Level</td>
      <td>A few code lists that FHIR defines are hierarchical - each code is assigned a level.
          In this scheme, some codes are under other codes, and imply that the code they are under also applies</td>
    </tr>
    <tr>
      <td>System</td>
      <td>The source of the definition of the code (when the value set draws in codes defined elsewhere)</td>
    </tr>
    <tr>
      <td>Code</td>
      <td>The code (used as the code in the resource instance)</td>
    </tr>
    <tr>
      <td>Di