The first four panels show a comparison between the Stokes I calculated using the unpolarized modules of PYRATE (I_total; solid black lines) with Stokes I calculated as I_⊥ + I_∥ (dashed magenta, dash-dotted red and dotted blue lines, respectively) from radiative-transfer simulations of linear polarization for different lines of sight. In the fifth panel we show a distribution of relative errors between I_total and I_⊥ + I_∥. The Stokes I between the two cases is nearly identical with only very minimal differences, indicating that no significant errors are introduced given our formalism, even for varying magnetic fields along the LOS. In the last panel we show a distribution of relative errors between the polarization fraction computed from I_⊥ and I_∥ and the polarization fraction (p′) after accounting for the “missing” or the “excess” specific intensity of radiation.