FIELD: information technologies.
SUBSTANCE: medium comprises an area in a data area, where a unit of defect unit substitution is stored. A record of a list of defects has the first indicator, specifying a physical location of a defect unit, the second indicator, specifying a physical location of a substitution unit corresponding to a defect unit, and information on status of a defect unit and a substitution unit. Information on status comprises information, specifying whether a defect unit is single or serial, and if a defect unit is serial, the second information, specifying whether a defect unit is an initial unit or an end unit among serial defect units. The list of defects additionally contains information on general number of records in the list of defects contained in the list of defects.
EFFECT: improved efficiency of optical disc space use.
2 cl, 12 dwg
