Allows to add an optional field to the confirmation e-mail sent to the Merchant. It can be viewed: In the Merchant Back Office in the transaction details section (Extras tab). In the data transmitted to the merchant website when returning to the shop. In the data transmitted to the merchant website during the IPN. By default, in the payment confirmation e-mail sent to the Merchant. In the payment confirmation e-mail sent to the Buyer, if you specify it in the notification.
Required syntax: vads_ext_info_fieldname=valueInput and output field, returned in the response (IPN and Return URL). | 
