Some remarks on exotic mesons

The fact that gluons carry color charge, makes the assumption of bound states of gluons, ggg, a fundamental prediction from quantum chromodynamics (QCD). Despite the search for these exotic mesons have revealed the existence of a large number of candidates, the unambiguous identification remains unsolved. The most recent experimental measurements in pp, πp, and p-p interactions, from several experiments at FNAL, BNL and CERN, have accumulated strong evidences of some well established candidates to exotic mesons. In this paper the experimental situation for the search for exotic mesons is discussed. The paper outline the experimental difficulties in the field and emphasizes the importance for QCD of the unambiguous identification of such exotic mesons. The paper emphasizes also the importance of the most recent and new measurements coming from experiments with high statistics in gluon-rich channels. (Author)