"Canada’s “victory nickel,” struck from 1943 to 1945, included a special message to stimulate the war effort: Engraved around the rim were the words WE WIN WHEN WE WORK WILLINGLY in Morse Code. The coin was reissued in 2005 to commemorate the 60th anniversary of V-E Day."Found in the Futility Closet.
Steganography is the practice of concealing a file, message, image, or video within another file, message, image, or video. The word steganography combines the Greek words steganos (στεγανός), meaning "covered, concealed, or protected", and graphein (γράφειν) meaning "writing".