promulgation vs banns

promulgation and banns both are nouns.

Word	Noun	Adjective	Verb	Adverb
promulgation	Yes	No	No	No
banns	Yes	No	No	No

As nouns, banns is a hyponym of promulgation; that is, banns is a word with a more specific, narrower meaning than promulgation:

promulgation: a public statement containing information about an event that has happened or is going to happen
banns: a public announcement of a proposed marriage

Other hyponyms of promulgation include advisory, handout, press release, release, notice, program, programme, wanted notice, wanted poster.

promulgation (noun)	banns (noun)
the formal act of proclaiming; giving public notice	a public announcement of a proposed marriage
a public statement containing information about an event that has happened or is going to happen
the official announcement of a new law or ordinance whereby the law or ordinance is put into effect