The abstract global PointSetId element is the head of a substitution group. Any element that is a member of the group may be substituted for the PointSetId element anywhere the PointSetId element could be used in an instance file. The allowed substitutes are all derived from PointSetReferenceBaseType.
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="PointSetId" type="PointSetReferenceBaseType" abstract="true"><xs:annotation><xs:documentation>The abstract global PointSetId element is the head of a substitution group. Any element that is a member of the group may be substituted for the PointSetId element anywhere the PointSetId element could be used in an instance file. The allowed substitutes are all derived from PointSetReferenceBaseType.</xs:documentation></xs:annotation></xs:element>