Multiple Inheritance
Inheritance occurs in two different ways in O-O HTML. One way is in the definition of classes in RDF Schema, and is pretty much what you would expect in any Object-Oriented class typing scheme. The other is a bit unusual in that each element that appears in a HTML document may instantiate more than one class.Legacy Support
An important variation of this support for multiple classes in an element's class attribute is when the class name is not mapped by eRDF. While those "classes" are not recognized by eRDF, they occur frequently as legacy code, especially for CSS. The short story on this is that it is _not_ necessary to _replace_ existing class names if the old names are needed because you can just add on the new eRDF class name.<span class="sitetitle dc-title">Semantic Planet</span>
MI Examples
<img style="float: right" src="http://purl.org/NET/iand/depiction" class="foaf-depiction -foaf-Image" alt="A picture of me"/>
<span class="foaf-knows rel-parentOf -foaf-Person bio-child" id="kier"><span class="foaf-name">Kier</span></span>
<a href="http://iandavis.com" rev="dc.creator foaf.topic foaf.maker" rel="foaf.made foaf.homepage foaf-isPrimaryTopicOf">My personal home page</a>