Johab Code (KS C 5601-1992)Johab Code provides all 11,172 Hangul characters by composing them with five-bit codes for the 19 leading consonants, 21 vowels, and 28 trailing consonants (19 * 21 * 28 = 11,172).
Unified Hangul CodeUnified Hangul Code (UHC) extends Wansung Code by adding the missing 8,822 Hangul characters, and is designed for smooth migration to Unicode Version 2.0. All Wansung code points map directly to the same UHC code points (but not vice versa). UHC also provides round trip mapping with Unicode Version 2.0. UHC is used in Korean versions of Windows 95 and Windows NT.
Wansung Code (KS C 5601-1987)Wansung Code provides 2,350 Hangul characters, 4,888 Hanja characters, and 986 other characters, such as symbols.
Unicode Version 2.0Unicode Version 2.0 includes a new starting code point for Hangul, U+AC00, that is identical in order to Johab.
Windows 95 and Windows NT Korean version are based on Unicode 2.0, and future Windows systems will also be based on Unicode 2.0.