Modifier Tone Letters Unicode Block

Modifier Tone Letters is a set of spacing diacritical marks used primarily in the phonetic transcription of certain African and Asian languages, especially for marking tone contours on adjacent vowels or syllables. These characters, which are visually distinct from combining diacritics, include high, mid, low, rising, and falling tone bars, as well as complex contour tones like glottalized and extra-high variants. They are intended for use in linguistic notation rather than in everyday orthography, and they appear as separate glyphs that can be placed before or after the target segment, offering a more precise representation of pitch patterns than standard accent marks. This set complements other phonetic tools by enabling clear, unambiguous tone marking in scholarly and educational texts.