Interoperability has been identified as a major issue to be addressed by every e-government agency. An interoperability framework aims to provide the basic standards that every department which is relevant for the e-government strategy implementation should adopt. Criteria for selection and inclusion of standards in an interoperability framework are crucial, since they influence the utility that the framework delivers to the e-government agencies. This paper identifies and compares the policies of the main e-government agencies in the definition of these criteria and it checks the policies against the practice that they exhibit in the actual interoperability frameworks.