The purpose of this disc is for measurement and adjustment of error correction ability against defects on a disc.
 This is simulated disc with fingerprint when handling disc is expected and dusts or stain adhered on a disc surface or lack of pits.

There are three kinds of defects, which simulated on disc surface.
1.Dots and Band: Simulation of stains or dust on read-out surface.
2.Fingerprint: Simulation of fingerprint on read-out surface.
3.Interruption: Simulation of lack of pit on information layer.