Control Points

Extrude Curve and Move

Reference

Mode:

Edit Mode

Shortcut:

E

Extrudes points by duplicating the selected points, which then can be moved, and connecting those points back to the original curve creating a continuous curve.

Tilt

Reference

Mode:

Edit Mode

Tool:

Toolbar ‣ Tilt

Shortcut:

Ctrl-T

This setting controls how the normals twist around each control point. The tilt will be interpolated from point to point (you can check it with the normals).

Clear Tilt

Reference

Mode:

Edit Mode

Shortcut:

Alt-T

You can also reset the tilt to its default value (i.e. perpendicular to the original curve plane).