The 203 (Non-Authoritative Information) status code indicates that the request was successful but the enclosed content has been modified from that of the origin server's 200 (OK) response by a transforming proxy. This status code allows the proxy to notify recipients when a transformation has been applied, since that knowledge might impact later decisions regarding the content. For example, future cache validation requests for the content might only be applicable along the same request path (through the same proxies)