The LineFeatureDefinitionType defines the line feature nominal information that can be common to one or more line features. There is no definition information for a line feature beyond what is provided by the CurveFeatureDefinitionBaseType.
The id attribute is the QIF id of the feature, used for referencing.
Source
<xs:complexType name="LineFeatureDefinitionType"><xs:annotation><xs:documentation>The LineFeatureDefinitionType defines the line feature nominal information that can be common to one or more line features. There is no definition information for a line feature beyond what is provided by the CurveFeatureDefinitionBaseType.</xs:documentation></xs:annotation><xs:complexContent><xs:extension base="CurveFeatureDefinitionBaseType"/></xs:complexContent></xs:complexType>