An edge is the portion of a patch object between two adjacent vertices. At the Edge sub-object level of an Editable Patch object, you can select single and multiple edges and move, rotate, and scale them using standard methods. You can also hold down the Shift key and drag an edge to create a new patch. Holding down the Shift key during edge extrusion creates a new element.
When you move an outer or boundary edge of a patch, the adjacent interior edges are normally “locked” so that they move in parallel with the boundary edge. This is often useful, because it provides a uniform transition across the patch. This default is known as Auto Interior.
Selects all edges that are used by only one patch. You can use this to troubleshoot a surface; open edges will be highlighted.
For information on the other controls in this rollout, see Selection Rollout (Editable Patch).
See Soft Selection Rollout for information on the Soft Selection rollout settings.
Modify panel 
Expand the Editable Patch entry. 