Rare books in ancient books refer to.

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 Also refers to the loss of the only unpublished manuscript or original, and the only remaining rubbings.

Rare books first refer to ancient books with rigorous collation and exquisite carving, and then their meaning gradually expands to include all kinds of ancient books with earlier carving and less circulation. In fact, real rare books should focus on the contents of books, the scientific research value of ancient books and the value of historical relics.