Resources of coal, ore, or minerals which can be mined legally and profitably under existing conditions. The indicated reserve is the estimate of ore computed from boreholes, outcrops, and developmental data, and projected for a reasonable distance on geologic evidence. An inferred reserve is an estimate based on relationships, character of deposit, and past experience, without actual measurements or samples; it should include the limits between which the deposit may lie. A potential reserve is ore not yet discovered but whose presence is suspected; the term is sometimes used for ore not commercially viable at present time. A proved reserve is a resource reliably established by tunnels, boreholes, or mining.