Status: Proposed, 12 September 2026. Not decided. Awaits the engineering lead and an independent reviewer (blueprint R06).

Context

Two token amounts can sit in a series contract without being owed to anyone: a surplus (someone transferred a component to the contract directly — a "donation" — or a component's balance rose on its own) and dust. Many contracts give an admin a function to take such amounts. The blueprint (§7, §11) proposes none, because a function that can take a surplus is a function that can take backing if the accounting is ever wrong, and a claim that can be paid to an address of someone's choosing is a claim that can be stolen with a key.

Decision

• —No sweep. There is no function that moves a component out of the series except claimComponent, which pays a recorded claim to its holder. Surplus stays in the contract as extra backing. Donations do not create lots, do not raise anyone's claim, and are visible in the reconciliation as SURPLUS, never counted as owed.
• —Claims pay the caller. claimComponent pays msg.sender the whole of msg.sender's recorded claim for that component and nothing else. There is no to parameter and no operator function to pay on a holder's behalf.
• —Effects before transfer, and the transfer is checked. The claim is set to zero and the reserve reduced before the token is called; if the token reverts, returns false, or moves the wrong amount, the whole call reverts and the claim stays whole. A component that takes a fee on transfer therefore cannot be paid from the series (TransferFailed), which is deliberate: a fee would be paid out of other holders' backing.
• —Claims never read the other component. A claim of A does not call B, so a broken or reentrant B cannot hold A.

Consequences

• —A mistaken transfer to the series is not recoverable by the operator. The doctrine of the site says so in the same words it uses for everything else: what was sent is sent.
• —A component that changes to charge a fee on transfer stops paying from the series until the fee is gone. The claim is kept; the holder waits or the series is retired.
• —Reconciliation can show SURPLUS indefinitely. That is a reported fact, not a balance to be "cleaned up".

What exists today

CompanySeries.sol has no sweep or rescue function; claimComponent pays msg.sender, sets effects first, checks the balance delta, and is nonReentrant; MockToken switches (return-false, fee, reentrancy, halted) exercise it in T07, T08, T11, T12, T20, T22–T25 and the fuzz run. The reconciliation reports SURPLUS separately from MATCHED.

Open

• —Whether an explicit, operator-signed retirement of an empty series (zero lots, zero claims) should be able to forward a remaining surplus to a published address, or whether surplus simply stays. The proposal is that it stays: the case is rare and the function is the kind this record refuses.