It seems to me that there are two common appearances to the dates one can see on the South Korean One-Won coin dated "1968." What is this called? "Date variation?" "Recut date?"
Doesn't really have a name. Just die varieties caused by the date not being on the hub and added to two separate dies in a way that is discernable. There could always be more dies that are identical and you wouldn't know. They would still be additional varieties, but only on paper since they would be indistinguishable.