If you've been into website development, and in particular website optimization, you probably have stumbled upon that question at least once: what HTTP headers do the different browsers send when the user presses F5 or (even better) CTRL+F5, to make the web server bypass the cache system?
Well, the user "some" on Stackoverflow answered that in a very complete way here: http://stackoverflow.com/questions/385367/what-requests-do-browsers-f5-and-ctrl-f5-refreshes-generate/385491#385491