The second set of Chinese currency, the unnumbered paper fractional notes, after more than 20 years of issuance and circulation, has seen a rich and colorful evolution in its serial lettering (prefixes), which can be divided into three-letter and two-letter forms, as well as having distinctions between large and small fonts. Summarizing, it possesses the following characteristics:
1. Unique and innovative prefix forms
The prefixes serve functions such as controlling print quantities, anti-counterfeiting, and indicating issuance status. In today's world, among all countries' banknotes, except for some fractional currencies that lack prefixes and numbers (such as Hong Kong Government's one-cent note), the vast majority have both prefixes and numbers, or sometimes only numbers without prefixes. Prefixes come in various forms, including one-character, two-character, three-character, and four-character prefixes. China’s unnumbered paper fractional notes adopt a unique form with prefixes but no numbers. In fact, these prefixes are also numbers, not the commonly used Arabic numerals, but Roman numerals, utilizing ten ancient Roman counting symbols recombined according to traditional Chinese habits to be used as prefixes on the fractional notes. Roman numerals Ⅰ, Ⅱ, Ⅲ, Ⅳ, Ⅴ, Ⅵ, Ⅶ, Ⅷ, Ⅸ, Ⅹ correspond to Arabic numerals 1, 2, 3, 4, 5, 6, 7, 8, 9, 0. It must be noted that the Roman numeral Ⅹ does not represent 10, but rather 0, which is very important because it relates to the arrangement order of the prefixes. This is an example of using ancient methods for modern purposes and adapting foreign elements for Chinese use.
2. Formation of rules in prefix arrangement
In banknotes from all over the world, if there are prefixes and numbers, each note will have a unique number, and under the same prefix, there won't be repeated numbers. For the unnumbered paper fractional notes, since they only have prefixes and no numbers, and the prefixes control the print quantity, many types of prefixes are compiled, resulting in multiple notes sharing one type of prefix, each batch having one number, with numerous repeated numbers. Renminbi paper fractional notes have two types of prefixes: three-digit (commonly known as three-character prefix) and two-digit (commonly known as two-character prefix). The three-character prefix was issued first. The 1-fen note has both three-character and two-character prefixes, while the 2-fen and 5-fen notes only have three-character prefixes. The three-character prefix follows three basic rules: First, among the three numbers, there must be two that are the same, such as: ⅣⅣⅩ, ⅣⅩⅣ, ⅩⅣⅣ, all have two identical Ⅳs and one different Ⅹ; Second, there are no cases where all three numbers are the same, for example: ⅡⅡⅡ; Third, there are no cases where all three numbers are different, like ⅤⅥⅦ. The two-character prefix is arranged in ascending power order starting from ⅩⅩ.
According to some statistics, there should be 524 types of prefixes for the unnumbered paper fractional notes, and currently, 518 types have been discovered, including 328 types for the 1-fen note (234 types of three-character prefixes and 94 types of two-character prefixes), 129 types for the 2-fen note, and 61 types for the 5-fen note. To enrich the varieties of Renminbi collections, a new type of 1-fen, 2-fen, and 5-fen notes with the prefix ⅠⅡⅢ has been issued recently, available in single sheets and continuous sheets, mostly issued in framed form. The arrangement of the prefixes for these notes is completely different from the aforementioned ones, and the font of the prefixes is also quite special, referred to by some as "computer large number". The value ratio between the 1-fen, 2-fen, and 5-fen notes is 1:2:5, and their prefix quantity ratio should be inverted to 5:2:1, meaning for every 5-fen note printed, two 2-fen notes and five 1-fen notes need to be printed; for every type of prefix on a 5-fen note, two types of prefixes on 2-fen notes and five types of prefixes on 1-fen notes need to be printed. That is to say, comparing the number of banknotes and the variety of prefixes, the 5-fen note is less than the 2-fen note, and the 2-fen note is less than the 1-fen note, which aligns with the physical specimens and prefix varieties that have been discovered.
On August 31, 2006, the People's Bank of China announced in its 10th announcement that it would stop the circulation of the second set of Renminbi paper fractional notes in the market starting from April 1, 2007. Thus, this group of banknotes with the longest circulation time and smallest denomination completed its historical mission.