2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/45738We introduce general selection rules arizing from flux-tube dynamics with non-relativistic and adiabatic quark motion, without employing model-dependent assumptions. Specifically, we indicate under which circumstances hybrids with an arbitrary degree of flux-tube excitation can disguise themselves by not decaying to S--wave states.3 pages, Postscript, revised version of talk presented at HADRON95High Energy Physics - Phenomenologytext