  In this paper, we present a covariant formalism that connects solutions to
force-free electrodynamics in the non-null case and foliations of spacetime. In
doing so, we are also able to derive an expression of the general non-null
current density vector. Just as in the null case, solutions in the non-null
case can give rise to a dual solution, however, as is shown below, this can
happen only when the solution describes a vacuum field. All theorems are
illustrated with previously known solutions.
