The following table lists the cache control directives supported by an HTTP client.
|
Directive |
Behavior |
|---|---|
|
no-cache |
Caches cannot use a particular response to satisfy subsequent requests without first revalidating that response with the server. If specific response header fields are specified with this value, the restriction applies only to those header fields within the response. If no response header fields are specified, the restriction applies to the entire response. |
|
no-store |
Caches must not store any part of a response or any part of the request that invoked it. |
|
max-age |
The consumer can accept a response whose age is no greater than the specified time in seconds. |
|
max-stale |
The consumer can accept a response that has exceeded its expiration time. If a value is assigned to max-stale, it represents the number of seconds beyond the expiration time of a response up to which the consumer can still accept that response. If no value is assigned, it means the consumer can accept a stale response of any age. |
|
min-fresh |
The consumer wants a response that will be still be fresh for at least the specified number of seconds indicated. |
|
no-transform |
Caches must not modify media type or location of the content in a response between a provider and a consumer. |
|
only-if-cached |
Caches should return only responses that are currently stored in the cache, and not responses that need to be reloaded or revalidated. |
|
cache-extension |
Specifies additional extensions to the other cache directives. Extensions might be informational or behavioral. An extended directive is specified in the context of a standard directive, so that applications not understanding the extended directive can at least adhere to the behavior mandated by the standard directive. |