Setup table filling

Hi Experts,

In LO extarction for Sales order,Delivery and Billing Numbering used are 11 ,12 and 13 respectively whereas for the same application when we perform setup table filling we use 7,8 and 9 for Order,Delivery and Biling respectively Eg.OLI7BW.Could any one explain what does 11 and 7 contain?

Regards

Kumar