>
        optional
       </td>
       <td>
       </td>
      </tr>
      <tr>
       <td>
        22
       </td>
       <td>
        onlineDescriptorList
       </td>
       <td>
        <code>
         list&lt;
         <code>
          string
         </code>
         &gt;
        </code>
       </td>
       <td>
        This field specifies a list of descriptors from a normalized controlled
vocabulary that correspond to topics mentioned in the article.
        <br/>
        Examples Include:
        <