FC6 — UPDATING a field the caller may read but not write is REJECTED over the wire, and the
rejection carries the EXPLICIT write wording rather than the ambiguous read wording
(test-plan 3.9, plus the read/write denial split).
The split is the point: a caller who can SEE the field already knows it exists, so naming the
missing permission discloses nothing they could not learn by attempting the save. Asserting
the ambiguous wording here would pin the wrong contract.
FC6 — UPDATING a field the caller may read but not write is REJECTED over the wire, and the rejection carries the EXPLICIT write wording rather than the ambiguous read wording (test-plan 3.9, plus the read/write denial split).
The split is the point: a caller who can SEE the field already knows it exists, so naming the missing permission discloses nothing they could not learn by attempting the save. Asserting the ambiguous wording here would pin the wrong contract.