Block: Modifier Tone Letters

Range U+A700 - U+A71F
Official Chart http://www.unicode.org/charts/PDF/UA700.pdf
Wikipedia Modifier Tone Letters is a Unicode block containing tone markings for Chinese, Chinantec, Africanist, and other phonetic transcriptions. It does not contain the standard IPA tone marks, which are found in Spacing Modifier Letters. ⟨꜀◌ ꜁◌ ꜂◌ ꜃◌ ◌꜄ ◌꜅ ◌꜆ ◌꜇⟩ are used to mark yin and (underlined) yang splits of the ping, shang, qu and ru tones, respectively, in the etymological four-tone analysis of Chinese.
https://en.wikipedia.org/wiki/Modifier_Tone_Letters
Characters