What requests do browsers' “F5” and “Ctrl + F5” refreshes generate?

Question

Is there a standard for what actions F5 and Ctrl + F5 trigger in web browsers?

I once did experiment in IE6 and Firefox 2.x. The F5

Answer 1

At least in Firefox (v3.5), cache seems to be disabled rather than simply cleared. If there are multiple instances of the same image on a page, it will be transferred multiple times. That is also the case for img tags that are added subsequently via Ajax/JavaScript.

So in case you're wondering why the browser keeps downloading the same little icon a few hundred times on your auto-refresh Ajax site, it's because you initially loaded the page using CTRL-F5.