Where is backend document number number stored

Hi All,

How do we store backend document numbers displayed in Related documents tab of shopping cart or Purchase Order?

I have an issue that I am not getting this updated even after I run BBP_GET_STATUS_2 job.

I created a partial good receipt at backend side and even that is not updated in SRM.

I can see these fields are updated at line item of shopping cart

VAL_CF_E                               150.00

VAL_PO_E                                0.00

QUAN_CF_E                            10.000

QUAN_PO_E                            25.000