Description:

The LRMoo model includes all classes and properties required, in addition to classes and properties already declared in CIDOC CRM, to express the concepts covered by IFLA LRM. Unlike in FRBRoo, no classes that are exact equivalences of CIDOC CRM classes are declared, even when those classes are required as direct equivalences to IFLA LRM classes. LRMoo is strictly an extension of CIDOC CRM and cannot be implemented without using key classes and properties from CIDOC CRM.

LRMoo only expands on IFLA LRM in a few limited areas. LRMoo does not include refinements for particular types of resources. In contrast, in FRBRoo some aspects were modelled in great detail, for example performing and recording of performances. This level of detail led to a rather lengthy model, with 48 classes and 72 properties, which was deemed too complex and led to the desire to establish a “core” FRBRoo model. In addition, these specialized subclasses of F1 Work or F2 Expression were redundant as their properties were semantically equivalent to the properties of their superclasses, just declared with different labels. Some entity types and properties were therefore deprecated in the transition to LRMoo, but the expressivity of LRMoo is not reduced with respect to FRBRoo. All these aspects can be fully represented with more general supertypes in LRMoo or CIDOC CRM.