caching behaviour

[Marco Kleefman]

Can anybody point me to a document which describes all the ins and outs of
caching behaviour of internet applications. I know the following has its
influence:
 
http 1.1 protocol
webserver (in my case Apache)
browsersettings (in my case IE 4.0 or higher)
 
My problem is that sometimes the browser displays the wrong picture (picture
from cache), instead of retrieving the latest one. The picture is generated
with a Perl/CGI script.
 
thanx in advance,
 
Marco