Tenuis retroflex click
A voiceless or more precisely tenuis retroflex click is a rare click consonant. In practical orthography, an ad hoc symbol is used for the retroflex clicks; a tenuis click with a velar rear articulation is or, commonly abbreviated to, or just.
The implicit symbol in the International Phonetic Alphabet is or, abbreviated, or just. Linguists who prefer the old IPA letters use the analogous Doke convention of or, abbreviated, or. For a click with a uvular rear articulation, the equivalents are, and.
Sometimes the accompanying letter comes after the click letter, e.g. or ; this may simply be an orthographic choice, or it may imply a difference in the relative timing of the releases.