(UCS, ISO/IEC 10646) A 1993 ISO and IEC standard character set, also known as "Universal Multiple-Octet Coded Character Set".UCS comes in a 16-bit variant called UCS-2 and a 32-bit variant called UCS-4, which is composed of 16-bit UCS-2 "planes".So far only one 16-bit plane has been defined, which is known as the Basic Multilingual Plane.The implementation of UCS is still in its infancy, though some moves, such as the Java language defining a character to be 16 bits, are suggestive.[Relationship with Unicode?](1997-07-04)