http-stats:
HTTP/1.1 X-Cache header field

The X-Cache field is NOT a standard HTTP header field and may not be supported by all clients.

Common X-Cache header values:

The non-standard "X-Cache" header is only sent by:

NOTE: this header may be sent directly by the server software or from some third party application running on that server.

Sample X-Cache web server response:

HTTP/1.1 200 OK
Content-Type: text/html; charset=UTF-8
Content-Length: 5607
X-Cache: MISS from 167-217.tudou.com
Date: Fri, 30 Jul 2010 16:59:34 +0000

<!DOCTYPE html PUBLIC "-//W3C//DTD ...
...
...

Other common HTTP headers

Other less common headers