Stokes V/I profiles as a function of wavelength, shown in a range centered on the D₂ and calculated in the presence of vertical (θ_B = 0°) magnetic fields of 5 G (left panel) and 25 G (right panel). The black curves represent the results of RT calculations considering a two-term atomic model with HFS. The red curves represent calculations in which, additionally, all components of the radiation field tensor other than were set to zero, which effectively suppresses atomic level polarization fully (see text).