-bin/convexp?conv=ibm-1373_P100-2002|url-status=live}}</ref>

IBM assigns CCSID 5471 to the HKSCS-2001 Big5 code page (with CPGID 1374 as CCSID 5470 as the double byte component),<ref>{{cite web|archive-url=https://web.archive.org/web/20141129233053/http://www-01.ibm.com/software/globalization/ccsid/ccsid5471.html|archive-date=2014-11-29|url-status=dead|url=http://www-01.ibm.com/software/globalization/ccsid/ccsid5471.html|work=IBM Globalization - Coded character set identifiers|publisher=[[IBM]]|title=CCSID 5471: Mixed Big-5 ext for HKSCS-2001}}</ref><ref>{{Citation|title=International Components for Unicode (ICU), ibm-5471_P100-2006.ucm|url=https://github.com/unicode-org/icu/blob/master/icu4c/source/data/mappings/ibm-5471_P100-2006.ucm|date=2007-05-09|access-date=2022-01-01|archive-date=2023-08-13|archive-url=https://web.archive.org/web/20230813202101/https://github.com/unicode-org/icu/blob/main/icu4c/source/data/mappings/ibm-5471_P100-2006.ucm|url-status=live}}</ref> CCSID 9567 to the HKSCS-2004 code page (with CPGID 1374 as CCSID 9566 as the double byte component),<ref>{{cite web|archive-url=https://web.archive.org/web/20141129212819/http://www-01.ibm.com/software/globalization/ccsid/ccsid9567.html|archive-date=2014-11-29|url-status=dead|url=http://www-01.ibm.com/software/globalization/ccsid/ccsid9567.html|work=IBM Globalization - Coded character set identifiers|publisher=[[IBM]]|title=CCSID 9567: Mixed Big-5 ext for HKSCS-2004}}</ref> and CCSID 13663 to the HKSCS-2008 code page (with CPGID 1374 as CCSID 13662 as the double byte component),<ref>{{cite web|archive-url=https://web.archive.org/web/20141129213320/http://www-01.ibm.com/software/globalization/ccsid/ccsid13663.html|archive-date=2014-11-29|url-status=dead|url=http://www-01.ibm.com/software/globalization/ccsid/ccsid13663.html|work=IBM Globalization - Coded character set identifiers|publisher=[[IBM]]|title=CCSID 13663: Mixed Big-5 ext for HKSCS-2008}}</ref> while CCSID 1375 is assigned to a growing HKSCS code page, currently equivalent to CCSID 13663.<ref>{{cite web|archive-url=https://web.archive.org/web/20141129231410/http://www-01.ibm.com/software/globalization/ccsid/ccsid1375.html|archive-date=2014-11-29|url-status=dead|url=http://www-01.ibm.com/software/globalization/ccsid/ccsid1375.html|work=IBM Globalization - Coded character set identifiers|publisher=[[IBM]]|title=CCSID 1375: Mixed Big-5 ext for HKSCS}}</ref>