cache control http header response directive which makes a resource cacheable by any cache code example

Example: Cache-Control: no-cache, no-store Expires: 0 Pragma: no-cache

header("Cache-Control: no-cache, no-store, must-revalidate"); // HTTP 1.1.
header("Pragma: no-cache"); // HTTP 1.0.
header("Expires: 0"); // Proxies.