The Qiandinglu 前定錄 "Previous settlements" is a collection of stories compiled by the Tang period 唐 (618-907) writer Zhong Lu 鍾輅 who flourished during the Dahe reign Dahe 大和 827-835 of Emperor Wenzong 唐文宗 (r. 826-840) and was editor (jiaoshulang 校書郎) in the Institute for the Veneration of Literature (Chongwenguan 崇文館). A book called Gandinglu 感定錄 is also attributed to him, yet this might be an error for "Qiandinglu". The bibliography Zhizhai shulu jieti 直齋書錄解題 says that there was a supplement to the Qiandinglu, including 24 additional stories to the 23 in the main text. The stories are of a various quality and of very different content, so that the Qiandinglu was never considered as a valuable text. It is nevertheless included in the imperial collectanea Siku quanshu 四庫全書, as well as in the Baichuan xuehai 百川學海, Tang-Song congshu 唐宋叢書, Shuofu 說郛, Wuchao xiaoshuo 五朝小說, Tangren shuohui 唐人說薈, and Xuejin taoyuan 學津討原.
There is another book with the same title, written by the Ming period 明 (1368-1644) scholar Cai Shanji 蔡善繼 (fl. 1615). His Qiandinglu is in large parts a collection of stories included in the Song period 宋 (960-1279) encylcopedia Taiping guangji 太平廣記.
Source: Li Xueqin 李學勤, Lü Wenyu 呂文鬰 (1996). Siku da cidian 四庫大辭典, vol. 2, p. 2139. Changchun: Jilin daxue chubanshe.