Normally a Descendant Plan will expand all childrens' families with their children until the specified number of generations is reached. In the dialogue if the family descent combi box is used to select an ancestors' plan (say from yourself or your children) then only those descendants on that that blood line will be expanded, so that the siblings will be shown with their spouses but no children to clutter your descent. The first diagram shows the layout with the number of lines of text, ready to view three pages across in detail. In this case, there were two red blood lines from two sons at the top to a couple 9=9 who married near the bottom. Note that the diagram below is for planning purposes only.
The second example below shows a Tall Tree made from an Ancestors' Plan where the Family Descent was selected from a previously made descendants plan from an ancestor with all generations down to the person selected as the start of the new ancestors plan. This will restrict the ancestral search to the line of descent from that ancestor, without showing all side lines. In this case, there were two red blood lines back to two sons of John Smith and Margaret Redland in Tankerness, Orkney.