Book Type
With Book Type a 4-bit field in the lead-in area of a is DVD -Mediums described containing accurate information about the media type (eg. -RW, + RW and + RW DL). This format specification is evaluated by most DVD players or DVD drives in order to use this information to determine the appropriate handling of the medium.
The software in many older drives or DVD players does not recognize the newer media types such as DVD + R Dual Layer. Therefore these cannot be read with such drives. However, some DVD recorders make it possible to manually determine the book type to be saved when creating a burned DVD, for example the identifier "DVD-ROM" can be used for a "DVD + RW" medium. This enables improved compatibility with the older drives.
| 0000 | DVD-ROM |
| 0001 | DVD-RAM |
| 0010 | DVD-R , DVD-R DL |
| 0011 | DVD-RW |
| 1001 | DVD + RW |
| 1010 | DVD + R |
| 1101 | DVD + RW DL (never produced) |
| 1110 | DVD + R DL |