The J1939 Handbook Supplement is a set of Recommended Practices defining a data network for use in a wide variety of applications, with primary emphasis to date on heavy-duty vehicles. It was designed to support general-purpose information transfer as well as the more demanding tasks of distributed control systems on board a vehicle. The top-level document provides an overview and serves as a master control for common definitions used by multiple applications and industries. The J1939/0X documents define the use of these standards in a particular application or industry, allowing J1939 to be tailored as needed without having to include definitions that do not apply. The intent of J1939 is to allow plug and play capability for any device that is added to the network.