A collection of royal protocols from the Joseon Dynasty called "Uigwe" have been designated as a state treasure.

Seoul's Cultural Heritage Administration said Tuesday that the royal protocols which depict procedures of various Joseon era ceremonies in writing and pictures were classified as a cultural treasure.

The Uigwe royal protocols comprise one-thousand-757 items consisting of two-thousand-751 books. They include manuscripts of records that were meant to be viewed by the king. Some were stored in provincial areas while records of other storage locations have not been confirmed.

The historical books were returned to South Korea in late 2011, some 90 years after the Japanese Government General of Korea took them to Japan during the colonial period.