The flag word

requestAction returns a flag word and emits it on IntentRecorded before the pass/fail branch. Zero means the action executed. Anything else means it was held, and each bit names the clause it is written down as.

Bit	Flag	Meaning	Clause
0	AGENT	Sender is not the agent this mandate names	—
1	PER_ACTION	Notional above the per-action cap	2.1
2	PAIR	Structural: the pair is enforced by measurement	2.2
3	VENUE	Target is unclassified for this owner	2.3
4	EXPIRY	Mandate expired	2.4
5	REVOKED	Mandate revoked by its owner	—
6	AGGREGATE	Epoch notional would cross the aggregate cap	3.4
7	RATE	Epoch action count would cross the limit	3.5
8	VENUE_CONC	Off-primary share would cross the bound	3.7
9	DEPTH	Structural: delegation depth refused at registration	—
10	RETURN	The agent asked for less back than the mandate requires	2.5

PAIR and DEPTH are never raised. They exist in the word so it is complete: the pair is enforced by measurement — the guard only approves the mandate's tokenIn and only credits its tokenOut — and depth by refusal at registration. TIER1_MASK and TIER2_MASK are read from the contract rather than restated, so a screen and the guard cannot drift.

RETURN is tier 1 — what one action must give back is a property of that action, not of the sequence it belongs to. It is raised before the venue is called, so an agent that asks for a price the owner never accepted is held rather than executed. The same floor is measured again after the venue answers, and that check has no flag: value has already left, so it reverts rather than holding.