With the exception of a menu structure, which always appears at the top of the structure chart, the structure chart displays the relative Z-Order of each object in the layout with the top-most object having the lowest Z-Order and the bottom-most object the highest Z-Order. An object's Z-Order is its relative position in the third dimension (i.e. into the screen), and hence determines which objects overlay one another if they intersect in the screen's X-Y plane. An object that is owned by another object inherits its owner's Z-Order with respect to all sibling objects of its owner. However, with respect to its own sibling objects, the Z-Order as described above takes effect.
The Z-Order for menus is interpreted differently. If a menu exists, the icon that represents the menu bar is always at the top of the structure chart. The tree structure of menu items connected to it is interpreted as follows. The menu item directly connected to the menu bar icon appears on the menu bar. The sequence in which they appear on the bar corresponds as top-to-bottom in the structure chart with left-to-right on the menu bar. To rearrange items on the bar, move the icons which represent them either higher up or lower down in the structure chart. The reverse is true for menu items in a list. Left-to-right in the structure chart corresponds to top-to-bottom in the list. To rearrange items in a list, move the icons which represent them either further to the left or to the right as required. When a menu item is moved, all the menu items which it owns are moved with it (i.e. a menu item always retains its child menu items). You can move entire menu item sub-trees from one owner to another.