Status: 302 Temporarily moved Location: http://some.org/new-URL.htmlor
Status: 301 Permanently moved Location: http://some.org/new-URL.html
Example HTTP 1.1 headers
Cache-Control: must-revalidate Cache-Control: max-age=3600 Cache-Control: no-cacheExample HTTP 1.0 headers
Expires: Tue, 08 Apr 1997 17:20:00 GMT Expires: 0 Pragma: no-cacheNote that dates in the Expires header must be given in the correct format, and that illegal values cause pages to be totally uncacheable, which is unlikely to be what you require (besides being antisocial). Generating an Expires header corresponding to the update interval of the page will give optimal results.
If it is not possible to set the HTTP header, the Expires META tag may be used. This will influence many browsers, but typically not proxy caches.
For Netscape Navigator 3.0,
<meta http-equiv="Expires" content="0">
forces the browser to check the modification date each time the object
is loaded from cache (if unchanged, the server returns status 304). This is
equivalent to setting Navigator Option: Network-Preferences: Cache: Verify-Document= Every-Time.
<meta http-equiv="Pragma" content="no-cache;> causes the object not to be cached at all, chewing up bandwidth by forcing a full GET every time the object is referenced.
At this time, not all browsers or proxy agents support HTTP/1.1 operations. The following headers in a CGI script ought to prevent cacheing where this is required, e.g. in Vancover Webpages time page:
Cache-Control: no-cache Pragma: no-cache Expires: 0
Note: You page being framed may not always be abuse. For instance, anther site may include a link to yours but forget to put "target=_parent", or a search engine may use frames. An abusive situation would be where your page, designed to be viewed in your frameset with your navigation data and advertising, is framed by someone else with their own nav./advertising, thus appearing to take credit for your page. Destroying the original frameset of a search engine or legitimate referrer may annoy the user and dissuade them from visiting your site; it may be better to politely suggest that they middle-click or otherwise to view your site in a new window.