What does this kind of http header mean in symfony?

$this->getResponse()->addCacheControlHttpHeader('private=True');

What's 开发者_StackOverflowthat for,how does it work?

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http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9.1

private:

Indicates that all or part of the response message is intended for a single user and MUST NOT be cached by a shared cache. This allows an origin server to state that the specified parts of the response are intended for only one user and are not a valid response for requests by other users. A private (non-shared) cache MAY cache the response. Note: This usage of the word private only controls where the response may be cached, and cannot ensure the privacy of the message content.

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It's related with the cache control directive.

By default, pages protected with HTTP authentication are considered private; they will not be kept by shared caches. However, you can make authenticated pages public with a Cache-Control: public header; HTTP 1.1-compliant caches will then allow them to be cached.