- From: Henrik Nordstrom <henrik@henriknordstrom.net>
- Date: Thu, 25 Jun 2009 00:05:56 +0200
- To: Bil Corry <bil@corry.biz>
- Cc: "ietf-http-wg@w3.org" <ietf-http-wg@w3.org>
ons 2009-06-24 klockan 16:32 -0500 skrev Bil Corry: > Is there a resource that gives the "official" way to prevent caching across all browsers and proxies? RFC2616? I think a lot of this headache actually comes from the ignorance mentioned earlier. Site authors don't care, users / network operators gets annoyed and start to bend rules trying to optimize their (or their users) Internet experience, and suddently what should be an easy condition no longer is trivial with multi level operator error to take into account.. RFC2616 rules is simple: Not cached: Expires: Date header or older Cache-Control: no-cache and avoid any cache validator (Last-Modified/ETag) Not cached by proxies but cached in browsers: Expires: Date header or older Cache-Control: private, max-age=NN The Expires requirement is due to HTTP/1.0 legacy. In practice using very old date for Expires is probably better as some cache implementations take the Expires date literally not compensating for clock skew when origin server clock is ahead of the cache clock... (implementation bugs..) Regards Henrik
Received on Wednesday, 24 June 2009 22:06:34 UTC