Before revision:  In the stochastic, discrete-time,  constant-coefficients case, the associated free parameters are shown to be the initial values of the impulse responses of expectation terms. These values may be completely unconstrained by the requirement of model-consistency  , yet when  appropriately specified, they determine a unique solution .
After revision:  In the stochastic, discrete-time, constant-coefficients case, the associated free parameters are coefficients that determine the public's most immediate reactions to shocks. The requirement of model-consistency , yet when appropriately specified, they determine a unique solution .