  A recent suggestion that vector potentials in electrodynamics (ED) are
nontensorial objects under 4D frame rotations is found to be both unnecessary
and confusing. As traditionally used in ED, a vector potential $A$ always
transforms homogeneously under 4D rotations in spacetime, but if the gauge is
changed by the rotation, one can restore the gauge back to the original gauge
by adding an inhomogeneous term. It is then "not a 4-vector", but two: one for
rotation and one for translation. For such a gauge, it is much more important
to preserve {\it explicit} homogeneous Lorentz covariance by simply skipping
the troublesome gauge-restoration step. A gauge-independent separation of $A$
into a dynamical term and a non-dynamical term in Abelian gauge theories is
re-defined more generally as the terms caused by the presence and absence
respectively of the 4-current term in the inhomogeneous Maxwell equations for
$A$. Such a separation {\it cannot} in general be extended to non-Abelian
theories where $A$ satisfies nonlinear differential equations. However, in the
linearized iterative solution that is perturbation theory, the usual Abelian
quantizations in the usual gauges can be used. Some nonlinear complications are
briefly reviewed.

General Physics;High Energy Physics - Phenomenology