title: phpDocumentor - List of available values for constant
body: <p>I am writing API client and I want to define default value for one parameter via constant. Now I have it like this:</p>
  
  <pre><code>/**
   * Available: val_1|val_3|val_3|val_4|val_5
   * 
   * @var string
   */
  const MY_DEFAULT_VALUE = 'val_1';
  </code></pre>
  
  <p>But I am not sure if this usage of "enum" is correct. I found how to <a href="https://stackoverflow.com/questions/6476888/phpdocumentor-how-to-document-available-options-for-string-parameter">do it with method parameters</a>, but this is not the same problem. Definition of my method is:</p>
  
  <pre><code>public function callApi($someParam, $anotherParam = self::MY_DEFAULT_VALUE)
  </code></pre>
  
  <p>Is there any standard about this? Thanks a lot.</p>
  
  <p><strong>EDIT:</strong> I will stop using abstract values and parameters and I'll try to explain it on specific example which I am solving... I am calling API with method <code>setLanguage()</code> which has optional parameter <code>$lang</code>. Snippet of my code:</p>
  
  <pre><code>const DEFAULT_LANGUAGE = 'ENG';
  // ...
  public function setLanguage($lang = self::DEFAULT_LANGUAGE)
  </code></pre>
  
  <p>But API, which I am calling, accept only some languages. Basicaly, what I want to tell to other programmers in comment is: "<em>Ok, so you want to change default language, but note that only these values are valid.</em>". This is nothing critical and I think my currect solution is clear enough too:</p>
  
  <pre><code>/**
   * Available: ENG|ITA|FRA|DEU|ESP
   * 
   * @var string
   */
  const DEFAULT_LANGUAGE = 'ENG';
  </code></pre>
  
  <p>I was just wondering, if there is some "good practice" about this.</p>