Latin Subscript Small Letter I

Latin Subscript Small Letter I at U+1D62 is a small baseline-lowered form of the Latin letter i used as a phonetic and notational letter, not as automatic formatting. It belongs to the Phonetic Extensions block and is encoded as its own character for cases where the subscript i itself carries meaning. Its most common appearance is in technical notation, especially mathematics, physics, chemistry, and engineering, where it can label an indexed quantity directly in plain text: xᵢ means the i-th member of a sequence, vᵢ can mean an initial or indexed velocity, and Cᵢ may mark a concentration or component. In polished mathematical typesetting this is often produced by layout rather than this character, but U+1D62 is useful in filenames, identifiers, database labels, and other plain-text settings. In phonetic and linguistic material, subscript Latin letters can mark secondary articulation, reduced segments, or fine distinctions in transcription systems outside ordinary spelling. This character may also occur in scholarly transliteration, interlinear notes, and compact annotation where a true subscript i is preferred over a full-size letter. A practical caution is that it is not the same as applying subscript styling to the normal letter i, so searching for one form may not find the other. It can also be visually small enough to resemble a dot or mark in some fonts.