title: What is a "surrogate pair" in Java?
body: <p>I was reading the documentation for <code>StringBuffer</code>, in particular the <a href="http://download.oracle.com/javase/6/docs/api/java/lang/StringBuffer.html#reverse()">reverse()</a> method. That documentation mentions something about <em>surrogate pairs</em>. What is a surrogate pair in this context? And what are <em>low</em> and <em>high</em> surrogates?  </p>