If the classname has a colon, it's SimpleData.
Properties apply to the closest ancestor that has a SimpleData classname:
<ul>
<li class="audio:album">
<span class="artist">Nirvana</span> - <span class="title">Nevermind</span>
</li>
<li class="audio:album">
<span class="artist">Sigur Rós</span> - <span class="title">Með suð í eyrum við spilum endalaust</span>
</li>
</ul>
Properties with 'of:' classnames apply to the SimpleData element with that id:
<p>The album <span class="audio:album" id="abc123">Nevermind</span>
by <span class="artist of:abc123">Nirvana</span> has the following tracks:</p>
<ol class="tracks of:abc123">
<li class="track">AAAAA</li>
<li class="track">BBBBB</li>
<li class="track">CCCCC</li>
</ol>
The SimpleData root should be on a link, where possible:
<p><span class="artist of:abc123">Nirvana</span>'s album
<a class="audio:album" id="abc123" href="http://en.wikipedia.org/wiki/Nevermind">Nevermind</a> was released in 1991.</p>
An event example:
<ul>
<li class="cal:2008-01-09">
<a class="title" href="http://events.com/event/12324">New Kids on the Block</a>
<div class="when">January 9th 2008, 6pm</div>
<div class="address">Astoria, London<div>
</li>
</ul>