Although the Korean Armistice Agreement specifies where the demarcation line and demilitarized zone are located on land, the agreement does not mention lines or zones in adjacent ocean waters. Shortly after the signing of the Armistice, a line in the sea was drawn unilaterally by the United Nations Command (UNC). This Northern Limit Line or North Limit Line (NLL) represented the northern limit of the area in which South Korea permits its vessels to navigate, not a demarcation line on which the two Koreas agreed. The Korean Armistice Agreement (KAA) provisions regarding the MDL and DMZ do not extend into the Yellow Sea or Sea of Japan.