An interesting article about displaying what a link will do when you click on it. By adding a stylesheet on your browser you can visualize on each link what will happen.
Applying these rules will of course affect the way many websites look, and may occasionally cause minor layout problems. Links that already alert the user that they will open in a new window or point to a non-HTML document will also be affected, so the information will be repeated.
source 456bereastreet.com