The right of the third person which has come into existence in accordance with the provisions of Article 539, shall not be altered or extinguished by the parties.
Civil Act — Article 541 (Establishment of third person's right)
민법 제541조
For AI agents and developers — get this article as JSON, with the English and current Korean effective dates and an outdated-translation flag, from the korea-law API or as an MCP tool:
https://mcp.apify.com?tools=kr-data/korea-law