g, when nothing
          is reported to a testing log stream.
        </p>
<p>
          Log level is set to one of the predefined levels which are organized hierarchically,
          where each level includes all the messages on that level as well as all
          the messages from levels below. Levels are identified by string names,
          which are listed next.
        </p>
<h5>
<a name="boost_test.utf_reference.rt_param_reference.log_level.h0"></a>
          <span class="phrase"><a name="boost_test.