If you are using L_AMTn and/or L_QTYn in a DoDirectPayment API call, which of the following parameters must also be specified?

While creating a Buy Now button using Merchant Services, which of the following parameters are optional under Item Details?

Which of the following are valid refund types for the REFUNDTYPE parameter of the RefundTransaction request?

While making a DoDirectPayment API call, which of the following Parameters must be included in the Name-Value string?

If the Auto Return feature is enabled in the PayPal profile, which of the following PayPal payments will it apply to?

In which of the following buttons is the PayPal Account Optional feature available?