  The indirect evidence for gluonic objects in gluon jets is recalled, more
accurate tests at the LHC are possible. Estimates of gluonic and quarkonic
components of scalar mesons are presented, which could be improved by further
studies, in particular of B and B_s decays. The results are consistent with the
scalar glueball mixing into f_0(500) and f_0(1500). The study of symmetry
relations for 2-body decay rates of charmonium \chi_c is suggested as crucial
test in the identification of q\bar q multiplets and glueballs. Further related
results are discussed in the recent review \cite{Ochs:2013gi}.
