Close-up of the region between 1210 or 1220 and 1230 Å, for model d10v. In addition to the “standard” spectra from  FASTWIND and  CMFGEN (with v_mic = 15 km s⁻¹, as in Fig. 11), we display results from a  FASTWIND formal solution with v_mic = 5 km s ⁻¹, and two further sets where specific lines have been discarded from the formal solution in  CMFGEN, namely either all Fe IV lines, or all transitions (i.e., from all elements) between energy levels that are predicted, but not observationally identified. For color coding, see legend. All spectra have been calculated with an intrinsic resolution of 0.01 Å or better. In the upper panel, they have been convolved with v sin i = 200 km s⁻¹, as in Fig. 11, whereas in the lower ones no broadening has been applied.