Compare the rule with concrete cases
The complete fictional state has the three fields below under stable IDs N1,N2. An authorised edit changes N1.body from old to new; N1.title=Alpha and N2.body=other must remain. A correct new body with a changed N2 still fails.
| Field | Before | Expected after | Allowed change |
|---|---|---|---|
| N1.body | old | new | Yes |
| N1.title | Alpha | Alpha | No |
| N2.body | other | other | No |
Work through the distinction
Checking only the target field misses unintended side effects. Define a finite fixture state so the preserved fields can be compared before and after without guessing what else existed.
N1.body is new but N1.title becomes Beta. Is the edit acceptable?
Show the worked answer
No. The title is outside the permitted change set and should still be Alpha.
Acceptance wording to adapt
For this edit change only N1.body to new. Preserve N1.title and every field of N2 exactly. Acceptance requires both the target change and the stated unchanged values.