poster (n.)youdaoicibaDictYouDict[poster 词源字典]
"bill, placard, thing posted," 1838, from post (v.1). Poster boy/girl/child "someone given prominence in certain causes" is attested by 1990, in reference to fund-raising drives for charities associated with disability, featuring child sufferers, a feature since 1930s.[poster etymology, poster origin, 英语词源]