To add an item to the SaveForLater area, use "SaveForLater" as the value for the Action parameter in a CartModify operation, for example:

http://ecs.amazonaws.com/onca/xml?
Service=AWSECommerceService&
AWSAccessKeyId=[AWS Access Key ID]&
AssociateTag=[Associate ID]&
Operation=CartModify&
CartId=[Cart ID]&
HMAC=[HMAC]&
Item.1.CartItemId=[Cart Item ID]&
Item.1.Quantity=1
Item.1.Action=SaveForLater

In this request, the item identified by Item.1 is moved to the cart's SaveForLater area. The Quantity parameter enables you to move only some of one type of item into the SaveForLater area, for example, if you had fifteen copies of the book, Saving Miss Oliver's, in the cart, you could move eight of them to the SaveForLater area by setting Item.1.Quantity=8 in the preceding request.

Notice that only CartModify can move an item between the Active and SaveForLater areas. This means that an item cannot be added directly to the SaveForLater area; it must first be added to the cart using CartCreate or CartAdd and then moved to SaveForLater. Amazon will automatically move an item to the SaveForLater area if the item is currently unavailable. CartModify will not be able to move that item into the Active area until it becomes available. At that time, Amazon will move the item automatically into the Active area.

To move an item from the SaveForLater area to the Active area, use " MoveToCart" as the value for the Action parameter in a CartModify operation:

Item.1.CartItemId=[Cart Item ID]&
Item.1.Quantity=1
Item.1.Action=MoveToCart