ISO/IEC 10646:2003 Withdrawn

Information technology -- Universal Multiple-Octet Coded Character Set (UCS)



ISO/IEC 10646:2003 specifies the Universal Multiple-Octet Coded Character Set (UCS). It is applicable to the representation, transmission, interchange, processing, storage, input and presentation of the written form of the languages of the world as well as additional symbols.

ISO/IEC 10646:2003
  • specifies the architecture of ISO/IEC 10646:2003;
  • defines terms used in ISO/IEC 10646:2003;
  • describes the general structure of the coded character set;
  • specifies the Basic Multilingual Plane (BMP) of the UCS;
  • specifies supplementary planes of the UCS: the Supplementary Multilingual Plane (SMP), the Supplementary Ideographic Plane (SIP) and the Supplementary Special-purpose Plane (SSP);
  • defines a set of graphic characters used in scripts and the written form of languages on a world-wide scale;
  • specifies the names for the graphic characters of the BMP, SMP, SIP, SSP and their coded representations;
  • specifies the four-octet (32-bit) canonical form of the UCS: UCS-4;
  • specifies a two-octet (16-bit) BMP form of the UCS: UCS-2;
  • specifies a multiple byte (one to four) byte transformation UTF-8 for use with ISO 646 (ASCII) byte-oriented environments;
  • specifies a two 16-bit form and associated transformation UTF-16 for supplementary characters;
  • specifies collection identifiers for selected set of character subsets;
  • specifies the coded representations for control functions;
  • specifies the management of future additions to this coded character set;
  • incorporates the Unicode bi-directional algorithm and normalization forms by reference.

The UCS is a coding system different from that specified in ISO/IEC 2022. A graphic character will be assigned only one code position in ISO/IEC 10646:2003, located either in the BMP or in one of the supplementary planes.

NOTE - The Unicode Standard, Version 4.0 includes a set of characters, names, and coded representations that are identical with those in ISO/IEC 10646:2003. It additionally provides details of character properties, processing algorithms, and definitions that are useful to implementers. Version 4.0 strengthens Unicode support for worldwide communication, software availability, and publishing.

By defining a consistent way of encoding multilingual text ISO/IEC 10646:2003 enables the exchange of data internationally. The information technology industry gains data stability, greater global interoperability and data interchange. ISO/IEC 10646:2003 has been widely adopted in new Internet and W3C protocols and mark up languages such as XML and HTML, and implemented in modern operating systems and computer programming languages. This edition covers over 96 000 characters from the world's scripts.

Additional information

Publication typeInternational Standard
Publication date2003-12-15
Available language(s)English, French
TC/SCISO/IEC JTC 1/SC 2 - Coded character setsrss
ICS35.040.10 - Coding of character sets

The following test report forms are related:

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