when it represents a coronis resulting from a crasis implying a vowel bearing a spiritus asper. The spiritus asper merely notes the presence of an initial consonant [h], which cannot be written otherwise when it is not initial: thus stands for humnos, "hymn", and for hrêtôr (or rhêtôr), "orator".
When a word begins by an initial grapheme which is a vowel not preceded by an [h], the spiritus lenis ("soft breathing") is employed.
It is part of the traditional polytonic orthography for Greek, but has been dropped in the modern monotonic orthography as the [h] sound has disappeared from Modern Greek. The origin of the sign is thought to be the left-hand half ( ├ ) of the letter H, which was used in some Greek dialects as an [h] while in others it was used for the vowel eta.
Dasia pneumata were also used in the early Cyrillic alphabet when writing the Old Church Slavonic language. In this context it is encoded as Unicode U+0485 or HTML entity ҅ ( ).
See also
