Proxy Web Servers and Authentication > How Proxies Work > Cache headers

General

Headers that can be used in either HTTP Requests or Responses.

Date

Date and time the message was created. Format of the field must be as described in RFC1123 (e.g. "Tue, 15 Nov 1994 08:12:31 GMT").

Pragma

Used to pass special directives in request and response messages. One commonly used Pragma header is "no-cache", but this is being phased out in favor of the "Cache-control" header.

Via

Indicates the chain of proxy servers used to forward the message. Proxy servers must specify the protocol/version and the hostname or pseudonym of the server.