According to IHO (International Hydrographic Organization) Technical Resolution A.4.2.6 (1974), it is recommended that when two or more countries share a given geographical feature (such as, for example, a bay, channel or archipelago) under a different name form, they should endeavour to reach agreement on fixing a single name for the feature concerned.  If they have different official languages and cannot agree on a common name form, it is recommended that the name form of each of the languages in question should be accepted for the charts and publications unless technical reasons prevent this practice on small scale charts e.g. English Channel/La Manche.
  The United Nations Conference on the Standardization of Geographical Names considered the need for international standardization of names of geographical features that are under the sovereignty of more than one country or are divided among two or more countries.  Regarding the names of features beyond a single sovereignty, the United Nations Resolution on the Standardization of Geographical Names Ⅲ/20 (1977) recommended that countries sharing a given geographical feature under different names should endeavor, as far as possible, to reach agreement on fixing a single name for the feature concerned.  The United Nations Resolution on the Standardization of Geographical Names Ⅲ/20 further recommended that when countries sharing a given geographical feature do not succeed in agreeing on a common name, it should be a general rule of international cartography that the name used by each of the countries concerned will be accepted.  A policy of accepting only one or some of such names while excluding the rest would be inconsistent in principle as well as inexpedient in practice. Only technical reasons may sometimes make it necessary, especially in the case of small-scale maps, to dispense with the use of certain names belonging to one language or another.
  In accordance with the IHO Resolution and United Nations Resolution on the Standardization of Geographical Names, Korea suggests that it is most appropriate to use both “East Sea” and “Sea of Japan” concurrently until an agreement on a common name is reached. Since 2002, Korea has held five bilateral meetings with Japan in order to pursue constructive dialogue and reach an agreement on a common name. However, Japan has only responded with indifference to these overtures and continues to insist that nothing other than the single use of “Sea of Japan” is acceptable.
  If this be the case, are map publishers adhering to the use of only “Sea of Japan” for the same reasons that Japan does?  Can this really be justified simply because the name “Sea of Japan” has been widely used during the 20th century?