<xs:attributeGroup name="PosUndInstrmtGrpAttributes"> <xs:attribute name="UndSetPx" type="UnderlyingSettlPrice_t" use="optional" /> <xs:attribute name="UndSetPxTyp" type="UnderlyingSettlPriceType_t" use="optional" /> <xs:attribute name="UndlyDlvAmt" type="UnderlyingDeliveryAmount_t" use="optional" /> </xs:attributeGroup>