  This work presents a review of the Standard Model sources of backgrounds to
the search of supersymmetry signals. Depending on the specific model, typical
signals may include jets, leptons, and missing transverse energy due to the
escaping lightest supersymmetric particle. We focus on the simplest case of
multijets and missing energy, since this allows us to expose most of the issues
common to other more complex cases. The review is not exhaustive, and is aimed
at collecting a series of general comments and observations, to serve as
guideline for the process that will lead to a complete experimental
determination of size and features of such SM processes.
