Development of the banknote began in the Tang Dynasty during the 7th century, with local issues of paper currency, although true paper money did not appear until the 11th century, during the Song Dynasty.
A contract typically does not have to be notarized. A notary public (or simply notary) provides an acknowledgment that the signature appearing on the document is that of the person whose signature it purports to be. There is a requirement that some documents be notarized, such as a real property deed.
In most cases of property transfers, both the seller and buyer will be required to sign three copies of the property deed while in the presence of a notary public as well as one other witness (note: the notary may act as one of the witnesses).