U+1D422 "𝐢" Mathematical Bold Small I Unicode Character

Unicode Version 17.0

𝐢

U+1D422 "𝐢" Mathematical Bold Small I is a typographic glyph from the Mathematical Alphanumeric Symbols block, designed to represent the lowercase letter 'i' in a bold typeface specifically for use in mathematical and scientific notation. It occupies code point 1D422 in the Unicode standard, which encodes it as a distinct character to differentiate it from the regular italic or upright small 'i', thereby preventing formatting confusion in plain text environments. This character is commonly employed in equations, proofs, and documents where variables, indices, or constant identifiers need to be clearly distinguished from ordinary text, such as in the expression "𝐢" as the imaginary unit or a vector component. Being part of Unicode's comprehensive set of mathematical letters, it ensures that authors can reliably represent bold mathematical symbols without relying on markup or proprietary fonts.

General Properties

Code Point U+1D422
Version Added 3.1
Name Mathematical Bold Small I
Block Mathematical Alphanumeric Symbols
General Category Lowercase Letter
Canonical Combining Class Not Reordered
Bidirectional Class Left To Right
Decomposition Type Font
Decomposition Mapping "i" U+0069 Latin Small Letter I

Encodings

HTML Decimal Encoding 𝐢
HTML Hex Encoding 𝐢
UTF-8 Encoding 0xF0 0x9D 0x90 0xA2
UTF-16 Encoding 0xD835 0xDC22
UTF-32 Encoding 0x0001D422
C/C++/Java Escape \ud835\udc22

Unicode Properties

NFC Quick Check Yes
NFD Quick Check Yes
Numeric Type None
Numeric Value NaN
Line Break Alphabetic
Lowercase Yes
Cased Yes
Changes When NFKC Casefolded Yes
NFKC Casefold "i" U+0069 Latin Small Letter I
NFKC Simple Casefold "i" U+0069 Latin Small Letter I
Script Common
Script Extensions Common
Indic Syllabic Category Other
ID Start Yes
XID Start Yes
ID Continue Yes
XID Continue Yes
Soft Dotted Yes
Alphabetic Yes
Math Yes
Other Math Yes
Vertical Orientation Rotated
Grapheme Base Yes
Grapheme Cluster Break Other
Word Break Alphabetic letter
Sentence Break Lower