In our era of growing international cooperation, researcher mobility and online communication, interoperability of research information becomes a crucial aspect as this information is more and more distributed over various, and often internationally dispersed, resources. The consequence of this is that, in order to get "the full picture" of a research project, for example, the performance or CV of a researcher or the information needed for evaluation and benchmarking of research, it is necessary to combine a multitude of information sources. This aspect, however, requires that the pieces of information are understood in the same way by the various systems and users involved, are uniquely identified no matter in which system they reside, and are easily and transparently exchanged between the various systems in the information network. In short, interoperability of research information requires the three pillars of standardisation to be in place: standard definitions and vocabularies (of objects and entities), unique and persistent identifiers, and a standard exchange format. Today, solutions are available for all three pillars, worked out by various organisations in the research information community, e.g. CASRAI (for the definitions), ORCiD and ISNI (for the identifiers) and euroCRIS (for the exchange format - CERIF). The challenge before us is to formulate an integrated vision, including the three pillars, and - next - to concretely and optimally implement them in our research information practices and infrastructures.