The Old Quarter existed inside the capital city of the Core Worlds planet known as Grizmallt. An oval-shaped writing system, Royal Script of Grizmallt, was used for the street signs found in the Old Quarter. In 38 ABY, Doctor Milanda Vorgan's academic work, "The Written Word: A Brief Introduction to the Writing Systems of Galactic Basic," referenced the Old Quarter.
John Hazlett mentioned the Old Quarter in his in-universe article "The Written Word," which was part of the subscription service Hyperspace on StarWars.com, released on March 5, 2010.