<!-- WILL match -->
<div class="module">
  <p>You're a knob</p>
</div>

<!-- WILL match -->
<aside class="country module iceland"></aside>

<!-- Will NOT match -->
<div class=".module">The dot is for CSS, not HTML</div>

<!-- Will NOT match -->
<div class="bigmodule">Wrong class</div>

.module {

  color:pink;
}