Many Korean surnames, when Cyrillized, are spelled and pronounced slightly differently from the romanisations used in the U.S. and the resulting common pronunciations, as can be seen in the table at right. Some surnames of Koryo-saram have a particle "gai" added to them, such as Kogai or Nogai. The origin of this is unclear. The introduction of international passports by newly independent CIS countries, resulted in further differences in pronunciation as Korean surnames had to be transliterated from Cyrillic into Latin. In addition to a surname, Koreans also use clan names (known as Bon-gwan in Korea and pronounced as пой among Koryo-saram) denoting the place of origin.