Sources: Numbers provided by National Library of China/China Daily

When President Xi Jinping talked with US President Donald Trump at the Palace Museum, or Forbidden City, in Beijing on Nov 8, Xi highlighted that "China has 3,000 years of history using written characters" to his visiting US counterpart.

The earliest-known Chinese characters that Xi was referring to, were found inscribed on oracle bones, mainly turtle shell and ox scapula, and were used for the purpose of recording or fortunetelling during the Shang Dynasty (c. 16th to 11th century BC).

The inscriptions were listed in the UNESCO Memory of the World Register program in late November.

"It's a milestone to get the gist of traditional Chinese culture understood and promoted in the world," Du Yue, a director from the National Commission of China for UNESCO, says. "Now, it has become a common spiritual treasure for humanity."

"Oracle bone inscriptions have the same lineage as the writing system used today, and are the ancestors of Chinese characters," says Song Zhenhao, a historian and academician committee member from the Chinese Academy of Social Sciences. He was the principal academic leading the bid to get the oracle bones listed in the UNESCO register.