Example of multi component decomposition of the C iv (left) and C iii] (right) line profiles (Sect. 2.1) after continuum and Fe ii subtraction. The narrowest component of the line (NC) is displayed with a dotted-red line, the broad component (BC) with a dashed-blue line, the very broad component (VBC) of C iii] and the absorber in front of C iv are shown in green dot-dashed. The sum of the individual components, corresponding to the line model, is shown with a solid grey line. Characteristics of the components are provided in Table 2.