This option is used to translate contours strings with no Z values (heights) back onto 3d data.

After selecting a known contour string with a height, the panel will automatically increase/decrease the next value to apply by the increment value added.

This removes the need to continuously type in new values and using the change in colour can help identify areas not yet covered.

To open this 12d panel, Select: User > Miscellaneous > A to C > Contour levels