on is printed. Here, <tt>'/'</tt>
  before the rule name flags a successful match while <tt>'#'</tt> before the rule
  name flags an unsuccessful match.</p>
<p> The following are synonyms for <tt>BOOST_SPIRIT_DEBUG_NODE</tt></p>
<ol>
  <li>BOOST_SPIRIT_DEBUG_RULE</li>
  <li>BOOST_SPIRIT_DEBUG_GRAMMAR</li>
</ol>
<a name="spirit_trace_node_p__flag_"></a>
<h3>BOOST_SPIRIT_DEBUG_TRACE_NODE(p, flag)</h3>
<p> Similar to <tt>BOOST_SPIRIT_DEBUG_NODE</tt>. Additionally allows selective debugging.
  This is useful in