The optional xId attribute is a reference to the id of a QIF object in an external document. A QIF object in an external QIF document can be referenced by using references to two QIF ids: the id of the external document reference of type ExternalQIFDocumentReferenceType found in the local document and the id of the object found in the external document.
Source
<xs:element name="HatchStyleId" type="QIFReferenceType" minOccurs="0"><xs:annotation><xs:documentation>The optional HatchStyleId element is an identifier of the hatch style for the section area.</xs:documentation></xs:annotation></xs:element>
The required n attribute is the number of Loop elements in this set.
Source
<xs:element name="Loops" type="SectionLoopsType"><xs:annotation><xs:documentation>The Loops element is a set of section closed loops - boundary of the area.</xs:documentation></xs:annotation></xs:element>
<xs:complexType name="SectionAreaType"><xs:annotation><xs:documentation>The SectionAreaType defines a section area.</xs:documentation></xs:annotation><xs:sequence><xs:element name="HatchStyleId" type="QIFReferenceType" minOccurs="0"><xs:annotation><xs:documentation>The optional HatchStyleId element is an identifier of the hatch style for the section area.</xs:documentation></xs:annotation></xs:element><xs:element name="Loops" type="SectionLoopsType"><xs:annotation><xs:documentation>The Loops element is a set of section closed loops - boundary of the area.</xs:documentation></xs:annotation></xs:element></xs:sequence></xs:complexType>