2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/176600We discuss several aspects of higher dimensional models that contain bulk gauge and fermion fields only. In particular we argue that non-standard boundary conditions involving charge-conjugate fermion fields offer attractive model building possibilities. We also discuss a no-go theorem for 5-dimensional models which severely limits their phenomenological relevance.4 pages, 1 fugure; contribution to the SUSY06 proceedingsHigh Energy Physics - PhenomenologyHigh Energy Physics - Theorytext