<!DOCTYPE html><p>According to the 2010 WD of CSS 2.1, there should be no red on this page. Under a more natural criterion of when clearance is needed, there would be 20px of red separating two green squares.</p> <div style="float:left; width:100px; height:100px; background:green; border-bottom:20px solid red; margin-bottom:-20px"></div>
<div style="height:20px; background:gray"></div>
<div>
<div style="clear:left; margin-bottom: 100px">
<div style="float:left; width:100px; height:100px;
background:green"></div>
</div>
</div>According to the 2010 WD of CSS 2.1, there should be no red on this page. Under a more natural criterion of when clearance is needed, there would be 20px of red separating two green squares.
