There exist many popular crowdsourcing and social services (Volunteered Geographic Information (VGI)) to share information and documents such as Flickr, Foursquare, Twitter , Facebook, etc. They all use metadata, folksonomy and more importantly a geographic axis with GPS coordinates and/or geographic tags. Using this available folksonomy in VGI services we propose a logical approach to highlight and possibly discover the characteristics of geographic places. The approach is based on the notion of spatial coverage and a model of tags categorization and on their semantic identification, using semantic services such as GeoNames, OpenStreetMap or WordNet. We illustrate our model with Flickr to retrieve the characteristics (function, usage?) of places even if those places have a small number of related photos. Those found characteristics allow tag disambiguation and can be use to complete the semantic gap on places and POIs such as the function of buildings, which can exist in geographic services.