In formal Cantonese, the 圓 or 元 (Cantonese Yale: yùn) character is used. In informal Cantonese, 蚊 (Cantonese Yale: mān) is used. The use of the character 蚊 (mān) originate from the tone change of the currency denomination used in China in imperial times 文 (Cantonese Yale: màn), which was the chief denomination until the introduction of the yuan in the late 19th century.