Five examples for velocity profiles of Si iii-selected absorption line systems in our HST/COS survey with decreasing Si iii λ1206 absorption strengths (gray-shaded area; from left to right). Shown are the velocity profiles of H i, Si iii, Si ii, Si iv, C ii, and C iv (from top to bottom) plotted against the absorber’s restframe velocity. The names of the background QSOs and the absorption redshifts are indicated above each panel. A complete set of velocity plots for all detected Si iii absorbers discussed in this paper is available in the Appendix.