  In front-form dynamics a current operator for systems of interacting
particles, which fulfills Poincar\'e, parity and time reversal covariance,
together with hermiticity, can be defined. The electromagnetic form factors can
be extracted without any ambiguity and in the elastic case the continuity
equation is automatically satisfied. Applications to the calculation of
deuteron form factors are presented, and the effects of different
nucleon-nucleon interactions, as well as of different nucleon form factors are
investigated.
