title: can we use <? insted of <?php for start of php file, if not what is the use <? at start of php
body: <p>Currently i am working with an boonex dolphin project
  inside the project soruce code many of the php file starts with <code>&lt;?</code> instead of <code>&lt;?php</code>  also i found out that in many of statements it used another statement like<code>&lt;?= $start ?&gt;</code></p>
  
  <p><code>&lt;td valign="top" align="justify"&gt;&lt;?= $str ?&gt;&lt;/td&gt;</code></p>