The inscription is in regular (kai) script and is believed to be the calligraphy of the emperor himself. The coin has a broad margin and is finely cast. It was cast during the reign of the Northern Song emperor Qinzong but, owing to the emperor being on a campaign to the northern regions for 16 months of the Jing kang period, the number of coins cast during this reign period was very small, and the subset of Jing kang tong bao coins even fewer. Hence, because of the shortness of the reign period, the small number of coins cast and the differences between the moulds, this is an extremely rare and precious piece. This already brief reign period was subdivided into periods of different lengths, the calligraphic style of the time was changeable, and coins were produced in both copper and iron in several denominations, including one-, two- and three-cash, producing very distinctive coins. (Wang Yuanxue)