For the supplementary quantity the quantity units recommended by the World Customs Organization (WCO) (see Annex I) for individual commodities (6-digit sub-headings) are enforced in order to allow comparability across countries. The quantity information reported for a particular commodity has to be reported in the WCO recommended unit (WCO RU) or it must be possible to convert the reported quantity unit into the WCO RU. Otherwise the quantity information is disregarded. Previously, there was no procedure in place to ensure that the quantity information for individual commodities would follow a specific quantity unit.