Data in BOM_STRUCTURES_B with PK1_VALUE and assembly_item_id as null

Hi experts

When upgrade from 11.5.10 to R12, error out: duplicate BOM data in BOM_STRUCTURES_B , run below script

select * from BOM.BOM_STRUCTURES_B where obj_name is null and pk1_value is null
and pk2_value=84 and ALTERNATE_BOM_DESIGNATOR is null;

ASSEMBLY_ITEM_ID ORGANIZATION_ID COMMON_BILL_SEQUENCE_ID BILL_SEQUENCE_ID
                                                 84                                      45449                                 45449
                                                 84                                       81427                                  81427
                                                 84                                      123593                                  123593
                                                 84                                      126708                                   126708
                                                 84                                      133468                                   133468
                                                 84                                      133972                                     133972
                                                84                                        134499                                    134499
                                                 84                                       135564                                    135564

created_by are populated , user of created_by  only have Inquery BOM responsibility, cannot update/create BOM.

My question: Where these datas came from? Which action can populate data into this table?

From bug 5919292, I know that upgrad will populate data into BOM_STRUCTURES_B .