The policy of the US Government regarding the name Sea of Japan

The US Board on Geographic Names is a US governmental organization established in 1947 to standardize the geographic names used in government publications. The policy of naming determined by the Board is binding upon all the federal governmental agencies, including the Department of State. All publications issued by such agencies must therefore comply with the policy. It is also strongly recommended that other organizations in the US comply with the policy determined by the Board.
The US Board on Geographic Names officially published their determination that the name Sea of Japan is the only officially recognized name for the sea area concerned. This means that all the US federal governmental agencies are required to use the name Sea of Japan, and that other organizations in the US are strongly recommended to use it.