A comparison between Sardinian strategic plans (SPs) and implementation plans of historic centers (IPHCs) shows that a general lack of coordination and integration among these municipal planning instruments and a sort of a communicative short circuit are taking place. On the one hand, SPs tend to neglect the importance and the intrinsic value of cultural heritage within historic districts, and, consequently, to undervalue the systemic and general potential of interventions (often limited to punctual and fragmented restorations of buildings) in the historic centers; and, on the other hand, IPHCs propose analyses of municipal historic settlement systems characterized by excessively philological and self-referential attitudes. This paper proposes a discussion on the definition and implementation of IPHCs with the general goal of orienting their conservative character, mainly based on the urban settlement system’s restoration and restructuring, in order to generate conditions favorable to local economic and social development, following the strategic planning conceptual framework. Moreover, within the framework of the Regional Landscape Plan (RLP), and after providing the reader with a thorough presentation of some important technical issues related to IPHCs and a discussion on the semantics of the term “ontology,” this paper discusses some key points concerning the ontology of the IPHCs procedure, that is the spatial analysis of the IPHCs and implied planning measures.