2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/216978We define the notion of a Catalan pair (which is a pair of binary relations (S,R) satisfying certain axioms) with the aim of giving a common language to most of the combinatorial interpretations of Catalan numbers. We show, in particular, that the second component R uniquely determines the pair, and we give a characterization of R in terms of forbidden configurations. We also propose some generalizations of Catalan pairs arising from some slight modifications of (some of the) axioms.26 pages, 14 figuresCombinatorics06A07, 05A15text