Ming Shilu
An entry in the "Ming Shilu" (traditional Chinese: 明實錄; simplified Chinese: 明实录) dated 15 August 1406 recorded an imperial order from Emperor Yongle that instructed for Vietnamese records such as maps and registers to be saved and preserved by the Chinese army:己未敕征討安南總兵官成國公朱能等曰師入安南下郡邑凡得文籍圖志皆勿毀。In addition, according to "Yueqiaoshu" (Chinese: 越嶠書, Vietnamese: Việt kiệu thư), on August 21, 1406, the Yongle Emperor issued an order to Ming soldiers in Annam:兵入。除釋道經板經文不燬。外一切書板文字以至俚俗童蒙所習。如上大人丘乙已之類。片紙隻字悉皆燬之。其境內中國 所立碑刻則存之。但是安南所立者悉壞之。一字不存。