One part of the question ~ Shift F5
First thing to note is that F5 and Shift-F5 do the same thing, the shift isn't a modifier for the command action. CTRL is though.
So pressing F5 only does anything if the web page was mofified since last viewing.
On FF, IE7, Opera and Chrome.
F5 usually updates the page only if it has been modified at source since the last viewing. The browser usually tries to use all types of cache as much as possible and adds an "If-modified-since" header to the request. Opera differs by sending a "Cache-Control: no-cache".
CTRL-F5 is used to force an update, disregarding any cache. IE7 adds an "Cache-Control: no-cache", as does FF, which also adds "Pragma: no-cache". Chrome does a normal "If-modified-since" and Opera ignores the key.
Netscape which was the first browser to add support for cache-control by adding "Pragma: No-cache" when you pressed CTRL-F5.
One part of the question ~ Shift F5
First thing to note is that F5 and Shift-F5 do the same thing, the shift isn't a modifier for the command action. CTRL is though.
So pressing F5 only does anything if the web page was mofified since last viewing.
On FF, IE7, Opera and Chrome.
F5 usually updates the page only if it has been modified at source since the last viewing. The browser usually tries to use all types of cache as much as possible and adds an "If-modified-since" header to the request. Opera differs by sending a "Cache-Control: no-cache".
CTRL-F5 is used to force an update, disregarding any cache. IE7 adds an "Cache-Control: no-cache", as does FF, which also adds "Pragma: no-cache". Chrome does a normal "If-modified-since" and Opera ignores the key.
Netscape which was the first browser to add support for cache-control by adding "Pragma: No-cache" when you pressed CTRL-F5.