I Love It When You Talk Retro: Hoochie Coochie, Double Whammy, Drop a Dime, and the Forgotten Origins of American Speech by Ralph Keyes. You can read an interview with Keyes here.
From the interview:
I was surprised to find out that there were no "secret decoder rings." There were secret decoder pins, but no rings.
Sir Harold Gillies, sculptor Kathleen Scott, artist Francis Derwent Wood and others worked together during World War to create masks for British troops disfigured during World War I. The official name for the facility was "Masks for Facial Disfigurement Department." But the troops called it "The Tin Noses Shop."