  The variety of ideas put forward in the context of a "composite" picture for
the Higgs boson calls for a simple and effective description of the related
phenomenology. Such a description is given here by means of a "minimal" model
and is explicitly applied to the example of a Higgs-top sector from an SO(5)
symmetry. We discuss the spectrum, the ElectroWeak Precision Tests, B-physics
and naturalness. We show the difficulty to comply with the different
constraints. The extended gauge sector relative to the standard SU(2)xU(1), if
there is any, has little or no impact on these considerations. We also discuss
the relation of the "minimal" model with its "little Higgs" or "holographic"
extensions based on the same symmetry.

High Energy Physics - Phenomenology