Two pages from 'Chi dien phu' handwritten in Han-Nom. Probably 19th century. Chu Nom is an obsolete writing system of the Vietnamese language. It makes use of Chinese characters (known as Han Tu in Vietnamese), and characters coined following the Chinese model. The earliest known example of Chu Nom dates to the 13th century. It was used almost exclusively by the Vietnamese elite, mostly for recording Vietnamese literature (formal writings were, in most cases, not done in Vietnamese, but in classical Chinese). It has almost been completely replaced by Quoc Ngu, a script based on the Latin alphabet.