Hand in hand with overflow: goes clip:. It also works with block level elements.

With clip one can define how much of an element gets clipped. The element has to have the overflow property set to something else than 'visible'. Also I noticed that the position property has to be set to: position:absolute;

clip:rect(20px, 400px, 50px, 15px);

has these parameters: clip:<shape>(<top>, <right>, <bottom>, <left>), where <top> and <bottom> specify offsets from the top border edge of the box, and <right>, and <left> specify offsets from the left border edge of the box in left-to-right text and from the right border edge of the box in right-to-left text. Authors should separate offset values with commas.

The only shape that is working right now is 'rect'.