Currently the only privacy setting for lists are Only Me, Friends on Giftwhale, or Public. This makes it impossible to create lists that are only viewable to a limited group of people. I have lists I want to share with only my partner, but do not want visible by others, and currently the only way to do that is to only accept friend requests from her and no-one else. This is pretty limiting for other collaboration.
There should be a fourth option, "Invite-Only," which either requires a password to access or allows users to select a subset of friends who have access. This way I can comfortably retain the ability to request gifts from certain people and hide those requests from others.