Scale invariant presentation of inclusive spectra in terms of light front variables is proposed. The variables introduced go over to the well-known scaling variables x F = 2p z / √ s and x T = 2p T / √ s in the high p z and high p T limits respectively.Some surface is found in the phase space of produced π ± -mesons in the inclusive reaction pp → π ± X at 22.4 GeV/c, which separates two groups of particles with significantly different characteristics. In one of these regions a naive statistical model seems to be in a good agreement with data, whereas it fails in the second region.Classification codes: PACS numbers: 13.85 Ni, 13.90+i