[7][8] In some cases the usage of certain types of materials to produce cash coins are only more recently discovered due to the lack of historical records mentioning them.

[16] This was a good method to balance imports and exports because foreign tradesmen and merchants could not use the iron and lead cash coins they received as payment in other states, forcing them to spend them locally before they left.

[17] While the southern kingdoms often issued iron and lead cash coins, many regimes in the central plains explicitly forbade their circulation.

[13] For example, the Later Tang ordered all iron and lead cash coins within its territory to be collected and destroyed as it saw their circulation as an invitation for counterfeiters to deliberately produce cheap and bad quality money that would negatively affect the economy.

[22] Bronze cash coins with this same inscription dated to this period are sometimes attributed to have been produced during the reign of King Wumu, but their usage may have been as funerary items rather than as circulation currency.

[23] The Southern Tang Kingdom issued a lead version of the Tangguo Tongbao (唐國通寳), an inscription which was also used for bronze and iron cash coins.

[28] The "Yong" (邕) on the reverse side of these Qianheng Zhongbao cash coins is believed to mean that they were minted in Yongzhou, today's Nanning and its vicinity in Guangxi.

[13] Other Qianheng Zhongbao cash coins have the character "Yi" (邑) on their reverse sides, which is said to refer to the capital city, what is today Guangzhou.

[13] Wang Guizhen (王贵枕), a Guangdong numismatist, believes that Qianheng Zhongbao lead cash coins with the "Yi" character on their back may have been for the exclusive for Cantonese people prohibiting them from circulating outside of the city.

[13] Wang Yinjia (王蔭嘉 / 王荫嘉), a numismatist during the early Republic of China period, believed that "the economic policy of the Southern Han dynasty is bizarre and inexplicable", stating that "the lead cash coins in the city [Guangzhou] cannot go out of the city gate, disallowing the people from purchasing things outside, how can the public and private trade work?

"[13] Wang Yinjia asked these questions to fellow numismatist Luo Bozhao (羅伯昭 / 罗伯昭), who wrote "The History of Money in the Southern Han Dynasty" (南漢錢史) in response.

[13] This may be the result of their deliberate destruction at the hands of Liu Yan who regarded the Later Liang as a "puppet court" (偽廷) and sought to erase it from history beginning with the eradication of the lead Kaiping Yuanbao cash coins.

[13] Another interesting phenomenon is that Kaiping Yuanbao lead cash coins, which are rarely found in China, are often unearthed in Palembang, Indonesia.

[13] During the Five Dynasties and Ten Kingdoms period a number of small, poorly made, illiterately written lead cash coins circulated in the Southern Han and Chu area.

[30] These crude lead coins exhibit a great variety due to the incompetence of the workmen, in some instances the character "Kai" (開), as in "Kaiyuan Tongbao", appears to be a "Yong" (用).

[30] Until relatively recently, it was not known that the imperial government of the Song dynasty had attempted several times to create lead cash coins.

[31] Pan stated that these characteristics all indicate that this was an official casting and after comparative analysis by a number of other experts in the field it was concluded that this previously unknown lead cash coin is indeed undoubtedly genuine.

[37] Following the establishment of the central government Minting Bureau to issue its own holy currency the lead cash coins were recalled to be melted down.

[37] According to insiders of the soy sauce making industry, the companies that operated the Shengji (生記) and Hengji (亨記) soy bean gardens had a large business scope during the Qing dynasty period and were also in the business of producing wine, wheat, beans, and rice, to do this they produced utensils made out of tin and lead.

[37] The book "Historical Currency of Vietnam" (越南歷史貨幣) claims that after the war with the Yuan dynasty (Mongol Empire), the supply of copper in Đại Việt was insufficient.

[13] There is a lead cash coin with the inscription Thiên Minh Thông Bảo (天明通寳) produced in the Quảng Nam province.

[46] There were no laws that regulated the different standards of copper, zinc, and lead cash coins and their value was completely dependent on what market decided.

[46] There were 2 versions of the lead Gia Long Thông Bảo cash coin, one with a plain reverse and one with the characters Thất phần (七分).

[45] Toda attributed 2 lead cash coins to the reign of the Tự Đức Emperor, one was a small size one that also made in zinc and copper and another one with the characters Hà Nội (河內) on its reverse side, indicating its place of production.

[45] Toda reported that during the Lê Văn Khôi revolt, the rebel forces under Lê Văn Khôi produced lead cash coins with the inscription Trị Nguyên Thông Bảo (治元通寳), these coins featured a crescent and a dot on the right and left of the square central hole on their reverse sides.

[51] These cash coins were either oval or square and had the inscription Ka-nihyaku (價二百) written in regular script, indicating that they had a nominal value of 200 mon.

[56] Furthermore, she noted that the technical reason was because the addition of lead to copper-alloys boosted the fluidity of the melt, which facilitated the manufacturing process and qualitatively helped to improve the result.