Most WWW browsers will cache or keep a local copy of your pages to speed-up future viewing of those pages. Depending on how a browser is setup, it might display a cached out-of-date version of your pages, specially if you update your pages often. To help browsers decide how long a cached copy of your pages should be in use before retrieving a newer copy from the original web site, you could use following HTML tags:
Above META tags should be placed in between your
and tags. Also note that the specified date should be a date in the past so that the browser will immediately discard the cached copy or not cache it at all.
Although "Expires" tag is properly handled by most browsers, some older browsers may still look for the "no-cache" tag. If you're not worried about users with old browsers, using the "Expires" tag alone is sufficient and will make it possible to specify the exact time to expire content.
