The NCL collection comprises over 2,600 archaic contracts, both private and official, dating from 1732 to the early 20th century. Included are contracts established between Han Chinese parties for sales transactions, loans, adoption and other purposes. There is also a large number of deeds signed between indigenous peoples from various parts of Taiwan, as well as contracts concerning some of the larger Han clans in Taiwan.

The NCL has digitally converted all of the archaic contracts in its collection. This data has been annotated and compiled into a database, providing an invaluable resource for research on daily life and economic development in Taiwan from the 18th to19th century.