- WW II (POWs)
Tap Codes are a clever and secretive way of communicating using a series of taps or knocks. This form of communication was devised to facilitate discreet messaging, especially in situations where speaking aloud is not an option or could be overheard.
To use Tap Codes, the sender and recipient agree on a simple grid or chart that contains the alphabet and numbers. Each letter is represented by two numbers, typically denoting the row and column of the letter in the grid. For example, the letter "A" might be represented by "1,1," "B" by "1,2," and so on.
When the sender wants to transmit a message, they tap a certain number of times (equal to the first number) followed by a brief pause, then tap again (equal to the second number). The recipient listens and counts the taps, locating the corresponding letter on the grid and writing down the message.
Tap Codes can be useful in various situations, such as prisoners of war communicating in captivity or people signaling each other from a distance without attracting attention. While it may seem simplistic, Tap Codes can be surprisingly effective for conveying simple messages with minimal risk of detection.
Due to the simplicity of Tap Codes, they are not considered a highly secure method of encryption. Nevertheless, they offer a practical solution for discreet communication in certain circumstances where other means are limited or unavailable.