shippableCountries stores a list of countries a product may be shipped to while nonShippableCountries stores a list of countries a product may not be shipped to. Use the shippableCountries property in those instances where it is more efficient to list a small number of countries to which a product may be shipped. By contrast, use nonShippableCountries when it is more efficient to list a small number of countries to which a product may not be shipped. Both properties take a value that is a comma-separated list of two-letter, upper-case country codes, as defined by ISO 3166.

The /atg/store/droplet/ShippingRestrictionsDroplet servlet bean, which is used by a number of Commerce Reference Store gadgets, considers both properties when determining if a shipping address is valid for a particular item:

Commerce Reference Store sets the shippableCountries property for all three sites to include US, CA, MX, and DE.