title: Can a single XML element have multiple values?
body: <p>A product can comply with <em>zero or several</em> standards, eg STD1, STD2, STD3.</p>
  
  <p>The XML has a optional field, let's call it <code>complies</code>.</p>
  
  <p>Can I make something like that? (Here I use a comma.)</p>
  
  <pre><code>&lt;complies&gt;STD1,STD3&lt;/complies&gt; or &lt;complies&gt;STD2&lt;/complies&gt;
  </code></pre>
  
  <p>And how can I define this XSD type?</p>