A large number of studies have detected that within the EU multilevel governance there is a transformation toward a hybrid knowledge co-production that overcomes traditional categories such as locality or embeddedness. There, a sort of sustainable decision-making knowledge is co-developed and theoretically supposed to be applied top-down on the national level of EU member states. However, in practice such processes of unification are always associated with a risk of limited compliance with specific national situations and with a specific national “world of relevancies”. Despite the rise in popularity of these top-down initiatives within international policy levels, there is a lack of studies that empirically analyze how national policy systems respond to these global standardization approaches. Therefore, the central aim of this study is twofold: Based on an exemplary case of an international information system co-produced by an expert group of the European Commission, it first reconstructs whether and how transnational information is integrated on the national policy level. Second, it elucidates factors limiting an application. The results show that this international knowledge system was used for basal purposes and was mainly challenged by non-compliance with national specificities and the existence of alternative knowledge sources.