  We study the construction of the classical nilpotent canonical BRST charge
for the nonlinear gauge algebras where a commutator (in terms of Poisson
brackets) of the constraints is a finite order polynomial of the constraints.
Such a polynomial is characterized by the coefficients forming a set of higher
order structure constraints. Assuming the set of constraints to be linearly
independent, we find the restrictions on the structure constraints when the
nilpotent BRST charge can be written in a simple and universal form. In the
case of quadratically nonlinear algebras we find the expression for third order
contribution in the ghost fields to the BRST charge without the use of any
additional restrictions on the structure constants.

High Energy Physics - Theory