The DVD specifications created and updated by theDVD Forumare published as so-calledDVD Books(e.g. DVD-ROM Book, DVD-Audio Book, DVD-Video Book, DVD-R Book, DVD-RW Book, DVD-RAM Book,DVD-ARBook,DVD-VRBook, etc.).
Some specifications for mechanical, physical and optical characteristics of DVD optical discs can be downloaded as freely available standards from theISOwebsite.There are also equivalentEuropean Computer Manufacturers Association(Ecma) standards for some of these specifications, such as Ecma-267 for DVD-ROMs.Also, theDVD+RW Alliancepublishes competing recordable DVD specifications such as DVD+R, DVD+R DL, DVD+RW orDVD+RW DL. These DVD formats are also ISO standards.
Some of DVD specifications (e.g. for DVD-Video) are not publicly available and can be obtained only from the DVD Format/Logo Licensing Corporation for a fee of US $5000.Every subscriber must sign anon-disclosure agreementas certain information in the DVD Book is proprietary and confidential.