The CHELEM-INT database includes bilateral flows of international trade, in current dollars, stretching back to 1967. The diverse data available is rendered coherent and is harmonized using an accounting framework that covers the whole of the world, and all goods and commodities, detailed to a level of 71 product categories CHELEM , 43 GTAP branches or 147 ISIC posts at 4 digits (which are supplemented by an "unallocated products" heading and a "total of products" heading). For each year and each product category, trade between geographic zones (countries or country groups) are represented by a single matrix with 96 rows and 96 columns. These are made up of:
F 94 elementary zones;
F 1 heading for products not elsewhere classified, whose origin and destination are not known;
F 1 heading for all imports from all origins taken together (last row) and for all exports to all destinations taken together (last column).

Thus the intersection of row i and column j provides the exports of zone i to zone j, in millions of current dollars fob (given the way in which the data is constructed this intersection also provides the level of imports for zone j coming from zone i). Based on a detailed nomenclature, calculations for different geographic aggregates can be carried out, depending on the needs of the user. Similarly, product categories may be aggregated as required: by production "chains", by stages in the production process, or at the level of intermediate sections and sector of Industry. In the new release other aggregations can be carried out: in 4 GTAP branches, in 79 ISIC posts at 3 digits, in 35 ISIC poste at 2 digits and in 4 technological levels grouping 22 ISIC manufactured branches. The sectoral nomenclature has been chosen to provide the optimal fit with international trade and production classifications, and to minimise breaks in the series in long term analyses.