The term 'MEDIUM BOARD' is a reference to the Ouija BOARD, which is a flat BOARD marked with the letters of the alphabet, the numbers 0–9, the words 'YES', 'NO', 'HELLO' and 'GOODBYE', along with various symbols and graphics. It is used as a divination tool, with participants placing their fingers on a planchette, or movable indicator, and using it to spell out messages. The Ouija BOARD has been around since the late 19th century and is believed to be a means of communicating with spirits.