The OrganizationUnitSet is still being used, cannot delete.
The OrganizationUnitSetScope is still being used, cannot delete.
Set {0:string} is a set managed by EVA and cannot be modified.
It's not possible to use an AdHoc set as a subset of another set.
Name is required when creating a non-AdHoc set.
It's not possible to use OrganizationUnitSetTypes.System to create new sets.