Danish krone
Currently, the Danish krone circulates in Greenland. The Greenland krone was not intended to be an independent currency but a version of the Danish krone. Consequently, it was not intended to have its own ISO 4217 currency code, but to use the same ISO 4217 code as the Danish krone, which is DKK. Even if the currency had been adopted, the (regular) Danish krone would have continued to circulate separately.