title: How to teach checkstyle to ignore my custom javadoc tags?
body: <p>I have a custom javadoc tag (<code>@todo</code>) attached to some methods and classes. This is what  <a href="http://checkstyle.sourceforge.net/" rel="nofollow">checkstyle</a> says:</p>
  
  <pre><code>[ERROR] Foo.java[0:null] Got an exception - java.lang.IllegalArgumentException: 
  the name [todo] is not a valid Javadoc tag name
  </code></pre>
  
  <p>Is it possible to teach checkstyle to ignore these tags?</p>
  
  <p>I tried to configure as specified <a href="http://checkstyle.sourceforge.net/config_javadoc.html" rel="nofollow">here</a>:</p>
  
  <pre><code>&lt;module name="JavadocType"&gt;
    &lt;property name="allowUnknownTags" value="true"/&gt;
  &lt;/module&gt;
  </code></pre>
  
  <p>But got a message:</p>
  
  <pre><code>... cannot initialize module TreeWalker - Property 
  'allowUnknownTags' in module JavadocType does not exist, 
  please check the documentation
  </code></pre>
  
  <p>Moreover, I need to use these tags not only for types, but also for packages, methods, and variables.</p>
  
  <p>ps. It's <code>maven-checkstyle-plugin</code> 2.6</p>