The Unicode Standard is very closely aligned with the international
standard ISO/IEC 10646 (also known as the Universal Character Set, or
UCS, for short). Close cooperation and formal liaison between the
committees has ensured that all additions to either standard are
coordinated and kept in synch, so that the two standards maintain exactly
the same character repertoire and encoding. The Unicode encoding forms
correspond exactly to the encoding forms also defined in ISO/IEC 10646.
- www.unicode.org/standard/principles.html