When a containing block has a specified width (e.g. "width: 335px;"), its float (if sufficiently long, tall) must extend outside and below and the text of its next sibling must be "pushed aside".

Some sample text in the first paragraph. It has a floating image that was right about here (X) in the source. However, the image is so large that it extends below the text of this paragraph.

The second paragraph is therefore also affected. Any inline boxes in it are "pushed" aside" as they are forbidden from coming inside the area delimited by the floating image's margins. Note that the pargraph boxes are still rectangular, but their borders and backgrounds are "clipped" or interrupted by the floating image.

Expected results when setting paragraphs' width to 335px (screenshot from W3C CSS 2.1):
[D]