This article explains how, when using a File Data Source, the Display on Form setting of Display and Allow Changes affects the printed label.
A field having a File Data Source will display on the On Demand Print form the path and file name of the file containing the data for that field. When the label prints, the text contained within the file specified will print in the field. Display and Allow Changes allows the user to select a different text file to be used during the print process. The text from the newly selected file will be used as the data for the field when printed.
In the following example, the text from the FILE1.txt file will be printed in the Text00001 field during printing by default.
The FILE1.txt file contains the following text.
During On Demand Print, the full path and file name are shown in the Text0001 field.
The actual print output will contain the text from the FILE1.txt file.
If the user changes the file name during a print, the text from the new file will be used.