ISO/IEC 10646:2017 specifies the Universal Coded Character Set (UCS). It is applicable to the represen-tation, transmission, interchange, processing, storage, input, and presentation of the written form of the lan-guages of the world as well as of additional symbols.

- specifies the architecture of this International Standard,

- defines terms used in this International Standard,

- describes the general structure of the UCS codespace,

- specifies the Basic Multilingual Plane (BMP) of the UCS,

- specifies supplementary planes of the UCS: the Supplementary Multilingual Plane (SMP), the Supplemen-tary Ideographic Plane (SIP), the Tertiary Ideographic Plane (TIP), 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 and format characters of the BMP, SMP, SIP, TIP, SSP and their coded representations within the UCS codespace,

- specifies the coded representations for control characters and private use characters,

- specifies three encoding forms of the UCS: UTF-8, UTF-16, and UTF-32,

- specifies seven encoding schemes of the UCS: UTF-8, UTF-16, UTF-16BE, UTF-16LE, UTF-32, UTF-32BE, and UTF-32LE,

- specifies the management of future additions to this coded character set.

The UCS is an encoding system different from that specified in ISO/IEC 2022. The method to designate UCS from ISO/IEC 2022 is specified in 12.2.

A graphic character will be assigned only one code point in the standard, located either in the BMP or in one of the supplementary planes.