This link is a "shared" link between the Header, Footer and Sidebox.
The number on the order was set to 50 on all of the settings just for the sake of an easier notation on entering it.
The order can be the same or different for the three locations.
If you wanted to really get creative, you could also have this as part of a Chapter not related to the link order.
Your IP Address is: 220.127.116.11