Two-dimensional (2D) codes offer several advantages over conventional bar codes for marking parts and assemblies. This paper will review the key attributes of 2D codes, including data density, readability, and error correction capability. Featured applications will demonstrate the use of 2D codes to identify and track automotive parts throughout production and assembly processes. Although 2D codes can be applied by contact and non-contact technologies, this paper will focus on ink jet printing and laser coding to provide specific examples of the benefits of on-line, real time, non-contact product identification. Finally, code reading devices, on-line and hand-held, will be introduced.