If there is a custom which differs from any provisions of statutes which are not concerned with good morals or other social order, and if the intention of the parties to a juristic act is not clear, such custom shall prevail.
Civil Act — Article 106 (De facto custom)
민법 제106조
For AI agents and developers — get this article as JSON, with the English and current Korean effective dates and an outdated-translation flag, from the korea-law API or as an MCP tool: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