If verification is required
<ThreeDSecure>
	<verify>yes</verify>
	<merchant_url>https://www.widgets.com/</merchant_url>
	<purchase_desc>DVD</purchase_desc>
	<purchase_datetime>20150101 21:59:42</purchase_datetime>
	<Browser>…</Browser>
</ThreeDSecure>

If verification is not required
<ThreeDSecure>
	<verify>no</verify>
</ThreeDSecure>