You Know More Large WWII UK Home FrontOriginal vintage World War Two propaganda poster: "You Know More Than Other People You are in a position of trust. Dont let the fighting forces down. A few careless words may give something away that will help the enemy and cost us lives. Above all be careful what you say to strangers and in public." Typographic poster with the information text in stylised red and white letters over black horizontal stripes and a blue vertical column. Printed for H.