CJK Unified Ideographs Extension B
| CJK Unified Ideographs Extension B | |
|---|---|
| Range | U+20000..U+2A6DF (42,720 code points) |
| Plane | SIP |
| Scripts | Han |
| Assigned | 42,720 code points |
| Unused | 0 reserved code points |
| Unicode version history | |
| 3.1 (2001) | 42,711 (+42,711) |
| 13.0 (2020) | 42,718 (+7) |
| 14.0 (2021) | 42,720 (+2) |
| Chart | |
| Code chart | |
| Note: [1][2] | |
CJK Unified Ideographs Extension B is a Unicode block containing rare and historic CJK ideographs for Chinese, Japanese, Korean, and Vietnamese.
The block has dozens of variation sequences defined for standardized variants.[3]
It also has thousands of ideographic variation sequences registered in the Unicode Ideographic Variation Database (IVD).[4][5] 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 After the introduction of multi-column code charts on Unicode 5.2, the original glyphs were retained under the UCS2003 source identifier until Unicode 14.0.[6] 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.
Known issues[]
Unifiable variants and exact duplicates in Extension B[]
Also in CJK Unified Ideographs Extension B, hundreds of glyph variants were encoded.[7] In addition to the deliberate encoding of close glyph variants, six exact duplicates (where the same character has inadvertently been encoded twice) and two semi-duplicates (where the CJK-B character represents a de facto disunification of two glyph forms unified in the corresponding BMP character) were encoded by mistake:[8]
- U+34A8 㒨 = U+20457