Let's say you want to redirect visitors from one subdomain to another. You can do this by putting this in your web.config for the redirected-from application:
<?xml version="1.0" encoding="UTF-8"?>
<httpRedirect enabled="true" destination="https://abc.example.com/newpages" httpResponseStatus="Permanent" />
This is ideal for obsolete website addresses that may still be saved in favorites, or linked to on a corporate intranet, or for redirecting common mistakes, such as users entering www.example.com/webmail when what they really want is mail.example.com/webmail.