  We review the formulation of the Minimal Flavour Violation (MFV) hypothesis
in the quark sector, as well as some "variations on a theme" based on smaller
flavour symmetry groups and/or less minimal breaking terms. We also review how
these hypotheses can be tested in B decays and by means of other
flavour-physics observables. The phenomenological consequences of MFV are
discussed both in general terms, employing a general effective theory approach,
and in the specific context of the Minimal Supersymmetric extension of the SM.
