language is tonal. A tonal language relies on differences and inflections in the tone of a word to reflect the meaning of that word. These phonetic symbols indicate the tone of the spoken word, or represent instead a homonym of the intended word.

The origin of the Mixtec writing system is unknown, but other Mesoamerican pre-Columbian writing systems, such as that of the Aztecs, are found to have similar traits. The Mixtec writing system is found on codices dating to the Post-Classic period preceding the arrival of the Europeans in