level and oblique tones (technical term for Classical Chinese rhythmic poetry)
四声
sì shēng
the four tones of Middle Chinese: level tone 平聲|平声, rising tone 上聲|上声, departing tone 去聲|去声 / and entering tone 入聲|入声 / the four tones of Modern Standard Mandarin
nine tones and six modes (tonal system of Cantonese and other southern languages)
龙龛手鉴
Lóng kān Shǒu jiàn
Longkan Shoujian, Chinese character dictionary from 997 AD containing 26,430 entries, with radicals placed into 240 rhyme groups and arranged according to the four tones, and the rest of the characters similarly arranged under each radical