Effect of modified treatments of acceleration by line and photoionization transitions on occupation numbers of Fe v and Fe vi superlevels (T_eff = 56 000 K, log g = 7.9). The six panels show: 1. Original treatment of bb and bf transitions. 2. New treatment of bf transitions. 3. Difference between the first two. 4. New procedure for bb transitions. 5. bf and bb refinements are implemented. 6. Difference between the last two. The legend in panel 1 refers to the superlevel designations.