Similar to how BIBFRAME identifies Works as an abstract concept of an idea, but in the broader sense. Works from BIBFRAME are meant to represent the idea of the creation itself rather than a more global concept. These concepts are not related to any type of entity. They can be classified in hierarchy such as "Philosophy → Faith → Religion" or "Mind → Dreams → Dream Interpretation"
The promise of concept-oriented catalogs is still largely unrealized in the library world. Not only do current library catalogs often do little with conceptual knowledge, but proposals for future catalog architectures also often stick to keeping a tight focus on resources and make other concepts secondary. — John Mark Ockerbloom, Understanding concept-oriented catalogs, 2009.