Representing a class' properties ala <classname>

I'm trying to document a series of classes, including their methods and 
properties.  I can refer to the classes and methods using 
<classname>foo</classname> and <methodname>bar</methodname>, but there 
doesn't appear to be an equivilant element for describing the properties 
of an object.

Any suggestions on how I can describe this?

Thanks.