https://publicpolicy.googleblog.com/2008/04/how-google-determines-names-for-bodies.html
When our policy says that we display the “primary, common, local” names for a body of water, each of those three adjectives has an important and distinct meaning. By saying “primary”, we aim to include names of dominant use, rather than having to add every conceivable local nickname or variation. By saying “common”, we mean to include names which are in widespread daily use, rather than giving immediate recognition to any arbitrary governmental re-naming. In other words, if a ruler announced that henceforth the Pacific Ocean would be named after her mother, we would not add that placemark unless and until the name came into common usage. Finally, by saying “local”, we aim to reflect the primary and common names used by countries that actually border the body of water, as they are the countries recognized under international law as having a special sovereign stake in it.
I think you might be a bit lost