Properties for CSS Positioning

Property Values
clip shape | auto

The clipping area defines the part of the element which is visible. Auto (the default value) makes the whole element visible.

The only clipping shape allowed is a rectangle, specified by the notation rect (<top> <right> <bottom> <left>). Each of <top> <right> <bottom> <left> is either a length unit (with coordinates relative to the element's origin) or the value 'auto', which makes the element fully visible in that direction.