Weak Gravity Conjecture as a Razor Criterium for Exotic D-brane instantons

We discuss implications of Weak gravity conjecture (WGC) for exotic D-brane instantons. In particular, WGC leads to indirect stringent bounds on non-perturbative superpotentials generated by exotic instantons, with many implications for phenomenology: R-parity violating processes, neutrino mass, $\mu$-problem, Neutron-Antineutron transitions and collider physics.