Example 1: A container, inside there is a div, a absolutely positioned div, a floated full-width div, and a clearing div (with no dimensions.) The absolutely positioned div doesn't show up.
Example 2: Same as example 1, but the floated div has margin-right:-3px
Example 3: Same as example 1, but the floated div is 600px wide. The AP box shows up when the float is at least 3px narrower than the container
Example 4: Same as example 1, but in the source code the absolute div is before the green div
Example 5: Same as example 1, but in the source code the absolute div is after the clear
Example 1b: Same as example 1, but the clearing div has a dimension.
Example 2b: Same as example 2, but the clearing div has a dimension.
Example 3b: Same as example 3, but the clearing div has a dimension.
Example 4b: Same as example 4, but the clearing div has a dimension.
Example 5b: Same as example 5, but the clearing div has a dimension.