Hi Lina,
Just following up on what Ben has said, there is an article about Key field that can be found on BP Docs:
LINK.
If you scroll down to the Key field section of that article it also shows how once you allocate a field as the Key field, it can then be used within a Blue Prism work queue to identify the submission to an item within the queue.
Even though the article was written for Interact 4.2, it works in 4.1 as well.
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Adrian White
Head of Product Consultancy
Blue Prism Ltd
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Adrian White
Head of Product Consultancy
SS&C Blue Prism