Xiaominglu 小名錄 "On childhood names" is an encyclopaedia specialized on personal names written during the late Tang period 唐 (618-907) by Lu Guimeng 陸龜蒙 (d. 881). Lu Guimeng's writings are collected in the book Lize congshu 笠澤叢書 (correctly, Lize congshu 笠澤藂書).
The 2-juan-long (according to Zhao Xibian's 趙希弁 Qunzhai dushu houzhi 郡齋讀書後志, 3 juan) Xiaominglu deals with childhood or pet names (xiaoming 小名) of historical persons, from Empress Lü 呂后 (r. 187-180 BCE), xiaoming Exu 娥姁, to Wei Youya 魏游雅, courtesy name (zi 字) Bodu 伯度, xiaoming Huangtou 黃頭 (Northern Dynasties period, 386~581).
Some of the names cited are not really childhood names but intimate names (nicheng 暱稱 or niming 暱名), like Huhai 胡亥 for the Second Emperor of Qin 秦二世皇 (r. 209-207 BCE), or Xiu 秀 for Emperor Guangwu 光武帝 (r. 25-57 CE) of the Later Han dynasty, or colloquial names like Arong 阿戎 for Wang Rong 王戎 (234-305) or Aqian 阿謙 for Wang Sengqian 王僧謙 (426-485). The book lists between 119 and 150 names, according to different sources. There must have been a 5-juan version which was probably expanded by later persons.
The received version is definitely not the complete original. It is included in the series Siku quanshu 四庫全書.