Region Codes Motion picture studios want to control the home release of movies in different countries because theater releases are not simultaneous around the globe. They have required that the DVD standard include codes that can be used to prevent playback of certain discs in certain geographical regions. Each player is given a code for the region in which it is sold. The player will refuse to play discs that are not allowed in that region. This means that discs bought in one country may not play on players bought in another country.
Regional codes are entirely optional.
Discs without codes will play on any player in any country. Most DVD-ROM drives let you change the region code a few times, usually between 5 and 9. Once a drive has reached the limit it can not be changed again unless the vendor or manufacturer resets the drive. When using an RPC2 drives the software DVD decoderuses the DVD ROM to control the region information. As usual there are many people hard at work to get around this RPC2 locking problem, but for most of us who want to use discs from different regions it is just easier to get an RPC1 drive.