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ES scope

This page defines the I1 conformance boundary. If a feature is outside this boundary, it does not block the language half of 0.0.1 — but it must still be listed honestly if users might expect it.

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Spec pin

When re-pinning:

1. Update Sources (edition snapshot URL + date)
2. Diff the feature matrix for new rows
3. Bump Test262 pin to a matching suite revision
4. Update engineering docs/es-pin.md + docs/matrix/language.md in the scripty repo
5. Open engineering work for deltas — do not claim the new edition until matrices catch up

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In scope (blocks language gate)

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Annex B policy

Document each Annex B decision in the feature matrix.

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Explicitly out of scope for I1

Host-provided job scheduling, timers (setTimeout), and I/O are runtime concerns. I1 requires that when the host enqueues Promise jobs, Promise semantics match the spec. Timer APIs themselves are not ES language features.

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“Fully compatible” checklist

Use this checklist in release review:

• Edition pin matches claimed release notes
• Test262 pin recorded; CI green for in-scope set
• Zero open blockers on in-scope failures
• Feature matrix has no in-scope unsupported or partial rows
• Annex B policy rows reviewed
• No marketing claim of browser or npm completeness

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Relationship to internal matrices

The scripty repo keeps engineering matrices under docs/matrix/language.md. This public matrix is the program-facing source of truth for the ES2026 goal. When they disagree, update both in the same change set.