A major challenge when working with open government data is managing, connecting, and understanding the links between references to entities found across multiple datasets when these datasets use different vocabularies to refer to identical entities (i.e.: one dataset may refer to Microsoft as “Microsoft”, another may refer to the company by its SEC filing number as “0000789019”, and a third may use its stock ticker “MSFT”.) In this paper the authors propose a naming scheme based on Web URLs that enables unambiguous naming and linking of datasets and, more importantly, data elements, across the Web. They further describe their ongoing work to demonstrate the implementation and authoritative management of such schemes through a class of web service they refer to as the “instance hub”. When working with linked government data, provided either directly from governments via open government programs or through other sources, the issue of resolving inconsistencies in naming schemes is particularly important, as various agencies have disparate conventions for referring to the same concepts and entities. Using linked data technologies the authors have created instance hubs to assist in the management and linking of entity references for collections of categorically and hierarchically related entities. Instance hubs are of particular interest to governments engaged in the publication of linked open government data, as they can help data consumers make better sense of published data and can provide a starting point for development of linked data applications. In this paper the authors present their findings from the ongoing development of a prototype instance hub at the Tetherless World Constellation at Rensselaer Polytechnic Institute (TWC RPI). The TWC RPI Instance Hub enables experimentation and verification of proposed URI design schemes for open government data, especially those developed at TWC in collaboration with the United States Data.gov program. They discuss core principles of the TWC RPI Instance Hub design and implementation, and summarize how they have used their instance hub to demonstrate the possibilities for authoritative entity references across a number of heterogeneous categories commonly found in open government data, including countries, federal agencies, states, counties, crops, and toxic chemicals.