commonEndeavour is intended to define a FRBR (Functional Requirements for Bibliographic Records) relationship between two resources that may or may not be modeled as FRBR. This makes it possible to assert that a resource modeled using a vocabulary that does not use the FRBR entity model explicitly is describing the same Work, Expression, Manifestation, and/or Item as another resource (which may or may not use the FRBR model, as well). commonEndeavour is intended to be used merely as a superproperty for WEMI-specific subproperties to inherit from, but there are no restrictions on its use.