Macro-4 Standard IO Contract Output Section — R2-B2 (2026-06-19)

Date: 2026-06-19 · Workstream: R2-B2-MACRO-4-STAGING-WORKBENCH-IO-CONTRACT-TD-ENTRY-GATE-2026-06-19 (Deliverable 22 of 90) · Editorial revision: rev1 Class: IO contract output section · READ-ONLY · NON-ENACTING · NON-AUTHORIZING · NO write performed.

Metadata convention. Editorial revision (rev1) only. Storage revision/content_length authoritative at read time.

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0. Status and non-authorization

STATUS: PASS — engineering / design-only. The output_surface section of the envelope. Engineering PASS ≠ authority PASS. Default: HOLD.

1. Purpose

Define what output_surface means: the exact, narrow set a block writes — and the forbidden outputs.

2. Sources / evidence read

Inspect-producer §7 (B2 output contract); Điều 0-G §2.4 ("mỗi DOT chỉ UPDATE cột của mình"); pilot-slice staging IO contract §5/§6. Main process, no reader-agents.

3. Accepted baseline (carried)

A block writes only its declared output surface; for B2 that is inspect_pen/stamp/gate only, genuine per-stage, one column per inspector, in PEN→STAMP→GATE order, idempotently.

4. Evidence / analysis — output section shape

Element	Requirement
Declared writes	the exact columns/objects the block sets (narrow as possible)
Genuine	each write earned by a real check, never a blanket default
Own-column-only	a block writes only its own surface; no cross-block write
Forbidden outputs	listed explicitly (forbidden_surfaces); see Deliverable 35 for B2
Idempotent	only an unset target is set; no overwrite/re-stamp

5. Contract / requirement / matrix / result

The output section is the block's only write footprint and the only surface other blocks may name as their input. It must not widen silently (a "complete" signal on a partial set is forbidden) and must not add net-new columns (Assembly First).

6. Owner-gated future work

Binding an output surface to runtime writes is Owner-gated; forbidden now.

7. What remains unresolved

The concrete write targets are FUTURE_TECHNICAL_DESIGN_REQUIRED.

8. Ready for GPT/Codex review

Yes — Codex should confirm the output section is narrow, own-column-only, and never widens to certify/canonical.