information:extraction, structural:scholar_edition, stylistic:style_transfer, structural:reformatting
Superscript letters

Superscript IPA letters are used to indicate secondary aspects of articulation. These may be aspects of simultaneous articulation that are considered to be in some sense less dominant than the basic sound, or may be transitional articulations that are interpreted as secondary elements. Examples include secondary articulation; onsets, releases and other transitions; shades of sound; light epenthetic sounds and incompletely articulated sounds. Morphophonemically, superscripts may be used for assimilation, e.g. ⟨ aʷ ⟩ for the effect of labialization on a vowel /a/, which may be realized as phonemic /o/. The IPA and ICPLA endorse Unicode encoding of superscript variants of all contemporary segmental letters, including the "implicit" IPA retroflex letters ⟨ ꞎ 𝼅 𝼈 ᶑ 𝼊 ⟩.

Superscripts are often used as a substitute for the tie bar, for example ⟨ tᶴ ⟩ for and ⟨ kᵖ ⟩ or ⟨ ᵏp ⟩ for. However, in precise notation there is a difference between a fricative release in and the affricate, between a velar onset in and doubly articulated.

Superscript letters can be meaningfully modified by combining diacritics, just as baseline letters can. For example, a superscript dental nasal in ⟨ ⁿ̪d̪ ⟩, a superscript voiceless velar nasal in ⟨ ᵑ̊ǂ ⟩, and labial-velar prenasalization in ⟨ ᵑ͡ᵐɡ͡b ⟩. Although the diacritic may seem a bit oversized compared to the superscript letter it modifies, e.g. ⟨ ᵓ̃ ⟩, this can be an aid to legibility, just as it is with the composite superscript c-cedilla ⟨ ᶜ̧ ⟩ and rhotic vowels ⟨ ᵊ˞ ᶟ˞ ⟩. Superscript length marks can be used to indicate the length of aspiration of a consonant, e.g.. Another option is to use extIPA parentheses and a doubled diacritic: ⟨ p⁽ʰ⁾ tʰ kʰʰ ⟩.