Diary_Overview
The Overview option displays up to six diaries (three before and two after the currently selected diary) - rather than move the diaries around so that they are grouped correctly this option can be used. You should set Diary_Overview to the diaries you want displayed e.g. Diary_Overview = 1 4 6 will always display diaries 1, 4 and 6 no matter what the currently selected diary is.