Cache-Control Header SyntaxThe Cache-Control header is broken up into directives. Directives are responsible for cache conditions and duration and may have an optional argument. Multiple directives must be separated by a comma.
Or you may add each directive in a separate line.
An example of a request with 'Cache-Control: no-cache, no-store, must-revalidate' header that requires a fresh version of the resource (prevents caching) and works across all servers and proxies.
Cache-Control Header Examples
The 'no-store' directive applies to both private and shared caches. This directive indicates that no part of the request or response must be stored and the information must be removed as soon as possible after being forwarded.
The 'public' response directive indicates that a resource is available for any cache; that it may be cached by any cache, even if it would normally be non-cacheable or cacheable only within a non-shared cache.
This response can be cached by the client’s browser only for up to 10 minutes (max-age=600). The private response directive indicates that the resource depends on the user - it can still be cached, but only on the client device. For example, a webpage response marked as private may be cached by the browser on the desktop, but not by the content delivery network (CDN).
Specifying 'no-cache' and 'max-age=0' points out the possibility of caching a resource. The stored response must be validated first with the origin server before using it.
When the 'must-revalidate' directive is present in a response the client must revalidate the response after it becomes stale.