PHP coding standard
<p>I am checking this PHP quality control tool: <a href="http://pear.php.net/manual/en/package.php.php-codesniffer.intro.php" rel="nofollow">PHP_CodeSniffer</a></p>

<p>In its documentation page Example Section, it shows Usage of the tool:</p>

<pre><code> $ phpcs /path/to/code/myfile.php

 FILE: /path/to/code/myfile.php
 --------------------------------------------------------------------------------
 FOUND 5 ERROR(S) AFFECTING 2 LINE(S)
 --------------------------------------------------------------------------------
   2 | ERROR | Missing file doc comment
  20 | ERROR | PHP keywords must be lowercase; expected "false" but found "FALSE"
  47 | ERROR | Line not indented correctly; expected 4 spaces but found 1
  51 | ERROR | Missing function doc comment
  88 | ERROR | Line not indented correctly; expected 9 spaces but found 6
 --------------------------------------------------------------------------------
</code></pre>

<p>on line 2</p>

<blockquote>
  <p>20 | ERROR | PHP keywords must be lowercase; expected "false" but found "FALSE"', my question is why lower case "false" and "true".</p>
</blockquote>

<p>according to PHP's documentation: <a href="http://php.net/manual/en/language.types.boolean.php" rel="nofollow">"A boolean expresses a truth value. It can be either TRUE or FALSE"</a></p>
