Here you select the general Storage Overhead mark-up in percent that will apply to the pre-calculation. The standard value for this mark-up is entered under the Calculations heading that you will find under the Manufacturing tab in the Settings procedure.
For purchased parts you can also register SO mark-up exceptions, for example for a purchased part that is included in the calculation, but which is particularly expensive and should therefore have a lower SO mark-up. To be able to use SO Exceptions the setting Use SO/SC mark-up exceptions in the system? must be configured in the same location as above in the Settings procedure. If there are SO Exceptions saved for the part in question, that mark-up is applied as the standard SO mark-up for that part in the calculation. You register SO Mark-up exceptions in the procedure called SO/SC Mark-up Exceptions in the Global Settings module.