⼝

{| style="border: 2px solid #4B4B55; width: min(100%, 380px);" darkstyle="border-color: #48484a;"
|-
| colspan="4" style="text-align: center; font-size: 5em; padding: 26px 0; line-height: 1; color: #4B4B55;" darkstyle="color: var(--wiki-color);" | ⼝
|-
! style="color: #4B4B55; text-align: left; width: 34%; padding: 6px 10px; border-bottom: 1px solid #eee;" darkstyle="color: var(--wiki-color); border-color: #2c2c2e;" | Unicode name
| colspan="3" style="padding: 6px 10px; border-bottom: 1px solid #eee;" darkstyle="border-color: #2c2c2e;" | Kangxi Radical Mouth
|-
! style="color: #4B4B55; text-align: left; padding: 6px 10px; border-bottom: 1px solid #eee;" darkstyle="color: var(--wiki-color); border-color: #2c2c2e;" | Code point
| style="padding: 6px 10px; width: 16%; border-bottom: 1px solid #eee;" darkstyle="border-color: #2c2c2e;" | U+2F1D
! style="color: #4B4B55; text-align: left; width: 34%; padding: 6px 10px; border-bottom: 1px solid #eee;" darkstyle="color: var(--wiki-color); border-color: #2c2c2e;" | Radical
| style="padding: 6px 10px; width: 16%; border-bottom: 1px solid #eee;" darkstyle="border-color: #2c2c2e;" | 30
|-
! style="color: #4B4B55; text-align: left; padding: 6px 10px; border-bottom: 1px solid #eee;" darkstyle="color: var(--wiki-color); border-color: #2c2c2e;" | Block
| colspan="3" style="padding: 6px 10px; border-bottom: 1px solid #eee;" darkstyle="border-color: #2c2c2e;" | Kangxi Radicals (U+2F00–U+2FDF)
|-
! style="color: #4B4B55; text-align: left; padding: 6px 10px; border-bottom: 1px solid #eee;" darkstyle="color: var(--wiki-color); border-color: #2c2c2e;" | Character
| colspan="3" style="padding: 6px 10px; border-bottom: 1px solid #eee;" darkstyle="border-color: #2c2c2e;" | <div>[[口]] (U+53E3)</div>
|-
! style="color: #4B4B55; text-align: left; padding: 6px 10px; border-bottom: 1px solid #eee;" darkstyle="color: var(--wiki-color); border-color: #2c2c2e;" | Decomposition
| colspan="3" style="padding: 6px 10px; border-bottom: 1px solid #eee;" darkstyle="border-color: #2c2c2e;" | Compatibility, to U+53E3
|-
! style="color: #4B4B55; text-align: left; padding: 6px 10px;" darkstyle="color: var(--wiki-color);" | Normalizes under
| colspan="3" style="padding: 6px 10px;" | NFKC, NFKD
|}

{{ The Unicode Kangxi Radicals block Navbox }}

'''⼝''' is a Unicode character at '''U+2F1D''', named Kangxi Radical Mouth. It is not a Chinese character in ordinary use. If you arrived here after copying a glyph out of a radical chart or a dictionary index, the character you almost certainly want is '''[[口]]''' at U+53E3.

The two look identical in most fonts and mean the same thing, but they are separate code points, and software treats them as unrelated. A search for ⼝ will not find text containing 口.

= What this code point is for =

Unicode encodes the 214 [[Kangxi radicals]] a second time, in a block of their own, so that a radical chart can be typeset as a chart. A table of radicals is a list of abstract indexing elements rather than a passage of text, and giving those elements their own code points lets a font apply chart-specific shapes and spacing without disturbing how the same glyph is drawn in running prose.

The block also serves round-trip compatibility with older East Asian character sets that had made the same separation.

Neither purpose involves writing words. ⼝ should not appear in article text, page titles, search queries, filenames, or any other place where the character [[口]] is meant.

= Normalization behavior =

⼝ carries a '''compatibility''' decomposition to U+53E3. That determines exactly which normalization forms will convert it:

* '''NFKC''' and '''NFKD''' convert ⼝ to 口
* '''NFC''' and '''NFD''' leave it unchanged

This is the practical trap. Compatibility decompositions are weaker than canonical ones, and most systems that normalize silently — file systems, database indexes, web forms — apply NFC rather than NFKC. So ⼝ survives in places where a canonically-decomposable character would have been folded, and two strings that look identical on screen compare as different.

The [[CJK Radicals Supplement]] block is worse in this respect. Of its 115 characters, only two carry any decomposition at all, so the remaining 113 will never normalize to anything under any form. A radical glyph copied from that block is permanently distinct from the character it depicts.

= See also =

* [[口]]
* [[CJK Radicals Supplement]]
* [[Kangxi radicals]]
* [[Unicode normalization]]

= Further reading =

* [https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-18/ The Unicode Standard, Chapter 18: East Asia] — defines the Kangxi Radicals and CJK Radicals Supplement blocks and their intended use
* [https://www.unicode.org/reports/tr38/ Unicode Standard Annex #38] — the Unihan database, including the radical-stroke indexing this block supports