   <li>
        The <b>Req</b> column is a Y/N value indicating whether the assertion is for a feature which is required. Note
        however that the feature may only be required if another feature is also used or in a particular context, as
        indicated in the <b>Context</b> column.
      </li>
      <li>
        An entry in the <b>Context</b> column indicates that the "required" status of this feature depends on the use of
        other features. If the context is itself optional, then the value of