2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/44420The solution to the supersymmetric FCNC problem may not have a simple field theory interpretation. Here I advocate a possibility based on string selection rules. The requirement of non--trivial Yukawa structures restricts the form of the soft terms such that the FCNC problem often does not arise.11 pages, based on a talk given at Planck'05, 23-28 May 2005, ICTP, Trieste, ItalyHigh Energy Physics - PhenomenologyHigh Energy Physics - Theorytext