 nillable="true"&gt;
    &lt;xs:complexType&gt;
      &lt;xs:all&gt;
        &lt;!-- project info --&gt;
        &lt;xs:element name="info"           type="InfoType"         minOccurs="1" /&gt;
        &lt;!-- board info --&gt;
        &lt;xs:element name="board"          type="BoardInfoType"    minOccurs="0" /&gt;
        &lt;!-- tool info --&gt;
        &lt;xs:element name="created"        type="CreationInfoType" minOccurs="0" /&gt;
        &lt;!-- optional: project layers --&gt;
        &lt;xs:element na