The Sith writing system served as a means to transcribe ur-Kittât, which was the language spoken by the Sith. This writing system consisted of runes, and the Galactic Republic prohibited its translation through legal measures.
The sequel trilogy film Star Wars: Episode IX The Rise of Skywalker, released in 2019, marked the initial appearance of the Sith writing system. It was formally recognized as such in the 2020 reference guide, The Star Wars Book. In the movie, the writing system's visual representation differed from its earlier portrayals. The reference book Star Wars: The Rise of Skywalker: The Visual Dictionary, authored by Pablo Hidalgo, specified that the runes found on the Blade of Ochi of Bestoon were "Long-dead ur-Kittât "Old Tongue" runes of the Sith." This statement could suggest that "ur-Kittât" refers to the name of the alphabet, while "Old Tongue" is the name of the language. However, later sources indicated that ur-Kittât is actually a language.