Terminology

Setting Purpose Default Value
ISO Code The 3-digit code that defines what country to apply to the settings. USA
Active Enables or disables the address validation for the country. Yes
RFC Destination The RFC (Remote Function Call) destination set up for Address Validation.
Prompt Set Type Tells the Validation API what input data to expect for searching Default
Flatten Defines whether the search results will be 'flattened' to a single picklist of deliverable results, or shown as (potentially multiple) hierarchical picklists of results that can be stepped into True