The WeldCharacteristicDefinitionBaseType is the abstract base type that specifies welding information that can be common to more than one welding characteristic.
The id attribute is the QIF id of the characteristic, used for referencing.
Source
<xs:complexType name="WeldCharacteristicDefinitionBaseType" abstract="true"><xs:annotation><xs:documentation>The WeldCharacteristicDefinitionBaseType is the abstract base type that specifies welding information that can be common to more than one welding characteristic.</xs:documentation></xs:annotation><xs:complexContent><xs:extension base="CharacteristicDefinitionBaseType"/></xs:complexContent></xs:complexType>