HTTP status code 203 “Non-Authoritative Information” indicates that the server has successfully processed the request, but the entity headers returned may come from a third party rather than the original server. This status code is primarily used by proxy servers, signaling that the response returned has been modified from the original server’s response.
Specifically, status code 203 indicates that while the information in the response originates from the requested resource, it has been transformed or altered and is no longer the original content provided directly by the origin server. The use of proxy servers is a typical context for this status code, where the proxy acts as an intermediary between the client and the origin server. Proxy servers may cache or modify the returned content to enhance response speed or meet specific requirements.