A digital work for use within a rights management system for controlling use
of
the digital work in accordance with usage rights. The work is organized into an
acyclic structure and includes a contents file including information related to
content that can be interpreted by an interpreter, and a description tree file
including descriptor blocks organized in a hierarchical manner. At least some of
the descriptor blocks contain usage rights associated with the content. The usage
rights specify a manner of use for the content.
