The full form of DK is Denmark. It’s used on Regional ,Countries in Denmark

Denmark , officially the Kingdom of Denmark, is a Nordic country in Northern Europe. Denmark proper, which is the southernmost of the Scandinavian countries, consists of a peninsula, Jutland, and an archipelago of 443 named islands, with the largest being Zealand, Funen and the North Jutlandic Island.

The etymology of the name “Denmark”, the relationship between “Danes” and “Denmark”, and the emergence of Denmark as a unified kingdom are topics of continuous scholarly debate. This is centered primarily on the prefix “Dan” and whether it refers to the Dani or a historical person Dan and the exact meaning of the –“mark” ending.

Most etymological dictionaries and handbooks derive “Dan” from a word meaning “flat land”,related to German Tenne “threshing floor”, English den “cave”. The element mark is believed to mean woodland or borderland (see marches), with probable references to the border forests in south Schleswig.

The first recorded use of the word Danmark within Denmark itself is found on the two Jelling stones, which are runestones believed to have been erected by Gorm the Old (c. 955) and Harald Bluetooth (c. 965). The larger of the two stones is popularly cited as the “baptismal certificate” (dåbsattest) of Denmark, though both use the word “Denmark”, in the accusative ᛏᛅᚾᛘᛅᚢᚱᚴ tanmaurk ([danmɒrk]) on the large stone, and the genitive ᛏᛅᚾᛘᛅᚱᚴᛅᚱ “tanmarkar” (pronounced [danmarkaɽ]) on the small stone, The inhabitants of Denmark are there called tani ([danɪ]), or “Danes”, in the accusative.