The digital rights management (DRM) capabilities are crucial to MPEG-21, as they are to other emerging multimedia standards, so that publishers in the recording and movie industries will adopt the standard without fear of losing control of copyrighted works.
Part 5 of the standard, the Rights Expression Language (REL), lets multimedia publishers designate rights and permissions for how consumers can use their content. The REL expression "play," for instance, would let the consumer use the material in a "read only" mode, while other expressions could allow more flexibility in playback and reproduction.
REL also lets consumers establish privacy preferences for their personal data.
Part 6 of the standard, the Rights Data Dictionary (RDD), defines terms that publishers can use when working with REL.
Other important standards from MPEG, a working group of the International Organization for Standardization/International Electrotechnical Commission (ISO/IEC), include the MPEG-4 group of technologies, which have gained momentum in the past year after winning and .
Digital rights management methods remain high on the to-do list for other MPEG projects as well. In March, the Internet Streaming Media Alliance, whose members include Apple and RealNetworks, published for public comment.