[squid-users] What to do if no expire info received from server

Hi folks,

there's a web-server, that sends no info about caching or expiry of
documents. That is the http header received while fetching a flash applet:

HTTP/1.x 200 OK
Date: Fri, 09 Nov 2007 15:26:46 GMT
Server: Jetty/5.1.x (Mac OS X/10.4.9 i386 java/1.5.0_07
Content-Type: application/x-shockwave-flash
Content-Length: 60749
Last-Modified: Wed, 07 Nov 2007 14:18:36 GMT
Accept-Ranges: bytes

Does this violate the http standard? Is a web-server required to send
infos about document lifetime along with a document?

Thanks for helping me.

-- 
kind regards
Dirk Taggesell