The Kilji data rectangle functioned as a rectangular datacard, utilized by the Kilji species and their Kilji Illumine nation on their warships. During 18 BBY, a Kilji data rectangle was located within a slot on the bridge of the Kilji picket cruiser named Hammer (Hammer's). After the Chiss Ascendancy captured the cruiser, with assistance from several Paccian commandos, Sarsh, the Pathfinder navigator of the picket cruiser, stole battle fleet data pertaining to the Illumine Kilhorde from the data rectangle. Subsequently, the pathfinder gave this information to Mitth'raw'nuruodo, the Chiss Senior Captain who had come aboard the Hammer.
The novel Thrawn Ascendancy: Lesser Evil, published in 2021, featured a Kilji data rectangle; it served as the concluding book in Timothy Zahn's Star Wars: The Ascendancy Trilogy.