They are tools for linking classifications by establishing a relationship between categories of two or more thereof, which may be of the same or different nature. They enable converting compiled data from a classification in terms of another, making their structures and contents equivalent. In order to provide efficient, timely and accurate information systems that enable the comparison of statistics at a national, regional and international level, DANE, develops correspondence tables that link different types of classifications for performing various analyzes and that are aimed at the generation of indices.