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I'd like to set the following:

ExpiresActive On
ExpiresByType application/x-flash-swf  "access plus 1 days"
ExpiresByType application/x-shockwave-flash  "access plus 1 days"
<FilesMatch "\.swf$">
 Header set Cache-Control "public"

but I usually set on html

<embed src="" />

What is the difference YYYYMMDDSS and Expires(mod_expires)?

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What is the difference YYYYMMDDSS and Expires(mod_expires)?

mod_expires sets the headers in the HTTP protocol, and most caching servers which follow the HTTP specs do exactly what you request with the correct headers.

Using a query parameter with a date as part of a URL, and thus the corresponding GET request doesn't set any expiration. You are depending on the browser to operate the way you expect. This is a bit of a hack and is somewhat uncommon, but I suspect it works.

You can do both if you like.

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"YYYYMMDDSS" will not be cached proxy server.

You can manual update user cache, change "YYYYMMDDSS".

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Thank you so much . but only that ? – freddiefujiwra Feb 9 '11 at 8:26
You can manual update user cache, change YYYYMMDDSS. – alvosu Feb 9 '11 at 8:32
I believe I have seen proxy servers cache things with query parameters included as part of the URL in a GET request. – Zoredache Feb 9 '11 at 8:36
By default Squid and other Windows proxy don't cache. – alvosu Feb 9 '11 at 8:41

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