The Working Plan tool helps locate objects being drawn in a 3D view by restricting the drawing action to a specified story. Designating a particular story level as the Working Plane is accomplished using the Working Plane drop-down list that displays in the lower right-hand corner of a 3-D View display window when a drawing command is active.
With the Working Plane identified, the objects drawn in the 3-D view will be restricted to that Plane, unless snaps are used. This feature is intended to ensure that objects being drawn in a 3D View lie on the intended plane, which can be difficult to accomplish in a 3D view.
If the story selected in the Working Plane drop-down list has other stories that have been identified as being Similar to it and the Similar Stories drop-down list is set to Similar Stories, the objects drawn in the Working Plane will be replicated on the stories similar to the story selected in the Working Plane drop-down list.