This paper describes the basis for assigning and implementing a model uncertainty for the Valencia RPA multi-nucleon effect. The analysis of neutrino data in Rodrigues et al. makes clear the need for an RPA effect, especially describing the suppression at very low momentum transfer. That published analysis does not constrain the magnitude of the effect; it only tests models with and without the effect against the data. Other MINERvA analyses need an expression of the model uncertainty in the RPA effect. A well-described uncertainty can be used for systematics for unfolding, for model errors in the analysis of non-QE samples, and possibly even as input for fitting exercises for model testing or constraining backgrounds. This prescription follows closely the one used by T2K and would be a suitable starting point for NOvA and possibly even DUNE.
