Choose whether other people may add you to their friends list. If you are added to a friends list, the owner of that list is added to your list as well. When you remove someone from your friends list, you are also removed from their list. Choose either:
Nobody may add me as a friend: no one may add you to their list.
New friends require my authorisation: your authorisation is needed for you to be added to a list. If you approve, they will be added to your list.
New friends are automatically authorised: anyone may add you to their list.