Specify a List of Data Items for an Object
Specify the list of data items for an object
when you must reference a data item that is in a query but is not
in the layout.
For example, you want to add a layout calculation to a list that uses a data item that is in the query definition. If the data item does not appear in the list, you must reference it in order to make the layout calculation work. You must also specify the list of data items if you apply conditional formatting that uses a data item that is not in the query.