You can assign reason codes to individual transactions. You may want to use reason codes only for certain transactions, or you may want to assign a different reason code to a transaction than the code assigned to the journal batch or journal template.
Go to the journal window (for example, the 
General Journal
window).
Enter the code in the Reason
Code field on the journal line. (The field is not included
in the standard layout, but you can insert it with the Show Column
function.) To insert a code, click the Reason Code field, and then click the
AssistButton 
. Select the desired reason code
on the list, and then click OK.
Using the Show Column Function
Assigning Reason Codes to Journal Batches
Assigning Reason Codes to Journal Templates
Using Reason Codes when Invoicing