Status: implemented

Implemented — this change has shipped.

RFC 0052: Named exit sale deductions

Summary

RFC 0045 gives the disposition slot one transaction_costs category. Every cost of sale — commission, transfer tax, title, legal — collapses into rows that differ only by their author's free-text label, so no consumer can roll up "what did the exit actually cost" across two producers.

This contract adds a closed sale_deductions vocabulary that names each disposition-slot transaction_costs row, and a net-sale-proceeds verifier that checks a stated net figure against gross sale less those named deductions. It adds no new cash rows, no new economics, and no derived exit value.

Motivation

The StackUW protocol brief asks for named exit deductions. Today an engine emitting -412,500 at the disposition date can say only that it is a transaction cost. A reader cannot tell a 2.5% brokerage commission from a municipal transfer tax, cannot compare deduction load across deals, and cannot check a stated net-proceeds figure without re-reading prose.

Naming is also the only honest way to hold the RFC 0045 boundary. The assembly is explicitly unlevered and pre-tax, but the deductions a seller actually pays at closing include prepayment penalties and loan payoffs. Those are below-NOI, levered amounts. While every deduction is anonymous, nothing stops one from entering the unlevered stream and quietly making the candidate wrong.

Proposed change

1. The vocabulary

Add a closed set of deduction names. The first six are ordinary unlevered costs of sale:

Name	Covers
broker_commission	Listing and buy-side brokerage fees.
transfer_tax	Documentary, transfer, stamp and recording taxes.
title_and_escrow	Title insurance, escrow and closing-agent fees.
legal_and_closing	Seller's legal, and closing costs not named above.
seller_credits	Credits and concessions granted to the buyer at closing.
survey_and_diligence	Seller-paid survey, environmental and diligence costs.
other	Anything else. REQUIRES a nonempty author label and provenance.

other is a named escape hatch, not a default. It keeps the first real deal with an unusual deduction from blocking on a spec change, while still forcing the author to say what the amount is. An other row without a label refuses.

2. Reserved levered names

prepayment_penalty, defeasance and loan_payoff are reserved in the vocabulary and refused by this unlevered assembler. Stating one refuses with a message naming the basis conflict and pointing at the levered contract that does not exist yet.

Reserving rather than omitting them does two things: it stops a later levered RFC from colliding with a name an adopter has already used for something else, and it turns a silent basis violation into an explicit, explained refusal. An author who genuinely needs such an amount in a candidate stream must state it as other with a label — which makes the choice visible in the evidence rather than hidden in a generic cost row.

3. Binding names to rows

Add an optional sale_deductions member to PropertyCashFlowPlan:

type SaleDeductionName =
  | 'broker_commission' | 'transfer_tax' | 'title_and_escrow'
  | 'legal_and_closing' | 'seller_credits' | 'survey_and_diligence'
  | 'other'
  | 'prepayment_penalty' | 'defeasance' | 'loan_payoff'; // reserved; refused here

interface SaleDeduction {
  row: number;           // a supplemental row index covering (disposition, transaction_costs)
  name: SaleDeductionName;
  label?: string;        // required when name is 'other'
}

When sale_deductions is present it MUST name every row bound to the (disposition, transaction_costs) cell, exactly once. A partial naming refuses: a rollup over some of the deductions is worse than no rollup, because it looks complete. Naming a row that the cell does not cover refuses. Duplicate rows refuse. Omitting sale_deductions entirely remains valid and preserves today's behavior.

Names carry no sign rule of their own; the existing rule that transaction_costs rows are nonpositive already governs, seller_credits included. Nothing about a name changes an amount, a date or a row's place in the series. Each deduction remains its own dated §4.26 row.

4. Net sale proceeds

Add an optional net_sale_proceeds to the plan: a stated amount the assembler verifies rather than derives.

Verification is sum(gross_sale rows) + sum(transaction_costs rows) at the disposition slot. Both sides quantize at the §VIII.9.4 currency quantum — the existing CASH_FLOW_VERIFY_DECIMALS.currency, two decimals — before comparison, which is the §VIII.5 posture the cash-flow verifier already takes. Deduction rows are nonpositive, so the sum is a subtraction. A mismatch refuses with both figures in the message.

The verifier deliberately spans the whole transaction_costs cell, not only the named rows, so it cannot be satisfied by leaving a deduction unnamed. It does not touch reserve_net: a returned reserve is not sale proceeds, and RFC 0045 already requires gross sale to exclude it.

Stating net_sale_proceeds without a gross_sale row refuses. Omitting it leaves the result's verification status not_stated, exactly as the existing supplemental-metric evidence does.

5. Result evidence

PropertyCashFlowAssembly gains:

sale_deductions?: Array<{
  output_row_index: number;
  name: SaleDeductionName;
  label?: string;
  amount: number;
}>;
net_sale_proceeds: { status: 'verified'; stated: number; computed: number }
                 | { status: 'not_stated' };

sale_deductions is present only when the plan named them. As everywhere else in RFC 0045, this is evidence about stated amounts, not proof that the deductions are complete or that the exit is real.

6. Refusals

Extend the PropertyCashFlowAssemblyIssue reason enum with sale_deduction. It covers partial or duplicate naming, a named row outside the cell, other without a label, a reserved levered name, and a failed net-proceeds check. Existing reasons are unchanged.

Compatibility

Purely additive and opt-in. sale_deductions and net_sale_proceeds are optional; a plan omitting both behaves exactly as it does today, and every existing fixture stays valid. The reason-enum extension widens a union that only appears in refusals. No released behavior changes, so this is a Protocol minor.

Out of scope

Deriving net proceeds from a cap rate or NOI; any levered exit treatment; capital-gains or depreciation-recapture tax; deduction-to-payee mapping; percentage-stated deductions (RFC 0045 already requires stated cash payments, not recomputed percentages); and acquisition-slot cost naming, which deserves its own vocabulary decision rather than a mirrored guess.

Conformance

• A positive case naming six deduction kinds with a verified net-proceeds figure.
• other with a label passes; other without one refuses.
• A partial naming refuses; a duplicate row refuses; an out-of-cell row refuses.
• Each reserved levered name refuses with the basis message.
• A net-proceeds figure off by one minor unit refuses at the currency quantum.
• An existing RFC 0045 fixture with neither member continues to pass unchanged.