  In the light-front form of field theory, boost invariance is a manifest
symmetry. On the downside, parity and rotational invariance are not manifest,
leaving the possibility that approximations or incorrect renormalization might
lead to violations of these symmetries for physical observables. In this paper,
it is discussed how one can turn this deficiency into an advantage and utilize
parity violations (or the absence thereof) in practice for constraining
effective light-front Hamiltonians. More precisely, we will identify
observables that are both sensitive to parity violations and easily calculable
numerically in a non-perturbative framework and we will use these observables
to constrain the finite part of non-covariant counter-terms in effective
light-front Hamiltonians.
