Cache control. Allows selectively disabling client-side caching (browser, proxy servers, network caching systems) and caching in the internal Platform Server cache.

cache= *cacheControl*

cache= *clientControl*, *serverControl*


on | off | validate


on | off


on | off

If only one cacheControl value is specified, it is applied to both client and server caches.

The ’ validate’ keyword allows updating server cache entries after texture or vignette files have changed, without having to wait for the cache entry to expire automatically. Client caching is not affected by this command.

If specified in a nested request, cache=on enables persistent, server-side caching of the image generated by the nested request. Care should be taken to enable caching for nested requests only when the same nested request is expected to be called repeatedly with exactly the same parameters.


May occur anywhere in the request. Ignored when the request does not return a reply image. clientControl is ignored when client-side caching is disabled by the material catalog (if attribute::Expiration has a negative value). serverControl is ignored if server caching is disabled ( PlatformServer::cache.enable).


cache=on,on for HTTP requests, cache=off for nested/embedded requests.

See also

catalog::Expiration, req=

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