/em></span>
        is the name of a character class, shall match any character not in that class.
      </p>
<p>
        The following are supported by default:
      </p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead><tr>
<th>
                <p>
                  Escape sequence
                </p>
              </th>
<th>
                <p>
                  Equivalent to
                </p>
              </th>
</tr></thead>
<tbody>
<tr>
<td>
             