The IETF has approved a new HTTP status code 103 today. The code is supposed to "minimize perceived latency." So HTTP responses normally require external sources in the head request for rendering HTML. The hope is to get these request as early as possible to minimize latency. All this happens in the header in pre-load. All this information happens as the header is running through the resources looking for and requesting external sources as well as internal sources such as database stuff. This cannot happen until the status code and the full header fields of the final HTTP responses are determined. Hence the 103, the informational status code. Normally the server will send the header fields in a 103 early session response. Sometimes this does not happen correctly as when the server learns that they are not correct before a final response is sent off. The header fields only provide hints to the clients, the process does not replace header fields. On another note the 103 response cannot affect how the final response is processed. Therefore the client cannot interpret a 103 response as if they were applied to the informational response itself. i.e the metadata
