The registry of the non-autonomous territories in accordance with the United Nations, includes Western Sahara, Guam, American Samoa, Nouvelle-Calédonie, the Pitcairn islands, Tokelau, Anguilla, the Bermudes, the British Vierges Islands, the Caimans islands, the Falkland islands, Gibraltar, Montserrat, Sainte-Hélène, Ascension et Tristan da Cunha, the Turques-et-Caïques islands, the American Vierges islands, and French Polynésie.

The list of countries and overseas territories includes the dependencies as well as the overseas territories of the Member States of the European Union, but without them constituting part of the European Union.
These entities are: Groenland, Nouvelle-Calédonie and itspossessions, the French Polynésie, Saint-Pierre-et-Miquelon, the Terres australes and the French Antarctic territories, Wallis et-Futuna, and Saint-Barthélemy.
There are also: Aruba, Bonaire, Curaçao, Saba, Saint-Eustache and Saint-Martin. And finally: Anguilla, the Bermudes, the Caïmans islands, the Géorgie du Sud-et-the Southern Sandwich islands, the Falkland Islands, Montserrat, the Pitcairn Islands, Sainte-Hélène, Ascension and Tristan da Cunha, the Antarctic British territory, British Indian ocean territory, the Turques-et-Caïques islands and the British Vierges islands .

It’s not difficult to observe that within those two lists there is a non empty structure.
In a strategic context that means, that despite the presence of an entity in the first list, its presence in the second one, provides it with a status fundamentally different in regards to the others.
As far as Gibraltar is concerned, it constitutes part of the European Union.
As a result we very well observe the arbitrary nature of its presence in the first list.
And in this context it is wise to seek out for the reason of the presence of Western Sahara in that first list, taking into account all the other elements of that specific registry.