Iprocurement Punch-in missing some data

As part of Iprocurement Punch-in from the External Punch-out site,  the data sent as XML to Shopping cart page  is missing two data elements but the remaining ones are transmitted. The two data elements missing are part of XML tag

<OrderLinesDataElements>

The XML tag fields are:

<catalogType> xxxxxxx </catalogType>

.....

<attribute5>xxxxx</attribute5>

Can you let me know the reason why the data for the above fields are not transmitted to shopping cart.

Thanks.