ABAP field name 'ITM_NUMBER' is not unique

Hello guys,

       Recently I had been creating a ODATA Service using standard bapi  i.e BAPI_SALESORDER_CREATEFROMDAT2 ..

and currently creating the data model via 'Import via RFC/BOR' ..

since I want to have two fields referencing same 'abap field' i.e 'ITM_NUMBER' in this case... but I am facing error .. it says

ABAP field name 'ITM_NUMBER' is not unique.

I have attached the error snapshot for clear idea..

1. Pic from properties section..

2.Error

a quick reply will be great..

Hearty Thanks for read.

Regards,

Pavan Golesar