The Italian Official Toponyms of the IGM database were extracted from the Official Topographic Map of Italy at scale 1: 25000 (Series 25v). The positions of these toponyms are expressed in meters in the Gauss-Boaga Rome 40 System and in the UTM ED50 System.

The position of the toponyms referring to geographical objects represented on the map with punctual conventional signs (isolated houses, mines, wells, sources) is located at the centre of the relative symbols.

The centres of the line in witch the toponyms are written identify the positions of the toponyms referring to geographic objects represented on the map with linear conventional signs (roads, rivers, channels). In such cases, also, place names are recorded in the database every time they appear within the map; therefore they differ only for positions, describing the same geographical object.

The positions of the toponyms related to geographical areas (lakes, inhabited centers, forests, marshes) are determined by the centroides of the surfaces, which in particular cases may be outside the areas. In these cases, the location of the toponyms are located from the object's points closest to the centroides of the same surfaces.

The toponyms referring to extended geographical areas (mountains, plains, beaches, woods), that do not have precise spatial delimitations, have their application points coinciding with the centroides of the minimum rectangle in witch the toponyms are written.

Each toponym is associated with:

• any second name;
• the coordinates;
• the primary code (DGIWG Feature and Attribute Coding Catalogue - FACC);
• 1 to 3 attributes that qualify it;
• the sheet of map in which it is positioned;
• the edition of this map;
• the relative date of reconnaissance;
• the East coordinate in meters (Gauss-Boaga Roma 40 and UTM ED50 Systems);
• the North coordinate in meters (Gauss-Boaga Roma 40 and UTM ED50 Systems);
• the coordinates of the minimum rectangle containing the toponym (north-west and south-east vertices, in the UTM ED50 System).