Customizing Nuke with Gizmos - Nuke 101: Professional Compositing and Visual Effects - page 522

Now for the Title Safe area Knob:
15. Choose Width/Height Knob from the Add button/menu.
16. Namethis titleSafe andlabelit titleSafe .IntheTooltipfield,enter Controlsper-
centage of Title Safe Area . Click OK.
Have a look at the User Knob panel. You now have four items in it. Move the
User Knob panel a little if necessary to see the actual Properties panel ( FIGURE
12.40 ) .
Figure 12.40. The order of Knobs in the User Knobs panel is repeated in the
Properties panel.