  We discuss how one can identify CP violation (and conservation) in
multi-Higgs-doublet potentials. After a brief review of CP violation in the
2HDM, we refer to the fact that for NHDM with $N \geq 3$ the well known methods
useful in the case $N = 2$ have not been generalized in order to provide a set
of well defined necessary and sufficient conditions for CP conservation. We
then present a simple method, proposed by the authors, to be used in such
cases. Two non-trivial examples based on an $S_3$-symmetric three-doublet model
are analyzed by means of this new method.
