On Facebook, I occasionally see certain friends with their privacy settings set to Custom. When I comment on their posts, I don't want my comments to show up publicly, but I can't know whether they will for sure because the Custom privacy setting is all that's shown.
From experimenting myself, it doesn't seem possible to set the Custom privacy setting to include the public, although I suppose there is always a possibility with Facebook's increasing tendency to test new features differently across regions.
Can the Custom privacy setting ever include the public, or will Friends of Friends always be as public as it gets?