You can convert a straight edge to a spline edge. You may wish to convert a straight edge to a spline edge so you can carry out modifications using the Move End Pt and Move spline point commands, which only consider spline edges.
To convert a straight edge to a spline edge,
1. Click Cabling and then, in the Modify group, click More.
2. Click Convert in the Tools section. The Convert to Spline Edge dialog box opens.
3. Select a straight edge of a cable in the viewport.
Convert in the Tools section. The Convert to Spline Edge dialog box opens.
to complete the operation.