You may have certain salary codes for your own use that aren't handled by your payroll system. Using the filter below, you can determine which salary codes should not be included in your CSV payroll export. These codes will still be visible in your PDF payroll report.
Go to Settings > Payroll > Prints and select the tab 'Ignore Salary Codes'.
Click on "Create" and enter the salary code you wish to be ignored.
Click on the check mark on the far right-hand side to save.