What ᶸ means
It marks a brief or secondary small-capital U.
A vowel modifier can mark a short sound leading into or out of a vowel—an on-glide or off-glide—instead of the main vowel. Its raised placement makes U a secondary element; the IPA writes the related full vowel as ʊ.
In phonetic data, use the encoded character rather than styling a lowercase u: Unicode-aware HTML uses ᶸ; a programming language with Unicode escapes uses \u1DB8.
Where did ᶸ's phonetic use come from?
It belongs to a documented phonetic convention, not a single invention.
Frachtenberg's 1922 descriptions of the Siuslaw and Coos languages use superscript small-cap vowels. A 2003 encoding proposal describes vowel modifiers as on-glide and off-glide markers and records small-capital U as an Americanist option.
A 2024 Unicode proposal cites those examples and notes that superscripts vary in size and alignment. This shows the convention by 1922, not the first appearance of exact glyph ᶸ. Its reading depends on the transcription system: Americanist ᴜ may correspond to IPA ʊ, while Unicode's character notes mark ᶸ “not for UPA” (the Uralic Phonetic Alphabet).
It signals specialist phonetic notation, especially Americanist transcription.
Don't substitute it for IPA ʊ: the raised modifier and the full vowel symbol do different jobs.
Don't confuse it with
3Questions people ask
2Is ᶸ part of the IPA?
No. As of 2026, the IPA vowel chart lists ʊ for the related vowel, not ᶸ; ᶸ is a specialized phonetic modifier.
Why can ᶸ look like a normal superscript u?
They can. A 2024 Unicode proposal compares historical examples whose superscripts differ in size and alignment, making the small-cap distinction easy to miss. The encoded character and transcription key identify its role.
How to type ᶸ
ᶸ\1DB8Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.