This document specifies the mechanical, physical and optical characteristics of a 120 mm rewritable optical disk with a capacity of 100,0 Gbytes. It specifies the quality of the recorded and unrecorded signals, the format of the data and the recording method, thereby allowing for information interchange by means of such disks. User data can be written, read and overwritten many times using a reversible method. This disk is identified as a BD rewritable disk.This document specifies the following:— the one disk type;— the conditions for conformance;— the environments in which the disk is to be operated and stored;— the mechanical and physical characteristics of the disk, in order to provide mechanical interchange between data processing systems;— the format of the 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 recorded on the disk, enabling data processing systems to read data from the disk.This document 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.