Country Code - SITUATION RULE: Required when the address is outside the United States of America. If not required by this implementation guide, do not send.
Source - ISO 3166
What would be the situations (if any) in which it is proper to send a US territory as a country code? The ISO 3166 standards publishes the dependent territories with country codes.
Related RFI #1404 response - According to the United States Postal Service State Abbreviation List, these countries/territories are included as states. As such, they don't require that a country code be sent.
There is no situation in which a territory of the United States would be reported using a country code in N404.
The N404 situational rule states “Required when the address is outside the United States of America. If not required by this implementation guide, do not send.” Territorial addresses are not outside the United States. Therefore, the country code would not be sent