<swaption>
...
<europeanExercise id="europeanExercise0"> </europeanExercise>
...
<cashSettlement id="cashSettlement0">
...
<cashSettlementPaymentDate>
<relativeDate>
...
<dateRelativeTo href="europeanExercise0"/>
</relativeDate>
</cashSettlementPaymentDate>
</cashSettlement>
</swaption>