The global ExtrudedCrossSectionFeatureDefinition element gives information about an extruded cross section feature that may be used by more than one feature.
The id attribute is the QIF id of the feature, used for referencing.
Source
<xs:element name="ExtrudedCrossSectionFeatureDefinition" type="ExtrudedCrossSectionFeatureDefinitionType" substitutionGroup="FeatureDefinition"><xs:annotation><xs:documentation>The global ExtrudedCrossSectionFeatureDefinition element gives information about an extruded cross section feature that may be used by more than one feature.</xs:documentation></xs:annotation></xs:element>