posting vs placard

posting and placard both are nouns.

Word	Noun	Adjective	Verb	Adverb
posting	Yes	No	No	No
placard	Yes	No	Yes	No

As nouns, posting and placard are synonyms defined as:

posting and placard: a sign posted in a public place as an advertisement

Other synonyms of posting include bill, card, notice, poster.

posting (noun)	placard (noun)
the transmission of a letter	a sign posted in a public place as an advertisement
a sign posted in a public place as an advertisement
(bookkeeping) a listing on the company's records

posting (verb)	placard (verb)
	publicize or announce by placards
	post in a public place