"Forcing functions are strong constraints that can prevent inappropriate behavior." #readingToday

Forcing functions are the extreme case of strong constraints that can prevent inappropriate behavior. Not every situation allows such strong constraints to operate, but the general principle can be extended to a wide variety of situations. In the field of safety engineering, forcing functions show up under other names, in particular as specialized methods for the prevention of accidents. Three such methods are interlocks, lock-ins, and lockouts.

Design of Everyday Things Revised, Don Norman