title: What does a script-Tag with src AND content mean?
body: <p>Example from Googles +1 button:</p>
  
  <pre><code>&lt;script type="text/javascript" src="https://apis.google.com/js/plusone.js"&gt;
        {"parsetags": "explicit"}
  &lt;/script&gt;
  </code></pre>
  
  <p>The script Tag has a src-Attribute <strong>and</strong> content. What does this mean and how does it work?</p>