“…Charm's first time was the discovery of the J/ψ [3,4], which followed three years after the possible first observation of an open charm decay in cosmic ray showers [5]. This discovery confirmed the existence of a fourth quark as expected by the GIM mechanism [6] motivated by the non-existence of flavour-changing neutral currents [7,8] in conjunction with the observation of the mixing of neutral kaons [9,10,11]. The second time charm attracted considerable attention was caused by the observation of D sJ states, [12,13,14,15] which could not be accommodated by QCD motivated quark models [16,17,18,19,20].…”