Orphan book means that there is only one version of a book circulating in the world. Also refers to the loss of the only unpublished manuscript or original, and the only remaining rubbings. The earliest printed matter in the world-Diamond Sutra Paper printed in China in Tang Dynasty (AD 868) is an orphan. Another example is the novel "After the Water Margin" published by Feng Chun Literature and Art Publishing House in the late Ming and early Qing Dynasties, which is a treasure among the treasures collected and printed by Dalian Library. Because it is extremely rare, its price is one hundred times higher.

The Shanghai Library has Song Tuo's Inscription of Liquan in Ou Yangxun Jiucheng Palace. The extant rubbings of the Song Dynasty are the most precious. In the autumn auction of the tenth anniversary of 20 16, a volume of Song Tuo's "Jiuchenggong Liquan Ming" collected by Gong sold for a sky-high price of172,500 yuan;