Kuangmiu zhengsu 匡謬正俗 "Rectification of errors and corrections of the unorthodox" is a handbook on typical writing errors compiled during the Tang period 唐 (618-907) by the scholar Yan Shigu 顏師古 (581-645). The book was acutally not finished, but was submitted to the throne in 651 by Yan's son Yan Yangting 顏揚庭 (d. 690). At that time it had a length of 8 juan. The book survived as part of the library of the Imperial Archives (Mishuge 秘書閣).
During the Song period 宋 (960-1279) it was called Kanmiu zhengsu 刊謬正俗, in order to avoid the personal name of the dynasty's founder, Zhao Kuangyin 趙匡胤 (Song Taizu 宋太祖, r. 960-975). In 182 paragraphs, Yan Shigu points at writing errors in the common versions of important classical writings. Although seldomly consulted today, the Kuangmiu zhengsu is one of the first books in which textual critique was developed as an important tool for the study of ancient writings. In bibliographies, the Kuangmiu zhengsu belongs to the category of books of "lesser learning" (Xiaoxue 小學), often translated as "lexicography".
The oldest surviving editions of the book in the series Yayutang cangshu 雅雨堂藏書 and Shiliju congshu 士禮居叢書 are not very reliable and full of clerical errors. A relatively good version was published in 1814 by Zhang Shaoren 張紹仁 which is now kept in the Beijing Library 北京圖書館. The Kuangmiu zhengsu is also included in the imperial series Siku quanshu 四庫全書.