Cache-Control: max-age=86400The number is the # of seconds to cache (24 hours in this case). If you're using a Java server like Tomcat you will not get cache-control automatically, but you can do it with a servlet filter. If you're using Apache httpd then you can just turn on a configuration directive. WARNING: If anything else on the server is setting the "no-cache" directive, then you may end up with a response header like this:
Cache-Control: max-age=86400, no-cacheThat header says "cache me for 24 hours, but actually, don't cache me after all." So IE will panic and simply not cache it. To verify you're getting the right cache-control header, inspect the response headers using Fiddler Tool in IE (fiddlertool.com) or the livehttpheaders extension in Firefox.