3. in a foreign country, any diplomatic or consular agent or representative of the United States, appointed or accredited to, and residing within, the country, or a person appointed by commission or under letters rogatory, or an officer of the armed forces authorized to take the acknowledgment of deeds.
Officers may be designated in notices or commissions either by name or descriptive title and letters rogatory may be addressed "To the Appropriate Authority in (here name the state or country)."