TIWCGJQMListViewOptions.AutoDividersSelector Property
By default, the text used to create dividers is the uppercased first letter of the item's text. Alternatively you can specify divider text by setting the autodividersSelector option on the listview programmatically.
published property AutoDividersSelector: TIWCGJSonFunc index 14 read GetFuncValue write SetFuncValue stored IsFuncStored;