Towards the end of the Yuan Dynasty, Zhang Shicheng, the leader of the anti-Yuan uprising in Taizhou, Jiangsu Province (or Liu Bowen, the strategist of Zhu Yuanzhang), took advantage of the Mid-Autumn Festival to give each other round cakes to bring a note of "killing Tartars on the night of the 15th of the 8th month" in the cakes. "Tartars" (Yuan soldiers), after the family ate cakes to celebrate the victory of the uprising, and officially called the Mid-Autumn Festival round cake for the moon cake.
For a long time later in history, even at the end of the last century, many mooncakes were still labeled with a small piece of paper on one side! Unfortunately, in recent years, the production of moon cakes have disappeared small pieces of paper, moon cakes contained in the "cultural code" passed from generation to generation disappeared.