diff --git a/README.md b/README.md
index 5bf29570..277f2408 100644
--- a/README.md
+++ b/README.md
@@ -511,6 +511,13 @@ rm -rf node_modules && pnpm install
    - Avoid 'V2' suffixes in service names
    - Verify API integration against official documentation
 
+## Codebase Coding Standard
+
+1. Have types and validation in the shared domain layer.
+2. Keep business logic out of the frontend; use services and APIs instead.
+3. Reuse existing types and functions; extend them when additional behavior is needed.
+4. Follow the established folder structures documented in `docs/STRUCTURE.md`.
+
 ## Documentation
 
 📚 **[Complete Documentation](docs/README.md)** - Full documentation index