Region coding

A regional lockout (or region cording) is a class of digital rights management preventing the use of a certain product or service, such as multimedia or a hardware device, outside of a certain region or territory. A regional lockout may be enforced through physical means, through technological means such as detecting the user's IP address or using an identifying code, or through unintentional means introduced by devices only supporting certain regional technologies (such as video formats, i.e., NTSC and PAL).

A regional lockout may be enforced for several reasons, such as to stagger the release of a certain product, to hinder grey market imports by enforcing price discrimination, or to prevent users from accessing certain content in their territory because of legal reasons (either due to censorship laws, or because a distributor does not have the rights to certain intellectual property outside of their specified region).

The DVD, Blu-ray Disc, and UMD media formats all support the use of region coding; DVDs use 8 region codes (Region 7 is reserved for future use; Region 8 is used for "international venues", such as airplanes and cruise ships), and Blu-ray Discs use 3 region codes corresponding to different areas of the world. Currently, most Blu-ray discs are region-free.

On computers, the DVD region can usually be changed five times. Windows uses three region counters: its own one, the one of the DVD drive, and the one of the player software (occasionally, the player software has no region counter of its own, but uses that of Windows). After the fifth region change, the system is locked to that region. In modern DVD drives (type RPC-2), the region lock is saved to its hardware, so that even reinstalling Windows or using the drive with a different computer will not unlock the drive again.

Unlike DVD regions, Blu-ray regions are verified only by the player software, not by the computer system or the drive. The region code is stored in a file and/or the registry, and there are hacks to reset the region counter of the player software. In stand-alone players, the region code is part of the firmware.

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