Universal Character Set Characters - Divisions of UCS

Divisions of UCS

The UCS can be divided in various ways: plane, category, block, etc. Unicode and ISO divide it into 17 planes, each capable of containing 65,534 distinct characters or 1,114,078 total. As of 2007 (Unicode 5.0) ISO and the Unicode Consortium has only allocated characters and blocks in six of the 17 planes The others remain empty and reserved for future use.

1. Basic Multilingual Plane (BMP). This plane contains most of the characters needed for scripts and languages in routine use in the world today. The plane is nearly filled with only approximately 3,700 of the 65,534 code points remaining to be defined.
2. Supplementary Multilingual Plane (SMP). Currently used for many ancient scripts and characters as well as musical and mathematical notation.
3. Supplementary Ideographic plane (SIP). Used for ideographic characters used in many languages in China, Japan, Korea, Taiwan, Vietnam and Singapore.
4. Supplementary Special-purpose Plane (SSP). For special-purpose characters such as compatibility control characters.
5. Private Use Plane A. Together the Private Use planes provide 131,068 characters — in addition to the 6,400 private use code points provided in the BMP — for definition by organizations outside Unicode and ISO 10646. Such private use definers might be operating system vendors, font vendors, or other independent standards organizations.
6. Private Use Plane B.