Yes, we also think the OEM ref is unique in most cases, but we also met the same OEM has several versions of products( the difference might be small or big,depending on market) When we 're not sure our item is exactly matching/crossing the OEM no whatever your inquiry or other clients, we do the same operation (marking yellow). Otherwise, if we knew it was wrong one, are we mad/crazy to continue the delivery?? We like claims??