title: What is the intent of inline <?=$GLOBAL?> directive in PHP? Is it markdown?
body: <p>I am working on a <a href="https://github.com/nst/Quickies" rel="nofollow">PHP project</a> that is using an (anti)-convention that is causing errors, and I'm not quite sure what it is trying to achieve, so fixing it is difficult..</p>
  
  <p>The project does use markdown, which I have included at runtime… But I can't find mention of this syntax anywhere, <a href="http://michelf.com/projects/php-markdown/extra/" rel="nofollow">including the extended documentation</a>, so, here I am.. Any ideas as to what is this syntax trying to accomplish?</p>
  
  <p>It doesn't help that the original developer used short tags (don't do that, people).. but here goes..  It is the <code>&lt;?=$PHP_SELF?&gt;</code> that is causing problems..</p>
  
  <pre><code>&lt;p&gt;[&lt;a href="&lt;?=$PHP_SELF?&gt;"&gt;categories&lt;/a&gt;] 
         [&lt;a href="&lt;?=$PHP_SELF?&gt;?index"&gt;index&lt;/a&gt;] 
         [&lt;a href="&lt;?=$PHP_SELF?&gt;?all"&gt;all (&lt;?=$notes_count?&gt;)&lt;/a&gt;] 
         [&lt;a href="&lt;?=$PHP_SELF?&gt;?latest"&gt;latest&lt;/a&gt;]&lt;/p&gt;
  </code></pre>