2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/103585We define {\em incidence matrices} to be zero-one matrices with no zero rows or columns. A classification of incidence matrices is considered for which conditions of symmetry by transposition, having no repeated rows/columns, or identification by permutation of rows/columns are imposed. We find asymptotics and relationships for the number of matrices with $n$ ones in these classes as $n\to\infty$.updated and slightly expanded versionCombinatoricstext