Interesting CSS trick

The HTML
<john>Sample text for the "john" tag</john>

<tom>Here is the "tom" tag</tom>

<bobi>Sample text for "bobi" tag</bobi>


The CSS
body {
margin:0;
padding:0;
width:760px;
margin-left:auto;
margin-right:auto;
margin-top:0;
margin-bottom:0;
}

#wrapper {
position:absolute;
height:100%;
background-color:#CCCCCC;
width:760px;
}
#footer {
position:absolute;
bottom:0;
width:760px;
height:25px;
font-size:10px;
background-color:#FFFFCC;
color:#003366;
}
john {
background-color:#333333;
color:#FFFFFF;
}
tom {
font-weight:bold;
}
bobi {
text-decoration:line-through;
}


Note: Works with Firefox and Opera. Doesn't work in IE