What do the Amount Fields mean in the Pledge Payments Due Export?

The Pledge Payments Due Export can be used to create reminder letters for Pledges.  The attached document explains what the different Amount fields are in the export.

Tip for selecting the export to get the correct Amount Due: If you are creating Pledge reminder letters for Pledges due in a particular month or other date range, you must make a date range selection using  Date Due from the Pledge Transaction fields.  If no selection is made on this field, the amount in this field will be the total amount due no matter when payment is due.