ring" minOccurs="0" /&gt;
      &lt;!-- SPDX license ID: https://spdx.org/licenses/ --&gt;
      &lt;xs:element name="license"     type="xs:string" minOccurs="0" /&gt;
    &lt;/xs:all&gt;
    &lt;!-- 'true' if file is a layer description. Default 'false' --&gt;
    &lt;xs:attribute name="isLayer"      type="xs:boolean"         use="optional" default="false"/&gt;
  &lt;/xs:complexType&gt;

  &lt;!-- Board Info --&gt;
  &lt;xs:complexType name="BoardInfoType"&gt;
    &lt;xs:simpleContent&gt;
      &lt;xs:exte