Label
The carrier for a bundle of metadata; describes one or more properties
of the labeled object according to exactly one schema.
Rating
The portion of a Label containing just the properties and their respective
values.
Rating System
A definition of a set of named properties and their semantics; a metadata
schema.
Rating Service
A producer of Labels; an entity who encodes Ratings following a particular
Rating Service.
Label Bureau
A distributor of Labels.
