Yuán-dynasty Daoist editor and jízhù 集註 (“collected glosses”) compiler, hào Xuányángzǐ 玄陽子 (“Master of Mysterious Yáng”), active c. 1330–1344. Known chiefly for two paired jízhù editions of foundational Daoist scriptures:

Both works were “found” and printed by Xú, according to the colophon by the thirty-ninth Celestial Master Zhāng Sìchéng 張嗣成 (d. 1344). Both commentaries appear to be based on divinatory-dream (jiàngbǐ 降筆) revelation; Xú is thus a key figure in the late-Yuán Shénxiāo fújī 扶乩 commentarial revelation tradition. No CBDB record was found.