The various types of tonal notation for Chinese have always been aligned with the Chinese tradition regarding tones and their categories. Among them, there are essentially three general strategies: to mark tone by category using name or number, by the use of added marks or diacritics, or by spelling convention. The oldest method is to simply indicate the tone category—píng 平, shǎng 上, qù 去, rù 入. Sometimes an upper and lower register distinction is indicated, as qīng 清-zhuó 濁, yīn 陰-yáng 陽, or shàng 上-xià 下. Almost as old in origin is the use of circular marks to identify the to…