Access Schema Settings in Setup
You can now manage the availability of the list custom settings type
when creating custom settings. The list type provides a reusable set of static data that you
can access across your org. To prevent creating custom settings when using application-level
data definitions, disable this option in Setup.
Available in: Group, Professional, Developer, Enterprise, Performance, Unlimited, and Database.com Editions |

With the option enabled, you can choose List as the setting type when
defining a new custom setting.