Green’s Dictionary of Slang

1. (Irish) the human face.

1965

(con. 1940s) B. Behan Confessions 52: They were coming up smiling all over their plaques.

2. (N.Z. prison) lies.

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 142/1: plaque n. lies.