And for those wondering how to do this with CGI.pm, this seemed to work for me: 
print header({-pragma=>'no-cache'});
print $query->start_html(-title=>'My Florb'',
                         -author=>'web@domain.com',
                         -base=>'true',
                         -meta=>{'keywords'=> 'Palm PDA parser',
                                 'copyright'=> 'Copyright © 2002 
+Florb, Inc.',
                                 'Cache-Control'=>'no-cache',
                                 'robots'=> 'index,follow'},
                        );

[download]
Microsoft has a Support article on this exact topic:
"When you use the <HTTP-EQUIV="PRAGMA" CONTENT="NO-CACHE"> metatag in the header section at the beginning of an HTML Web page, the Web page may still be cached in the Temporary Internet Files folder."
Also:

As of version 1.56, all HTTP headers produced by CGI.pm contain the Pragma: no-cache instruction. However, as of version 1.57, this is turned OFF by default because it causes Netscape 2.0 and higher to produce an annoying warning message every time the ``back'' button is hit. Turn it on again with the method cache().

Here's a smaller test example: 
use CGI qw/:standard/;

$modtime = scalar(gmtime(time - (3600 * 8))) . " GMT";
$exptime = scalar(gmtime) . " GMT";

print header(-expires=>$exptime, 'last-modified'=>$modtime,
             'cache-control'=>"no-cache, must-revalidate",
             'pragma'=>"no-cache"),
start_html('Header Test'),
pre("\nModtime: $modtime\nExptime: $exptime\n"),
end_html;

[download]
HEAD on this will show (among other things): 
200 OK
Cache-Control: no-cache, must-revalidate
Pragma: no-cache
Expires: Fri Jun  7 13:23:22 2002 GMT
Last-Modified: Fri Jun  7 05:23:22 2002 GMT

[download]
RFC 2068 goes over this a bit as well.

The Pragma: no-cache and Expires headers are the important ones for clients which do not understand the Cache-Control header.

In reply to Re: Strange POST Behavior / Possible Caching Issue by hacker
in thread Strange POST Behavior / Possible Caching Issue by vroom

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