The Back Order Viewer shows you a live list of the back orders currently on a list. To open this window, go to the General tab of a list's properties, and press View Back Orders...
Columns
For each back order, the table shows the puller, the query, the number of requested entries, the number of required entries, and the number fulfilled so far. If a pull defined an object/node to pull rather than an SQL query, the query column will display the path to the object/node.