HTTP Caching HTTP responses Obsolete, redundant and non-standard headers
Example
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Expires— specifies date when the resource becomes stale. It relies on servers and clients having accurate clocks and supporting time zones correctly.Cache-control: max-agetakes precedence overExpires, and is generally more reliable. -
post-checkandpre-checkdirectives are non-standard Internet Explorer extensions that enable use of stale responses. The standard alternative isstale-while-revalidate. -
Pragma: no-cache— obsoleted in 1999.Cache-controlshould be used instead.
