I'm loving this poster!
It was designed during the scecond world war to be used in the event of a German invasion. However, it was never released to the public and got forgotton until 2000 when a book dealer found a copy in a box of old books.
The original was in pillar box red, but has since been reprinted in lovely pastel colours. I'd like an eggshell coloured one in my hallway.
I just love it's message, so typically British.