Whats Wrong With the Current Expiration Schemes?
Internet Explorer 5 uses a new mechanism to determine whether to reload data. When it sees a cached object that includes an EXPIRES header, Internet Explorer 5 will use this information to determine whether to contact the server. If the expiration date is in the future, the object will be retrieved from cache and the server will not be contacted at all. As a result, any sites that use the EXPIRES header will afford their clients a noticeable performance gain. You can set EXPIRES either on the server or by using a tag. If you set it on the server, you can specify different expiration values for different objects on the Web page. For example, using ASP, you can set Response.Expires to a negative number to turn off buffering or set it to some other value to specify buffering. This means that you could set a particular object on the site (such as the link of the week) to expire within a week, while the stock ticker object could expire immediately (for immediate refresh).
