title: Saving an escape character 0x1b in an XML file
body: <p>We have an application that communicates with printers using their internal printer fonts. This requires sending some data in a binary format using a font description property.</p>
  
  <p>One of the characters to be sent is an escape character (0x1b). The state of the system and all options changed are later saved in an XML file, but when we try to write the value, we get the following exception:</p>
  
  <pre><code>System.InvalidOperationException: There is an error in XML document (1009, 26). ---&gt; System.Xml.XmlException: '[Some small backwards arrow symbol]', hexadecimal value 0x1B, is an invalid character.
  </code></pre>
  
  <p>I'm not really sure why this arrow functions as escape, but it works on the printer. The error occurs when we try to save it in an XML file. Any suggestions?</p>