2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/56274In this short note we review the construction and role of Wess-Zumino couplings of Dirichlet branes and Orientifold planes, and show how these combine to give the Green-Schwarz anomaly cancelling terms.4 pages, LaTeX. To appear in the gong show section of the Proceedings of the Cargese `99 ASI "Progress in String Theory and M-Theory"High Energy Physics - Theorytext