CJK Unified Ideographs Extension B

CJK Unified Ideographs Extension B is a Unicode block containing rare and historic CJK ideographs for Chinese, Japanese, Korean, and Vietnamese submitted to the Ideographic Research Group between 1998 and 2000, plus seven gongche characters for kunqu added in Unicode 13.0, and two characters for the Macao Supplementary Character Set added in Unicode 14.0. The block has dozens of variation sequences defined for standardized variants. It also has thousands of ideographic variation sequences registered in the Unicode Ideographic Variation Database (IVD). These sequences specify the desired glyph variant for a given Unicode character. It was the only CJK Unified Ideographs Extension block with a UCS2003 source identifier. Since Extension B contained too many characters, the original code charts were produced with a single glyph for all regions. The glyphs were designed by Beijing Zhongyi Electronic Ltd. After the introduction of multi-column code charts on Unicode 5.2, the original glyphs were retained under the UCS2003 source identifier; they were then removed in Unicode 14.0, being redundant as well as misleading. The glyphs are packaged in the "SimSun-ExtB" font distributed with the Simplified Chinese versions of Windows, and do not adhere to the glyphs for the Mainland China region.