  Over the past 60 years a rich sample of experimental results concerning the
inclusive production of $\pi^-$ mesons has been obtained spanning a range from
about 3 GeV to 13 TeV in interaction energy. This paper attempts a
model-independent overview of these results with the aim at obtaining an
internally consistent data description on a dense grid over the three inclusive
variables transverse momentum, rapidity or Feynman $x_F$ and interaction
energy. The study concentrates on the non-perturbative sector of the strong
interaction by limiting the transverse momenta to $p_T <$ 1.3 GeV/c. The
three-dimensional interpolation which is mandatory and necessary for this aim
is shown to provide a controlled systematic precision of better than 5%. This
accuracy allows for a critical inspection of each of the 40 experiments
concerned in turn. It also allows precision tests of some of the physics
concepts developed around inclusive processes like energy scaling, "thermal"
production and the evolution of transverse momenta.
