Transnational and cross-border co-operation have a growing need (e.g. EU-enlargement) for a precise understanding of the partner’s concepts and the planning systems they are embedded in. The improvement of solving similar problems in different BSR countries and on transnational activities can best be achieved by exchange of experiences and ideas, mutual training and further education as well as providing access to information and good practice examples. Achievements: COMMIN facilitated future transnational projects and investment activities in the BSR by having created for the first time a reliable linguistic basis for all BSR countries, offering extended information (English and respective national languages) on the different planning and constitutional systems, their horizontal comparison, examples of planning practice, providing definitions for and the meaning behind the most relevant planning terms in English specific for the BSR and for each country, offering information on European scale, and making all information general available within an up-to-date information tool (Web Portal).More than 190 professionals and practitioners in transnational spatial development activities were trained in eight international training sessions and two summer schools in order to raise their capability for transnational cooperation and trans-sector analysis.Two thematic workshops (“TEN-T” and “ICZM”) with experts from different BSR countries, a good practices analysis of selected BSR INTERREG III B and IIC projects and the documentation of the Final Conference resulted in additional publications and recommendations.Work PackagesWP 1: Web Portal on Spatial DevelopmentWP 2: Advanced Training Network on Spatial Planning and DevelopmentWP 3: Transnational Exchange of innovative approaches of Spatial DevelopmentSumming up, the project made communication in transnational and cross-border projects more efficient and facilitated, created a common basis of knowledge, trained future planners and regional developers in the BSR, created a basis of information for everybody who is interested in the BSR, and thus made the matter of spatial planning and regional development generally known. It broadened the knowledge base, exchanged experiences and helped to deliver benefits from spatial planning to the final addressees.Even after project closure most outputs (more than 3.500 pages in print) are public available as html and for download on the user friendly Web Portal, supplemented by various internal and externals links, many features and external material to ease future transnational cooperation around the Baltic Sea.