A 203 status code means that the request was received and understood, and that information sent back about the response is from a third party, rather than the original server. This is virtually identical in meaning to a 200 status code.

The returned metainformation in the entity-header is not the definitive set as available from the origin server, but is gathered from a local or a third-party copy. The set presented MAY be a subset or superset of the original version. For example, including local annotation information about the resource might result in a superset of the metainformation known by the origin server.

This code may be used in place of 200 when the sender has reason to believe the information in the response's entity headers are different than what the origin server would send.