11.1 Overflow and clipping

Generally, the content of a block box is confined to the content edges of the box. In certain cases, a box may overflow, meaning its content lies partly or entirely outside of the box, e.g.:

Whenever overflow occurs, the 'overflow' property specifies whether a box is clipped to its padding edge, and if so, whether a scrolling mechanism is provided to access any clipped out content.

11.1.1 Overflow: the 'overflow' property

Value:  visible | hidden | scroll | auto | inherit
Initial:  visible
Applies to:  block containers
Inherited:  no
Percentages:  N/A
Media:  visual
Computed value:  as specified