Hong-wu: Year 23, Month 10, Day 27
3 Dec 1390
The Ministry of Revenue was Imperially commanded to promulgate a strict prohibition against people having contact with foreign fan. As, for ages past, it had not been permitted to pass China's gold, silver, bronze, cash, silks and weapons to the fan and, because at this time in Guang-dong/Guang-xi, Zhe-jiang and Fu-jian, there were foolish people who did not know of this and frequently engaged in private trade with foreign fan, the Emperor ordered that a strict prohibition be implemented. Any military or civilian official along the coast who allowed private trade was to be punished for his crime.
Zhong-yang Yan-jiu yuan Ming Shi-lu, volume 7, page 3067