title: Why do PHP error messages contain a link to the name of the name of the function in their HTML representation?
body: <p>Why do PHP error messages contain a link, such as this error:</p>
  
  <p><code>&lt;b&gt;Warning&lt;/b&gt;:  preg_match_all() [&lt;a href='function.preg-match-all'&gt;function.preg-match-all&lt;/a&gt;]: Delimiter must not be alphanumeric or backslash in &lt;b&gt;/home/www/test.php&lt;/b&gt; on line &lt;b&gt;93&lt;/b&gt;&lt;br /&gt;</code></p>
  
  <p>with this link?:</p>
  
  <p><code>[&lt;a href='function.preg-match-all'&gt;function.preg-match-all&lt;/a&gt;]</code></p>
  
  <p>Is the assumption that PHP will be configured to put a <code>http://www.php.net/</code> in front of that URL?  Or that a person will have a copy of the PHP documentation on their web server and that by clicking on that link they will be able to access information about the function?</p>
  
  <p>This is just something I've been curious about since it seems that unless the error occurred on php.net, such a link would be useless.</p>
  
  <p>I know it's possible to set up custom error handlers, etc.  My question is: Why is this the default behavior of PHP?</p>
  
  <p>Thanks.</p>