What are the common JSON RPC error codes and what do they mean?

JSON RPC uses error codes to categorize failures. Some common ones include: `200` (Success), `400` (Bad Request – invalid request), `401` (Unauthorized – authentication failed), `403` (Forbidden – insufficient permissions), `404` (Not Found – method or resource not found), `500` (Internal Server Error – server-side problem), and `503` (Service Unavailable – server temporarily unavailable). Consult the specific service's documentation for a complete list and detailed explanations of each error code.