When someone adds you to their Restricted list on Facebook, you will only be able to see their public posts and profile information. You will not be notified if you have been added to someones Restricted list, and you will still be friends with them on Facebook. However, you will not be able to see their private posts, and they will not know that they have been added to your Restricted list. If you want to add someone to your Restricted list, you can do so by going to their profile, selecting Friends > Edit Friend Lists > Restricted.