Panel Display Order
From HLKitWiki
[Context: HL Kit … Basic Concepts and Terminology … Manipulation of Visual Elements]
All of the panels shown within HL are assigned a specific order by the data file author. This is accomplished via the "order" attribute on each panel. The attribute specifies a numeric value that indicates the sequence in which the panel should be shown. All panels are sorted based on the order attribute they are assigned.
The resulting sorted order is then used as the sequence in which the panels are actually presented. The tabs across the top of the main window are shown in this order.
Summary panels are always shown after the edit panel, in a separate grouping. They are sequenced in the order dictated by the attribute each is assigned.