Star Wars: The Morning After
A transponder code is a signal burned into a starship’s sublight engines that transmits the ship’s name, type, owner, and other pertinent data. In use since the beginning of spacefaring, transponder codes can be duplicated or removed, though the procedures involved are difficult, expensive, and highly illegal. Ships without transponder codes cannot travel in civilized systems without attracting intense scrutiny.
For most of the galaxy’s history, the Bureau of Ships and Services has issued and tracked transponder codes.