The person who associated a work with this deed has dedicated the work to the public domain by waiving all of their rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.
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According to Articles 39 to 44 of the Copyright Act of the Republic of Korea, under the jurisdiction of the Government of the Republic of Korea all copyrighted works enter the public domain 70 years after the death of the creator (there being multiple creators, the creator who dies last) or 70 years after publication when made public in the name of an organization. (30 years for death before 1957, 50 years before July 2013)
This applies to copyrighted works of which authors died before 1 January 1963, or made public in the name of an organization before 1 January 1963.
Furthermore, with the exceptions of photographs reproducing otherwise copyrighted works of art, and photographs inserted into a work of study or art and produced only for the purpose of inclusion within said work, photographs or other works of a similar form to photography either published or produced in negative on or before 31 December 1976 are now in the public domain in the Republic of Korea as their term of copyright has expired there.
There are exceptional cases. Property rights are to belong to the state according to provisions of the Civil Law and other laws upon the death of a copyright owner without heir or, in the case of a legal person or organization, upon its dissolution. The product must also be in the public domain in the United States.