This section lets you select which write offs to include based on the transaction code of the "Type 4" description only transaction assigned to the write off.  

All Transaction Codes Select this option to include all write offs on the report regardless of the transaction code assigned to the write off.
Select Transaction Codes

Select this option to include write offs with specific transaction codes assigned to their “Type 4” description only transactions. When the Select Transaction Codes option is selected, the Tcode button will be available. Click the this button to open a Tcode Lookup window and select the transaction codes you want to include on the report.

Note: Select the “Not Assigned” option in the Tcode Lookup window to include write offs for which no transactions were created and reversed write offs (if the Reversed Write Offs check box is selected in the Include section).