RE: Unicode Standard & ISO-10646 Standard

From: Hart, Edwin F. (
Date: Tue May 11 1999 - 09:33:43 EDT

Se˝or Benet,

In 1991, the ISO Working Group responsible for ISO/IEC 10646 (JTC 1/SC 2/WG
2) and the Unicode Consortium decided to create one universal standard for
coding multilingual text. ISO published its version as ISO/IEC 10646-1:
1993 and Unicode published its version as Unicode Version 1.1 (a Unicode
Technical Report describes the differences between the version 1.0 books and
version 1.1). Since then, the ISO 10646 Working Group (SC 2/WG 2) and the
Unicode Consortium have worked together very closely to extend the standard
and to keep their respective versions synchronized.

Unicode Version 2.1 is compliant with ISO/IEC 10646-1: 1993 with amendments
1 to 9. It implements the UCS-2 coded representation form (using UTF-16),
implementation level 3, and the full subset of the Basic Multilingual Plane
or BMP (numbered subset 300). (See _The Unicode Standard, Version 2.0_,
section C.5, "The Unicode Standard as a Profile of 10646", on page C-4.)

In addition to using the same code as ISO/IEC 10646, the Unicode Standard
includes supplementary information required to implement ISO/IEC 10646.
This information is the character properties, the algorithm for handling
bi-directional text, etc. Chapter 3 of _The Unicode Standard, Version 2.0_
book describes the requirements for conformance to Unicode.

For your information, the Unicode Consortium is preparing version 3.0 for
its standard and ISO is preparing the second edition of the ISO/IEC 10646
standard. I would suspect that both standards will be available by this
time next year.

I hope that this helps clarify the situation.

Best regards,
Ed Hart

Edwin F. Hart
Applied Physics Laboratory
11100 Johns Hopkins Road
Laurel, MD 20723-6099
+1-240-228-6926 (from Washington, DC area)
+1-443-778-6926 (from Baltimore area)
+1-240-228-1093 (fax) <>

                -----Original Message-----
                From: Ricardo Bermell Benet []
                Sent: 11 May, 1999 04:15
                To: Unicode List
                Subject: Unicode Standard & ISO-10646 Standard

                I don't fully understand the relation between ISO-10646 and

                The most I know is that ISO-10646 is an international
                proposed by public national organizations of many countries,
                Unicode is a "standard based in" or ┐implementation of?
                proposed by major American (United States) private

                Not in Unicode site nor in other sites related to these
                have i found a satisfactory answer.

                Following one finds:
                << The Unicode Standard is a subset of and code for code
                to the International Standard ISO/IEC 10646-1:1993 >>

                ┐Is it a subset? If so, why don't use ISO-10646 as a better
(wider) standard.
                ┐Isn't ISO-10646 usable directly for the same purposes?
                ┐"Code for code"? ┐What does it mean precisely "to code"
                ┐Is Unicode "code" identical to ISO "code"?
                ┐Is the diference that Unicode supplies algorithms?
                ┐? I'm confused

                Ricardo Bermell-Benet

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