ˬ

Symbol

 * 1)  pre-voiced.
 * 2)  post-voiced.
 * 3)  a low falling–rising tone.

Usage notes
The mark is placed before the word or syllable that bears the tone. This symbol is effectively obsolete, having been replaced by and tone diacritics.

Letter

 * 1) low tone.

Letter

 * 1) low falling tone.