The small circle on the new version of RMB is a "mark" or "signature" detected by computer, which plays a great role in preventing counterfeit banknotes.

1. All the new banknotes in the world use an imperceptible mark, which is the five rings shown below:

2. The five rings are arranged according to Orion, which was first found on 10 euro (EUR) paper money, so this symbol was named "EUR constellation". Once the machine finds that the picture to be printed contains this mark, it will immediately refuse to print. This sign has played a great role in preventing counterfeit money all over the world.