View source for Book type

{{About|the book type field of a DVD|the book publishing software|Booktype}}

{{Unreferenced|date=April 2024}}
The '''book type''' is a field of four [[bit]]s at the start of every [[DVD]] (in the physical format information section of the control data block) that indicates what the physical format of the disc is.  Many devices will use this field to determine how the disc should be treated.

One common cause of compatibility problems is the failure of a device to recognize the book type of the disc, most likely because the device had been manufactured before that particular book type was defined; for example, most DVD playback devices made before mid-2004 cannot recognize the relatively new [[DVD+R DL]] Book Type. For [[DVD+R]], [[DVD+RW]], and [[DVD+R DL]] discs, it is possible to change the book type field value to the value associated with the DVD-ROM format (or in some rare and unorthodox cases, even the value associated with the DVD-R format—though only DVD+R can be changed to this) in order to fool older devices, which is a trick known as ''bitsetting''.

These are the possible values of the Book Type Field:
{| class="wikitable"
|-
! Value !! Meaning
|-
| 0000 || [[DVD-ROM]], either one or two layers
|-
| 0001 || [[DVD-RAM]]
|-
| 0010 || [[DVD-R]] or [[DVD-R DL]], depending on the [[Part Version]] field
|-
| 0011 || [[DVD-RW]]
|- 
| 1001 || [[DVD+RW]]
|- 
| 1010 || [[DVD+R]]
|- 
| 1101 || [[DVD+RW DL]] (never released)
|- 
| 1110 || [[DVD+R DL]]
|}

== See also ==
* [[Rainbow Books]], the other types of books for optical discs
* [[File format#Magic number|File format § Magic number]]

==References==
{{reflist}}

== External links ==
* [https://web.archive.org/web/20090227032500/http://cdfreaks.com/reviews/Increased-compatibility-DVD-bitsetting CD Freaks Article] ''Increased compatibility: DVD bitsetting''
* [https://archive.today/20130414174542/http://www.dvdplusrw.org/Compatibility.asp?mid=0&sid=2&aid=59 DVDPlusRW.org Search page] Search devices for Compatibility Settings

[[Category:DVD]]