Proto-Mandarin

Proto-Mandarin is a term that can be used to designate any earlier form of the most widely-spoken dialect, known in as ; technically the "late Middle Chinese" of the Song Dynasty. "Early Mandarin" is the common name for the sound system described by the rhyme dictionary ''Zhōngyuán Yīnyùn'' of the later Yuan dynasty, used for rhyming of Zaju of that time.