The id attribute is the QIF id of the datum definition, used for referencing.
Source
<xs:element name="DatumDefinition" type="DatumDefinitionType" maxOccurs="unbounded"><xs:annotation><xs:documentation>Each DatumDefinition element gives information about a datum.</xs:documentation></xs:annotation></xs:element>
The required n attribute is the number of datum definitions in the list.
Source
<xs:complexType name="DatumDefinitionsType"><xs:annotation><xs:documentation>The DatumDefinitionsType defines a list of datum definitions.</xs:documentation></xs:annotation><xs:sequence><xs:element name="DatumDefinition" type="DatumDefinitionType" maxOccurs="unbounded"><xs:annotation><xs:documentation>Each DatumDefinition element gives information about a datum.</xs:documentation></xs:annotation></xs:element></xs:sequence><xs:attribute name="n" type="NaturalType" use="required"><xs:annotation><xs:documentation>The required n attribute is the number of datum definitions in the list.</xs:documentation></xs:annotation></xs:attribute></xs:complexType>
<xs:attribute name="n" type="NaturalType" use="required"><xs:annotation><xs:documentation>The required n attribute is the number of datum definitions in the list.</xs:documentation></xs:annotation></xs:attribute>