2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/49865In this note the open string partition function is analyzed carefully in a way to reveal the group-theoretical aspects. For the simple cases of ADE orbifolds with regular Chan-Paton action a prescription for consistent boundary states is given. In the process of outlining how they encode McKay correspondence, we argue that this results from a non-trivial conspiracy of numerical factors in the string amplitudes.Latex, 11 pages, no figuresHigh Energy Physics - Theorytext