Plan delineations are specific delineations engineers use to illustrate structure or portion of structure. A plan is drawn from a vertical airplane looking down from over. This is as if you sliced through a space horizontally and stood overlooking down on it. Plans are a common design delineation and specialized architectural or engineering convention for graphic representation of armature. Except plan perspectives, plan delineations are orthographic protrusions. This means they are not drawn in perspective and there is no foreshortening.