While not directly used in defining a shape itself, there are Entry and Exit points that accompany outlines once a stitch object type has been assigned.
These Entry and Exit points indicate the preferred location of the beginning and ending of the stitching process. In the illustration, the stitching would begin at the green handle on the left, and finish up at the red handle on the right. You can drag the handles around anywhere on the outline. You cannot drag them to a hole, if the shape has one.
There are some object types where the stitching follows an algorithm that comes back to a single point. Those object types are noted in their respective sections. Entry and exit points are used to limit the number of jump stitches in a design. By having the objects end and begin at near-most points, the transition stitch between the objects is minimized.
The Entry point on an object is where the stitching will begin, and Exit is where the stitching will complete. The purpose of adjusting the entry and exit is to minimize (or eliminate) traveling runs needed to move from one object to the next. This also lowers the stitch count.
Note: Usually you will want to set the Entry and Exit points after you have sequenced your objects.
Most stitch generation has the availability of adjustable Entry and Exit points, although some only use the Exit such as Stippling, where stitching is continuous.
Entry and Exit adjustments are usually not noticeable in the resulting stitches except for Runs. Runs by definition have styles such as Single, Double, Bean, etc. When you have a single run enter and exit at the same point, you are going to have a double-run result. The exit handle forces the stitches to run to the exit, over top of what’s been stitched. This can be handy when creating redwork or running-stitch designs as you may set the Exit Handle as needed, and not worry about changing the property to a double.