1<documentation title="Including Code">
2    <standard>
3    <![CDATA[
4    Anywhere you are unconditionally including a class file, use <em>require_once</em>. Anywhere you are conditionally including a class file (for example, factory methods), use <em>include_once</em>. Either of these will ensure that class files are included only once. They share the same file list, so you don't need to worry about mixing them - a file included with <em>require_once</em> will not be included again by <em>include_once</em>.
5    ]]>
6    </standard>
7    <standard>
8    <![CDATA[
9    Note that <em>include_once</em> and <em>require_once</em> are statements, not functions. Parentheses should not surround the subject filename.
10    ]]>
11    </standard>
12    <code_comparison>
13        <code title="Valid: used as statement">
14        <![CDATA[
15require_once 'PHP/CodeSniffer.php';
16        ]]>
17        </code>
18        <code title="Invalid: used as function">
19        <![CDATA[
20require_once<em>(</em>'PHP/CodeSniffer.php'<em>)</em>;
21        ]]>
22        </code>
23    </code_comparison>
24</documentation>
25