<xs:group name="UnderlyingInstrumentElements"> <xs:sequence> <xs:element name="UndAID" type="UndSecAltIDGrp_Block_t" minOccurs="0" maxOccurs="unbounded" /> <xs:element name="Stip" type="UnderlyingStipulations_Block_t" minOccurs="0" maxOccurs="unbounded" /> </xs:sequence> </xs:group>