All the hollow measurements valid worldwide today are based on the metric system (Table 1); see also under Dimensions. In addition, very old hollow measures are still in use (Table 2). The Anglo-American measurement systems are almost only used in the USA, England and some other countries (Table 3). The old Roman hollow dimensions are included under Congius. In the sources on old units of measurement, the information on volumes is often different and the differences are sometimes considerable. See also other lists of measures under the keywords barrel types, area measures, bottles, units of measurement, area under vines, wine containers and wine production quantities.