Dieses Zeichen ist ein Modifier Symbol und wird hauptsächlich in der Schrift Griechisch verwendet.
Das Zeichen ist eine Kompatibilität Zusammensetzung der Zeichen Zeichen für U+0020Space, Zeichen für U+0313Combining Comma Above. Es hat keine zugewiesene Weite in ostasiatischen Texten. In bidirektionalem Text handelt es als Other Neutral. Bei einem Richtungswechsel wird es nicht gespiegelt. Das Wort, das U+1FBF mit ähnlichen Zeichen bildet, verbietet in sich Zeilenumbrüche. Der Buchstabe kann mit einem anderen Zeichen verwechselt werden.
Die Wikipedia hat die folgende Information zu diesem Codepunkt:
The smooth breathing (Ancient Greek: ψιλὸν πνεῦμα, romanized: psilòn pneûma; Greek: ψιλήpsilí; Latin: spiritus lenis) is a diacritical mark used in polytonic orthography. In Ancient Greek, it marks the absence of the voiceless glottal fricative /h/ from the beginning of a word.
Some authorities have interpreted it as representing a glottal stop, but a final vowel at the end of a word is regularly elided (removed) when the following word starts with a vowel and elision would not happen if the second word began with a glottal stop (or any other form of stop consonant). In his Vox Graeca, W.S. Allen accordingly regards the glottal stop interpretation as "highly improbable".
The smooth breathing mark ( ᾿ ) is written as on top of one initial vowel, on top of the second vowel of a diphthong or to the left of a capital and also, in certain editions, on the first of a pair of rhos. It did not occur on an initial upsilon, which always has rough breathing (thus the early name ὕhy, rather than ὔy) except in certain pre-Koine dialects which had lost aspiration much earlier.
The smooth breathing was kept in the traditional polytonic orthography even after the /h/ sound had disappeared from the language in Hellenistic times. It has been dropped in the modern monotonic orthography.