This International Standard specifies the mechanical, physical and optical characteristics of an 80 mm and a 120 mm DVD Re-recordable disk to enable the interchange of such disks. It specifies the quality of the prerecorded, unrecorded and the recorded signals, the format of the data, the format of the information zone, the format of the unrecorded zone, and the recording method, thereby allowing for information interchange by means of such disks. This disk is identified as a DVD Re-recordable (DVD-RW) disk. This International Standard specifies ? 80 mm and 120 mm nominal diameter disks that may be either single or double sided, ? the conditions for conformance, ? the environments in which the disk is to be operated and stored, ? the mechanical and physical characteristics of the disk, so as to provide mechanical interchange between data processing systems, ? the format of the pre-recorded information on an unrecorded disk, including the physical disposition of the tracks and sectors, the error correcting codes and the coding method used, ? the format of the data and the recorded information on the disk, including the physical disposition of the tracks and sectors, the error correcting codes and the coding method used, ? the characteristics of the signals from pre-recorded and unrecorded areas on the disk, enabling data processing systems to read the pre-recorded information and to write to the disks, ? the characteristics of the signals recorded on the disk, enabling data processing systems to read the data from the disk. This International Standard provides for interchange of disks between disk drives. Together with a standard for volume and file structure, it provides for full data interchange between data processing systems.