Morse code were also published in "QST", Another example occurred in 1966 when prisoner of war Jeremiah Denton, brought on television by his North Vietnamese captors, Morse-blinked the word "TORTURE". In these two cases, interpreters were available to understand those series of eye-blinks. International Morse code is composed of five elements: Morse code can be transmitted in a number of ways: originally as electrical pulses along a telegraph wire, but also as an audio tone, a radio signal with short and long tones, or as a mechanical, audible, or visual signal (e.g. a flashing light) using devices like an Aldis lamp or
Machine Identification Code Machine Identification Code A Machine Identification Code (MIC), also known as printer steganography, yellow dots, tracking dots or secret dots, is a digital watermark which certain color laser printers and copiers leave on every single printed page, allowing to identify the device with which a document was printed and giving clues to the originator. Developed by Xerox and Canon in the mid-1980s, its existence became public only in 2004. In 2018, scientists developed privacy software to anonymize prints in order to support whistleblowers publishing their work. In the mid-1980s Xerox pioneered an encoding mechanism for a unique number represented by