Every claim has one home

The rule. Each fact, rule, behaviour and list the record holds is written in exactly one place. Every other place that needs it names that place and stops, rather than saying it again in its own words.

Why. A restated claim is a second claim. Nothing ties the two copies together, so the first edit to either one leaves them disagreeing, and a reader has no way to tell which one the code, the gates or an agent follows. The consistency pass of 2026-10-26 (.abcd/work/reviews/2026-10-26-consistency/) read the brief and every current intent against each other and filed 1,301 records from 1,307 findings. 1,080 of those findings set a passage of the brief against another passage of the brief or against an intent, and 800 of the whole were premise contradictions: two places that state the same premise and disagree on it. A pointer cannot disagree with its home the same way. A markdown link whose target is gone fails the record and docs lints' link check; a bare path in a rules domain is checked by nothing yet, so a renamed home leaves it pointing at nothing, silently.

Bounds.

• A pointer may say in one line what it points to, enough for a reader to decide whether to follow it: an invariant written as one line naming its rule and the ADR that holds it, or a short form in AGENTS.md that names the rules domain carrying the whole rule. It holds nothing the home does not, and it is not where the claim is changed.
• A generated copy is not a second home. A file built from its source by one writer, with a check that the two still match (the CLI reference, a command chapter's generated appendix, the SHELL domain built from the hazard registry), has its home in that source.
• History is not a copy. A superseded design is deleted from the brief, not kept beside the design that replaced it; git and the ADRs keep what it said and why it changed. A dated record (an ADR, a decision, a shipped intent) says what was settled on its date, and a later record that changes it supersedes it rather than standing beside it as a second current answer.
• Terms have one home too: the glossary. A chapter uses a term and links it, never defines it again.
• The rule covers the whole written record: the brief, the intents, the ADRs and decisions, the command pages, the principles, the rules domains, the conventions file and docs/. Code is out of scope: a primitive in code has one home under one canonical primitive.

Promotion. The rule is unenforced. abcd intent consistency finds two places that disagree only after they have drifted, and nothing flags a restatement as it is written, nor a bare path in a rules domain whose target is gone. A lint that did either would promote this principle to a discipline.

Where it was ruled. The product thinker made it a standing rule on 2026-10-27 (dcn-2610271112331508), in settling how the brief's restated sections are cut back.