A principle is written as a value, unless it is actually a rule

ADR-065: A principle is written as a value, unless it is actually a rule

Status Active · Filed 2026-08-25

Context

A principle about environment coupling was drafted as “a record must not constrain the project it records” and reviewed as a prohibition wearing a principle’s clothes. Rewritten as “meet the project where it is”, with the same evidence and the same corollary, it read as something to work toward.

The rewrite was not only a matter of tone. The negative form failed a case the positive one handles: a self-hosted forge gets a record that works and one field to fill in by hand. Under must not constrain, that is a violation and has to be argued away. Under meet the project where it is, it is the aspiration partly met, which is what it is.

That is the general shape. A rule has a boundary you are on one side of. A value has a direction you are somewhere along. Stating a value as a prohibition collapses the second into the first, and the state it deletes — partly met, and moving — is where a value spends most of its life.

The corpus had already worked this out without saying so. Of fourteen principles, twelve are positive: an imperative (Fire before trusting, Culture must be compiled, One decision, one thing), or a diagnosis paired with a remedy (A hand-maintained projection of a source of truth will drift — derive it). Two are negative — No silent refusal and No private brains — and both are genuinely rules: there is a line, and crossing it is the failure. The pattern was right and unstated, which is the condition where the next draft goes the other way. One just did.

Decision

Write a principle in the voice of what it is.

The default is aspirational, because most principles are values: state what to move toward, and let the body carry what goes wrong when you do not. A title that reads as a direction is also more usable at the moment of citation — somebody deciding between two designs can ask which one moves toward it, where a prohibition only answers whether either is forbidden.

Use the constraining voice when the principle is a rule. No silent refusal should not become “prefer to explain what was refused”; the whole content is that there is no acceptable case. Softening a real rule into an aspiration is the same error in the other direction, and it is worse, because it makes a hard line look negotiable.

Three shapes, all legitimate, and the record already uses all three:

shape	example
value, as an imperative	Meet the project where it is
observation, with the remedy attached	A hand-maintained projection of a source of truth will drift — derive it
rule, stated as a boundary	No silent refusal

The test when drafting: can this be partly met? If yes, it is a value and wants the aspirational voice. If the only states are satisfied and violated, it is a rule and should say so.

Alternatives considered

• Require the positive voice everywhere. Simpler to state and it would have forced No silent refusal into a softer sentence than the thing it means. A convention that mangles its own best examples is not ready to be a convention.
• Leave it to taste. What was in force until now, and it worked for twelve principles before producing one that had to be rewritten after review. The cost of leaving it unstated is not high — a draft and a rewrite — but the rewrite happened because a reviewer caught it, which is the surface this record elsewhere declines to rely on.
• Lint it. The obvious next rung, and it does not reach. Register is not regex-judgeable: a pattern for must not, never and no fires on both principles where the negative voice is correct, and misses a prohibition phrased positively (“always name the reason” is a rule). A check wrong more often than right gets switched off, which is the same reasoning that keeps narrow-titles a warning over a vocabulary the project supplies.

Consequences

This is a convention that stays a convention, which sits against the habit of walking one up to a mechanism when it matters. The exception is stated rather than left implied: the judgement is about voice, a machine cannot make it, and a bad check here would cost more than the mistake it prevents. What can be done instead is cheap — the question can this be partly met? is in the principle template, where a drafter meets it.

Two existing principles were read against this and left alone. No silent refusal and No private brains are rules and keep their voice. Nothing in the corpus needs rewriting, which is the expected outcome when a decision records what was already being done.