American spelling vs small-capitalization

American spelling is a noun but small-capitalization is not a noun.

Word	Noun	Adjective	Verb	Adverb
American spelling	Yes	No	No	No
small-capitalization	No	Yes	No	No

American spelling (noun)	small-capitalization (noun)
English orthography used in the United States (characterized by 'analyze', 'center', 'usable')

American spelling (adjective)	small-capitalization (adjective)
	of stocks of companies with a market capitalization of less than one billion dollars