flag rank vs rating

flag rank and rating both are nouns.

Word	Noun	Adjective	Verb	Adverb
flag rank	Yes	No	No	No
rating	Yes	No	No	No

As nouns, rating is a hypernym of flag rank; that is, rating is a word with a broader meaning than flag rank:

Other hypernyms of flag rank include military rank, military rating, paygrade.

flag rank (noun)	rating (noun)
the rank of a flag officer	act of ascertaining or fixing the value or worth of
	an appraisal of the value of something
	standing or position on a scale
	rank in a military organization