Urban actors create cities through negotiations that employ shared, symbolic intermediaries, creating a commons or shared space for activities. This commons may take the form of an enclave, an armature or a heterotopia. Cities are made up of shifting, recombinant relationships between these three elements. The enclave is predominant in the archaic, hierarchic (Asian, Islamic, medieval European) spatial order of localization. The armature is predominant in the spatial order of extension in the infrastructure or public spaces of the modern industrial city and the heterotopia predominates in the network space of the post-industrial city. These three organizational devices are fundamental to the activities of urban actors, who need shared, common, communicative, collective, conceptual models in order to create and operate the city successfully (Shane 2005: 176-227).