credo vs doctrine

credo and doctrine both are nouns.

Word	Noun	Adjective	Verb	Adverb
credo	Yes	No	No	No
doctrine	Yes	No	No	No

As nouns, doctrine is a hypernym of credo; that is, doctrine is a word with a broader meaning than credo:

credo: any system of principles or beliefs
doctrine: a belief (or system of beliefs) accepted as authoritative by some group or school

Other hypernyms of credo include ism, philosophical system, philosophy, school of thought.

credo (noun)	doctrine (noun)
any system of principles or beliefs	a belief (or system of beliefs) accepted as authoritative by some group or school