Source codes are part of the Audit Trail feature in Navision. Source code allow you to track the records in posted tables originated from what journal or order. When you first create a company, a set of default source codes already defined for you.
You can view all the source codes defined at:
FINANCIAL MANAGEMENT --> Setup --> Trail Codes --> Source Codes.
How do Navision know which source code to you when you post a journal or order ? All this is defined in the SOURCE CODE SETUP window. To access the Source Code Setup window, click on FINANCIAL MANAGEMENT -->Setup --> Trail Codes --> Source Code Setup to open up the setup table as shown in the following figure.