Da Guan Tong Bao -
Mongol 2 cash coin

Diameter: 28.7 mm
Weight: 6.1 g

        By some opinions shown coin was issued during the Yuan dynasty. It is presented in the Ding's catalog (Northern Song section), D1057 and in the catalog 'Coins in the collection of the Shanghai Museum. Coins of the Song, Liao, Jin and Western Xia dynasties.', Shanghai, 1994 - coin number 1377, weight 4.3 g. In the modern catalogs, for example in the 'Illustrated plates of ancient Chinese coins', this variety is missed.

       Orlando Tsai in his book placed the larger example of Yuan dynasty Da Guan Tong Bao (40 mm) with two characters Pan and Ch'ie on the reverse (Tsai N468, also Ding N1064). Coin referred to Emperor Shih Tsu (Kublai Khan) who ruled in the period 1260-1294 AD.

        Gilbert Tan, 02-Dec-2000:

Da Guan coins were issued also by both Jin Dynasty and Yuan Dynasty. Some were issued as charms with various marks on the reverse but others were simply unusual calligraphy.
Reason for issue of unusual calligraphy is not known. But a good guess would be that they simply liked the writing and decided to make some coins!