The overabundance of information produced by new technologies, if on one side can be considered as a knowledge enrichment in planning process, on the other side it has not improved neither reality understanding nor possibilities of intervention. Old forms of citizens participation to planning process, generally based on assemblies, have been replaced by continuous discussions on social networks, blogs, etc.. The attempt to take into account the huge data flow produced everyday, it is not an easy task for planners. An ontologies based approach can represent an important support to such activities. "Comelicopedia" an European project between Italy and Austria, probably is one of the first experiences in applying ontologies to spatial planning...