Decomposition Type
Decomposition Type is a classification that explains why a character is canonically or compatibly decomposed into a sequence of other characters. It labels the reason for the decomposition, such as whether the character is a font variant, a ligature, a superscript, a fraction, a circled form, or a vertical presentation. This distinction matters because canonical decompositions preserve the visual and semantic identity of a character, while compatibility decompositions indicate that the original form is a stylistic or formatting variation that may not be equal in meaning, for example, a fullwidth digit decomposing to its standard counterpart. The type values like <font>, <compat>, <super>, <sub>, <fraction>, <circled>, and <narrow> help software decide when to perform normalization for text comparison or search, ensuring that equivalent sequences are treated consistently without altering intended distinctions.
- Abbr
- can
- Count
- 13253
Canonical is the decomposition type indicating a character’s base form, unmarked by formatting distinctions, used for compatibility normalization.
- Abbr
- com
- Count
- 721
Compat is a marker indicating a character’s decomposition is a formatting or compatibility variant, not a canonical equivalence.
- Abbr
- enc
- Count
- 240
Circle is a decomposition type indicating a character is a circled variant of its base form, often for enclosed alphanumerics or symbols.
- Abbr
- fin
- Count
- 240
Final is the value indicating a character’s decomposition is a canonical equivalent, not a compatibility or other styled variant.
- Abbr
- font
- Count
- 1231
Font is a decomposition type indicating a character is a formatting variant, like a swash or styled form, rather than a distinct semantic unit.
- Abbr
- fra
- Count
- 20
Fraction is a decomposition type indicating a character should display as a vulgar fraction, like ½, composed of a numerator, slash, and denominator.
- Abbr
- init
- Count
- 171
Initial is a tag indicating a character’s decomposition occurs in an initial presentation form, typically for Arabic or Syriac contextual shaping.
- Abbr
- iso
- Count
- 238
Isolated is a tag indicating a character’s decomposition is a standalone form, not tied to a specific context or style.
- Abbr
- med
- Count
- 82
Medial is a decomposition type indicating a character that appears in the middle of a word, like certain Arabic presentation forms.
- Abbr
- nar
- Count
- 122
Narrow is a decomposition type indicating a character is a narrower variant of another, often used for East Asian width compatibility.
- Abbr
- nb
- Count
- 5
Nobreak is a decomposition type indicating a no-break space, used to prevent line breaks at that point.
- Abbr
- sml
- Count
- 26
Small is a decomposition type marking a character as a diminutive variant, often used in phonetic notation or superscript-like forms.
- Abbr
- sqr
- Count
- 286
Square is a decomposition type indicating a character is a typographic ligature or symbol shaped to fill a square space, like Japanese squared katakana.
- Abbr
- sub
- Count
- 68
Sub is a formatting distinction indicating a character is a subscript form, used for typographic positioning below the baseline, as in mathematical notation.
- Abbr
- sup
- Count
- 308
Super is a formatting hint indicating a character should be displayed as a superscript, typically for mathematical or phonetic notation.
- Abbr
- vert
- Count
- 39
Vertical is a formatting hint that a character should be displayed vertically, often used for rotated or stacked forms in vertical text layouts.
- Abbr
- wide
- Count
- 104
Wide is the decomposition type indicating a character is a fullwidth variant, mapping to its narrow counterpart.
- Abbr
- none
- Count
- 293187
None is the default decomposition type, indicating a character has no canonical or compatibility decomposition mapping.