A digital work and data structure for use within a system for enforcing usage rights associated with digital content, including a description tree file including descriptor blocks organized in a hierarchical manner. The descriptor blocks include usage rights associated with the digital content, and specifying a manner of use of the digital content, a content identifier including a unique identifier of the digital content, and a usage rights portion including the usage rights. The digital content includes plural content portions, and the usage rights portion includes a rights code field including a code indicative of the manner of use of the digital content and a status information field including information relating to a state of the manner of use.