Iteration behavior of the maximum absolute relative change in mean intensity (max | δJ/J |) for the five-level Mg ii model atom with the k and the h lines treated in PRD in the FAL-C model atmosphere. Initial level populations are initialized to LTE populations (top row) or initialized using the zero-radiation approximation (bottom row). Red markers indicate a positive maxδJ/J, and blue markers indicate a negative value. Gray lines connect values of successive PRD subiterations within one ALI-iteration. The number of PRD subiterations ranges from one to four (panels from left to right).