Definition
A specialization of InformationStore. Each instance of PublishedMaterial is either a conceptual work (an instance of ConceptualWork) with instantiations which have been produced for distribution, or an information-bearing thing (an instance of InformationBearingThing) which has been produced for distribution. Note that "published" here does not mean "printed and physically distributed", since intangible information-bearing things can be published using the WorldWideWeb_Concrete, or broadcast on the airwaves. Notable specializations of PublishedMaterial include Book_CW, RecordedVideoProduct, and RecordedSoundProduct.
