The listed objects can be selected with the <SPACE>-key or by a mouse-click, if the <CTRL> key is pressed while clicking (selected objects appear red). Objects can be selected from Cross Section window or from any list in this dialog.

The row that is currently selected in upper list is active row and represents active construction line.

Upper list shows construction line name, type (axis, parallel line, ...) and total number of objects that reference to an active construction line.

Every list has thin colored line above the list header. It is a hint how considered construction lines are drawn in cross section window. Active construction line from upper list is shown with blue color. Similar (with other colors) is done for other two lists.

Walking between parents and children can be done by double-clicking row of bellow lists. For example if we want to see what are dependent construction lines of given construction line in base line list, then double-click at construction line in left bottom list activates that construction line in upper list (it becomes active construction line) and bottom lists are updated with new information. In this way "walking" through dependencies graph can be easily achieved. Such walking can be combined with multi-selection of construction lines within the same dialog.