2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/133349We study a correspondence between orientation reversing involutions on compact 3-manifolds with only isolated fixed points and binary, self-dual codes. We show in particular that every such code can be obtained from such an involution. We further relate doubly even codes to Pin^- -structures and Spin-manifolds.9 pagesAlgebraic Topology57M60, 94B05, 57M50, 57R91text