title: Strange PHP tags
body: <p>I got the code below from a tutorial that teaches how to make wordpress plugins. It has some unusual PHP tags. For example,</p>
  
  <p>a) 3rd line from the bottom, there is an opening <code>&lt;?php</code> tag. </p>
  
  <p>b) And, also, after $base_map_url  is set, there is a closing <code>?&gt;</code> tag. </p>
  
  <p>This is very different from what I've learned, yet the code works. </p>
  
  <p>c) Also, in all the plugins the author has built, there is an opening <code>&lt;?php</code> tag at the very top but not a final closing one.</p>
  
  <p>What is happening here, can you explain?</p>
  
  <pre><code>&lt;?php
  /*
   Plugin Name: Map plugin using shortcode
   Plugin URI: http://example
   Description: This plugin will get a map of whatever parameter is passed
   Author: Drew
   Version: 1.0
   Author URI: http://www.blah 
   */
  
  function smp_map_it($addr)
  {
      $addr = "1600 Pennsylvania Ave. Washington, D.C.";
      $base_map_url = 'http://maps.google.com/maps/api/staticmap?sensor=false&amp;size=256x256&amp;format=png&amp;center=';
      ?&gt;
      &lt;h2&gt;Your map:&lt;/h2&gt;
      &lt;img width="256" height="256"
          src="&lt;?php echo $base_map_url . urlencode($addr); ?&gt;" /&gt;
      &lt;?php 
  }
  
  add_shortcode('map-it','smp_map_it');
  </code></pre>