304 Not Modified

Description
The HTTP 304 Not Modified client redirection response
code indicates that there is no need to retransmit the requested resources. It is an
implicit redirection to a cached resource. This happens when the request method is
a safe method, such as GET or HEAD,
or when the request is conditional and uses an If-None-Match or an
If-Modified-Since header.
The response must not contain a body and must include the headers that would
have been sent in an equivalent 200 OK response:
Cache-Control, Content-Location, Date, ETag, Expires, and Vary.