This checkbox is used to toggle the "Display ? checkbox for the Hard Min, Hard Max fields in the question.
In the image below, the textual min and max limits (organized - disorganized, respectively) have also been assigned numbers that differentiate among a broader range (1 - 5) categories than one or the other. In this case the designer has chosen to display the limits in all possibility to permit some 'gray-area' for a more "modest" response.