Renaming of Gulf of Mexico to Gulf of America and of Denali to Mount McKinley In reaction to the Executive Order of the White House as of 20 January 2025 ruling the renaming of Gulf of Mexico to Gulf of America and of Denali to Mount McKinley the International Council of Onomastic Sciences presents the following comment: (1) Gulf of Mexico, Gulf of America: The English name (if it is used in the UK and other English-speaking countries outside US) as well as the names in other languages for this feature are exonyms. Exonyms are in the hands of the receiver/target language, and it is up to the receiver community to decide, whether it wants to maintain the traditional version or adopt the new American endonym. The use of exonyms can never be decided by the donor (in this case US) community. So it may happen that for the US territorial waters the new endonym Gulf of America is used and is also applied in the US as an exonym for international and other territorial waters of the same feature, but that in other countries the exonym Gulf of Mexico and other exonyms remain in use. If a mapwork follows the practice to add to the exonym also the endonym(s), it would have to add along the US coast the new US endonym Gulf of America in brackets (and along the Mexican coast the Mexican endonym a.s.o.). This affects official and private publishers likewise. (Of course, a private publisher may have a specific naming practice, but this would not correspond with the international principles of standardization.) Still another question is, to which extent a White House Executive Order in this matter is binding and for whom it is binding in the US. It may result in the parallel use of both names, in two endonyms, one of which is official. (2) Denali, Mount McKinley: If a linguistic community does not have an exonym for this mountain, name use and publications in this language will have to follow the official endonym change. Many receiver languages, however, did not follow the endonym change from Mount McKinley to Denali and continued to use Mount McKinley as an exonym. In this case the current change means just a return from exonym to endonym status.