6. national standard

A national standard of exonyms is needed in every language. Look at some examples of exonyms taken from Dutch atlases, before exonyms were standardized there:

Bosatlas (1976)	Oosthoek atlas (1978)	Meulenhoff atlas (1978)
Haleb (Aleppo)	Aleppo	Halab (Aleppo)
Bur Said (Port Said)	Port Said	Boer Saďed (Port Said)
El Suweis (Suez)	Suez	As Soewees (Suez)
Dimachq (Damascus)	Damascus	Dimasjq (Damascus)
Mina Hassan Tani (Kenitra)	Mina Hassan Tani (Kenitra)	Mina Hassan Tani (Kenitra)
Tarabulus (Tripoli)	Tripoli	Tarabloes (Tripoli)
Khartum	Khartoum/Khartoem	Al Chartoem
El Djezair (Algiers)	Alger/Algiers	Al Djazaair (Algiers)

Blue line = source