title: What are invalid characters in XML
body: <p>I am working with some XML that holds strings like:</p>
  
  <pre><code>&lt;node&gt;This is a string&lt;/node&gt;
  </code></pre>
  
  <p>Some of the strings that I am passing to the nodes will have characters like <code>&amp;</code>, <code>#</code>, <code>$</code>, etc.:</p>
  
  <pre><code>&lt;node&gt;This is a string &amp; so is this&lt;/node&gt;
  </code></pre>
  
  <p>This is not valid due to <code>&amp;</code>.</p>
  
  <p>I cannot wrap these strings in CDATA as they need to be as they are. I tried looking for a list of characters that cannot be put in XML nodes without being in a CDATA.</p>
  
  <p>Can someone point me in the direction of one or provide me with a list of illegal characters?</p>