Compare the rule with concrete cases
Fictional note names an author and a custodian. Both are required, but the model allows the same person in both roles. N1 has Ada/Ada; N2 Ada/Bo; N3 has no custodian. “Two roles” does not mean “two distinct people” unless that extra restriction is stated.
| Note | Author | Custodian | Validity |
|---|---|---|---|
| N1 | Ada | Ada | Valid |
| N2 | Ada | Bo | Valid |
| N3 | Ada | Absent | Invalid |
Work through the distinction
A single contact field cannot show whether both roles were assigned. Conversely, a distinct-person rule would unnecessarily reject N1 under the supplied policy.
The custodian on N1 changes from Ada to Bo. Does its author change too?
Show the worked answer
No. The role links are separate. Author remains Ada unless an independent author change is made.
Acceptance wording to adapt
Store separate required author and custodian references. Allow them to equal the same existing person ID. Updating one role must preserve the other role’s reference.