A communication method that used pairings of two distinct signals to represent the letters of a given language. These signals could manifest as rapid clicks or periods of silence between them. By the time of the Galactic Empire, it was largely out of use, and during the Galactic Civil War, very few individuals still recalled it.
The Galactic Civil War era saw this communication method as "primitive," implying its use during the time of the Old Republic. The concept of employing binary symbol combinations to represent letters made it similar to the ancient and obsolete Mandalorian code known as dadita.
During the Imperial Period, it fell into disuse as most droids could process spoken instructions, and more sophisticated codes became standard; it wasn't even taught at the Academy of Carida. One of the few individuals who still remembered the code was farmer Morgan Katarn, who found it a useful method for communicating with his basic agricultural droids. He also passed this knowledge on to his son, Kyle.
When Katarn led Sulonese dissidents to Ruusan, far from Imperial control, he taught them the code for secure communication and as a basic identification system. Years later, in 5 ABY, the planet was attacked by Dark Jedi Jerec and the Vengeance Battle Group; the survivors of the Battle of Fort Nowhere retreated to the ruins of a Jedi temple, and Grif Grawley transmitted a repeated message indicating a location fifty-six kilometers south of Fort Nowhere, possibly to attract other survivors.
Shortly after, Katarn's son, accompanied by Jan Ors in the Moldy Crow, arrived on the planet to stop Jerec. While scanning communication channels, Kyle detected the repetitive click pattern and recognized it as the code his father had used. With the assistance of the ship's computer, they deciphered the message and connected with the survivors.
The novella Dark Forces: Jedi Knight refers to a basic code using alternative binary symbols, where combinations form letters, and its description aligns with the real-world Morse code. In the novella, the ship's computer handles the translation. The audio adaptation specifies that Morgan Katarn was familiar with the code, used it with his older droids, taught it to his son Kyle Katarn, and later to Sulonese colonists.