Computer block modeling methods are used to estimate Mineral Resources at the Broken Hill mine (see Section 17 of this report). As a result, no cross-sectional manual polygonal methods are utilized in the estimation process and corrections of drill intercepts to true width are not needed. The extensive drilling into the Broken Hill deposit to date has adequately defined the ore body geometries and continuity. These geometries have been repeatedly confirmed by subsequent mining and drilling continues to extend the deposit at depth, north and south.