In the 1960’s-1980’s high quality secondary beams became available at proton synchrotrons of increasing energies (PS, AGS, IHEP, FNAL, SPS). The secondary charged hadron beams contained the six stable or quasi stable charged particles π, K, p, p. The main experimental lines of research were: i) total hadron–hadron (hh) cross section measurements at high energies (plab > 20 GeV/c); ii) elastic h...