Class
Expression Studio 3.0
Matches the class property of the specified element.
For example, the following style rule matches any H2 element whose class property has been assigned a space-separated list of values that include the pastoral and marine class names. This rule matches when class="pastoral aqua marine" but does not match when class="pastoral blue":
<style>
h2.pastoral.marine {color: lightseagreen;}
</style>
This selector is defined in Cascading Style Sheets (CSS), Level 1 (CSS1).