North Korean directive means there can only be one Kim Jong-un

A year before North Korean leader Kim Jong-un came to power, a directive was issued for anyone sharing his name to change it - maintaining a tradition upheld by the state's ruling Kim dynasty, a report said.

An internal state document obtained by South Korea's KBS TV station contains an "administrative order" from then leader Kim Jong-il for all party, army and police officials to ensure the directive was carried out.

The order was issued in January, 2011, shortly after Kim Jong-un had been effectively anointed as his father's successor. Kim Jong-il died in December of the same year.

"All party organs and public security authorities should make a list of residents named Kim Jong-un ... and train them to voluntarily change their names," said the document, extracts of which were aired by KBS.

The process involved revising names on official documents, including social security cards and school diplomas. Officials were also directed to reject birth certificates for any newborns named Kim Jong-un.

The directive's authenticity could not be verified but one Seoul official said the regime was known to have banned citizens sharing the names of the two previous Kim generations.