E.classname

Matches the element E with the class attribute "classname" (source: W3C).

HTML:

1. <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</p>
2. <p class="teasertext">Lorem ipsum dolor sit amet, consectetur adipisicing elit.</p>

CSS:

1. p.teasertext{font-weight:bold}

Output:

In the example, the second paragraph should be in bold text.