It looks like 2.6.1 c "when arranging running heads and page numbers together on the same horizontal line, the space between the running head and the page number should be double or one and a half times the character size of the running head" contradicts Fig. 2.48(f) and Fig. 2.49(b), where the heads are centered. The "double or one and a half" rule should apply only when both the head and the page number are similarly aligned (e.g. both are left-aligned on the left page).