React Guideline: Events — Use synthetic events correctly. Description: React normalizes events across browsers. Do: e.preventDefault() e.stopPropagation(). Don't: Access native event unnecessarily. Good Example: onClick={(e) => e.preventDefault()}. Bad Example: onClick={(e) => e.nativeEvent.preventDefault()}. Severity: Low. Docs: https://react.dev/reference/react-dom/components/common#react-event-object.