Synthetic UV line profiles in units of normalized frequency X_ν = (ν/ν₀ − 1)c/ ν_∞, and for velocity separation ν_sep/ ν_∞ = 1.35 between the line-centers of the two doublet components (which corresponds to the separation of the PV resonance doublet in a wind with ν_∞ = 2000 km s^-1). For the line-strengths and clumping parameters indicated in the panels and described in Table 1 and in text, the black lines show profiles computed using the vmSEI method developed here, the red dashed lines (two leftmost panels) show results from the standard SEI method (assuming a smooth wind), and the blue dashed lines (two rightmost panels) show results from the Monte-Carlo method by Sundqvist et al. (2010). Note that the velocity clumping factors indicated in the panels are based on the original definition Eq. (9) rather than the modified Eq. (16).