title: Why do local variables in Magento have an underscore prefix?
body: <p>As a follow up to <a href="https://stackoverflow.com/questions/3900756/magento-when-to-pass-variables-to-a-block-and-when-not-to">an earlier question</a> I wonder if anyone knows why Magento templates all declare their variables with an underscore. Templates are .phtml files <code>include</code>-ed from <code>Mage_Core_Block_Template::fetchView()</code>, their local variables are disposed of by the end of the function and never become global. </p>
  
  <p>So what's the point of an underscore?</p>