While a NURBS object is selected and the Modify panel is active, the quad menu displays two quadrants that are specifically for NURBS editing.
These options are general display and sub-object level shortcuts.
Transform Degrade—Toggles Degradation Override.
Display Shaded Lattice, Display Lattices, Display Surfaces, and Display Curves—See Display Controls for NURBS Models.
Sub-objects—Displays the sub-object choices for the selected object, as well as a Top-level choice.
These options are creation and editing shortcuts.
Create CV Surface, Create CV Curve, Create Point Surface, Create Point Curve—These create a new NURBS sub-object.
Insert CV Row, Insert CV Column, Refine CV Curve, Refine CV Row—These add CVs to a CV Surface sub-object by inserting or refining. For the difference between inserting and refining, see Editing Surface CV Sub-Objects. See NURBS Concepts for more information about refining.