  The aim of this lecture is to present in a comprehensible way what the BRST
quantization means and how the "classical" master equation, action and BRST
transformations have to be prolonged towards the same "quantum" items. The
presentation will focus not only on the standard BRST symmetry, but on larger
symmetries as sp(2), both in the Lagrangean and in the Hamiltonian formalisms.
How to find answers to these questions in more sophisticated cases will be
illustrated by the example of a nonlinear system with open superalgebra.
