6.1.2 City and country identifiers
City and country values are derived from the source data wherever possible. There may be multiple possible cities or countries associated with an individual, perhaps because an individual resides in more than one country, has dual nationality, or resides in a different country from his/her nationality.
Country values are prepared as a space-separated list of two-character
country codes in the dnAllCountryCodes attribute.
City values (which may contain spaces, for example, ‘New York’) are
prepared as a pipe-separated list of cities in the dnCity
attribute.