Reference models, often called core models are developed in various application domains. Until now, no computational support exists for the task of verifying the conformity between such core models and their domain models. The approach developed at Bamberg University uses Semantic Web technologies to examine whether or not a domain model is a derivation of a core model. This ontology-based conformity veriWcation supports an iterative modeling process in which core or domain models are modiWed. Inference services as provided by ontologies can be used to analyze the relationships between core and domain models. For example, it is possible to formally prove which speciWc relations hold between two types of models and compare the result with the intentions of the domain experts involved in the modeling. As a consequence, knowledge not explicitly represented is revealed. In case that the domain model does not conform to the core model, an interpretation of the inference results is provided in ordinary language giving the domain experts hints on how to modify either the core model, the domain model or both. We evaluated our approach by applying it to a core model and a domain, hence national model from the cadastral domain. Conformity was veriWed between the core cadastral model proposed by [