The Codex Sierra is a colonial Mesoamerican account book from Santa Catalina Texupa, covering the years from 1550 to 1564. It uses both alphabetic and pictorial modes of writing. Though Texupa is a Mixtec and Chocho community, the text is written in Nahuatl, albeit with some Mixtec words. The pictorial portion likewise uses Mixtec conventions, such as the "A-O" year sign.