The <arrival> tag supports an optional redirect attribute.

If this is present, RIFE will redirect the user to the URL of the target element of the arrival. If that element hasn't got an URL, RIFE will simply check whether the arrival element's URL ends with a slash. If that's not the case, RIFE will redirect to that one.

This feature makes it much easier to work with relative paths for resources like images, CSS files and JavaScripts since you can ensure that the entire subsite always has the same URL prefix that includes a final slash.