If you set up any of your User-Defined Fields (UDFs) as a Text Field Type and selected the Lookup/Code check box in the PO Add or Edit User-Defined Fields window, you can select the UDF from Options > Codes on the menu bar. After you select the code, you can define as many instances of it as you need for your business. You can then attach the specified codes to purchase orders if you set up the UDF to show in your layout. For example, if you have a UDF of Approved By, you can create codes that identify the different people in your company that approve purchase orders.