Projectwise Audit Trail Action Name

I am creating some reports in Access based off the dms_audt table for Projectwise and while it references action code in the table, it doesn't have any obvious link to another table where it actually pulls the "Checked Out" or "Exported" etc... text and it doesn;t seem to follow a logical pattern as to what code relates to what action.  Where does the text for the action name come from and how can I link it to my query so I can show what action the users in the reports are doing?