The avoirdupois system (/ˌævərdəˈpɔɪz, ˌævwɑːrdjuːˈpwɑː/; abbreviated avdp.) is a measurement system of weights which uses pounds and ounces as units. It was first commonly used in the 13th century AD and was updated in 1959. Over time, the desire not to use too many different systems of measurement allowed the establishment of "value relationships", with other commodities metered and sold by weight measurements such as bulk goods (grains, ores, flax) and smelted metals; so the avoirdupois system gradually became an accepted standard through much of Europe.