Large current densities can be present at the plasma edge in ELMy H-modes, from ohmic, bootstrap, Pfirsch-Schlüter and diamagnetic components, in toroidal and poloidal directions. If during an ELM the edge flux surfaces of the plasma peel-off, there would be a sudden reduction in plasma toroidal current, amongst other quantities. The externally controlled poloidal field coils can not react in the time-scale of the ELM event, and in consequence the X-point and strike points would jump upwards (in the case of a lower X-point), in a fast time scale, such as the time for direct flow of particles along open field lines. Peeling is fundamentally different from the change in equilibrium that would be derived simply from a reduction in poloidal beta, in the usual "transport model" of the ELM. In that model, the flux surfaces are assumed unaltered, but transport coefficients are increased suddenly at the plasma edge. The strike points would then move in the transport time scale. Special experiments were designed to test this hypothesis: large, infrequent ELMs provide the best target plasmas, minimizing temporal and spatial resolution diagnostic problems.