title: How is the caret on Twitter Bootstrap constructed?
body: <p>This is more of a curiosity question than something I really need to know.</p>
  
  <p>On this page:</p>
  
  <p><a href="http://twitter.github.com/bootstrap/components.html#buttonDropdowns" rel="noreferrer">http://twitter.github.com/bootstrap/components.html#buttonDropdowns</a></p>
  
  <p>How is the little caret / down arrow thing constructed? Poking around with Firebug it looks like it's just made with transparent borders but ... I must be missing something.</p>
  
  <p>Bootstrap is very cool. I just got it going with Symfony.</p>