capital of Djibouti vs national capital

capital of Djibouti and national capital both are nouns.

Word	Noun	Adjective	Verb	Adverb
capital of Djibouti	Yes	No	No	No
national capital	Yes	No	No	No

capital of Djibouti (noun)	national capital (noun)
port city on the Gulf of Aden; the capital and largest city of Djibouti	the capital city of a nation