Is the value of the "Number" field not unique?

Question

1C

UX 3.1.4.9 when creating a Counterparty Agreement, the error "The value of the field "Number" is not unique" appears. In this case, the number is entered manually and still an error.

Answer 1

Well, it means that it is not unique and somewhere in the database there is already an agreement with that number)

Answer 2

enter unique

Answer 3

How do you get these reference books?

Add to the form to display the Number is systemically called the Code, it is being checked. And this is not the props ("Contract number") that you circled)