Cheng-hua: Year 22, Month 7, Day 16
15 Aug 1486
It was Imperially commanded that merchants be summoned to purchase 34,100-plus yin of tax salt from the Hei, Bai, An-ning and Wu-jing Salt Supervisorates in Yun-nan, in order to provide for the due needs of the border troops. It was stipulated that each yin be sold for four qian five fen [of silver]. This was ordered in accordance with a request by the Censor-in-Chief Cheng Zong, grand coordinator of Yun-nan.
Zhong-yang Yan-jiu yuan Ming Shi-lu, volume 50, page 4721