Software engineering has always had software reuseas one of its key tenets. In both Service-Oriented and Resource-Oriented Architectures visibility is a prerequisite for fulfillingtheir respective promises, namely easier reuse of services andresources. Resource registries are a way to achieve such visibility.We argue that resource registries must separate technical,semantic and organizational aspects and leverage popular existingstandards. This way they are able to adapt to domainspecific requirements and a multitude of categorizations of andassociations between resources. These arguments are backed up by examples primarily from the nascent pan-European eGovernment Resource Network.