Output Caching doesnt seem to work when its location set to client or downstream

I created 5 .aspx pages with Response.Write(DateTime.Now.ToString()); in the Page_Load event handler, and with <%@ OutputCache Duration="300" Location="Any" VaryByParam="none" %> added after the @ page directive with different versions of location. When i refreshed the page, client and downstream locationed ones refreshed the time as well, this proves that output caching with these two location doesn't cache the page output. The best and robust solution will be setting the location attribute to "any".