  The properties of two measures of charge fluctuations D and Delta Phi_q are
discussed within several toy models of nuclear collisions. In particular their
dependence on mean particle multiplicity, multiplicity fluctuations and net
electric charge are studied. It is shown that the measure Delta Phi_q is less
sensitive to these trivial biasing effects than the originally proposed measure
D. Furthermore the influence of resonance decay kinematics is analysed and it
is shown that it is likely to shadow a possible reduction of fluctuations due
to QGP creation.
