This report attempts to explain the concepts of data and information fusion and put them in context in the Command and Control system. We make a review of open literature on information fusion for tactical, ground combat oriented intelligence preparation, present a number of ideas for the treatment of certain information fusion problems and finally describe how we propose to structure the work of creating a demonstration system for information fusion. Such a system would enable the presentation and preliminary evaluation of information fusion methods in various tactical scenarios. We treat only part of the methodology issues which occur in tactical intelligence preparation and which should be amenable to computerized methods. The report addresses a readership of officers and other interested persons. It is written in an informal language without use of such mathematical notation and formal algorithm descriptions which are necessary for a thorough understanding of this methodology.