Obsolete names are names that are no longer official, because they have been officially replaced by other names. As far as replaced names are concerned, it is wise to maintain the most commonly known of these for one more edition of an atlas or map series sheet as a secondary name, in order to let the users get acquainted with the new name, and make them aware of which place the old name has been superseded.

A special problem occurs when it is known that names have been changed, for instance because the official language of a country was changed, but the new name forms are not known as yet. It happened for instance with the Central Asian republics that replaced Russian with Turkmen, Uzbek, Kazakh, Kyrghyz etc. as official language in the 1990s. Atlas editors were forced to stick to the Russian names for a transition period, until it was made known what the local language versions of these names were, and how these were to be converted to the Roman alphabet.

For an exercise on this topic see issue 3 of exercise "Some editorial issues to solve"