In this short note we show, at the level of action principles, how the
light-cone action of higher spin gauge fields can easily be obtained from the
BRST formulation through the elimination of quartets. We analyze how the
algebra of cohomology classes is affected by such a reduction. By applying the
reduction to the Poincare generators, we give an alternative way of analyzing
the physical spectrum of the Fronsdal type actions, with or without trace
condition.Comment: 13 pages Latex file, Proceedings of the Workshop "Quantum Field
Theory and Hamiltonian Systems'', Caciulata, Romania, 16 - 21 Oct, 2004; more
references added, acknowledgments correcte
