1. Firearms, ammunition, explosives, and certain weapons
2. Counterfeit or pirated goods, including counterfeit currency
3. Narcotic drugs and psychotropic substances
4. Endangered species and their products, as per the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)
5. Food and agricultural products that require quarantine, such as fresh fruits, vegetables, meats, and live animals
6. Medicines, pharmaceuticals, and medical devices that require approval from the Ministry of Food and Drug Safety (MFDS)
7. Hazardous materials, such as chemicals, pesticides, and radioactive substances
8. Items that infringe on intellectual property rights, such as copyrighted works, trademarks, and patents
9. Cultural assets and artifacts that require approval from the Cultural Heritage Administration (CHA)
10. Items that violate public morals or social order, such as obscene or pornographic materials
11. Items that are prohibited under international sanctions or trade agreements
It's important to note that the exact regulations and documentation requirements may vary depending on the specific item and the purpose of importation. It is advisable to consult with the Korea Customs Service or seek advice from a customs broker to ensure that all necessary documentation is obtained and the importation process is compliant with the applicable regulations.