Main idea

The natural move, when a rule changes, is to update the document that carried it. Two years after writing "French and English by default, other languages subject to signed revenue", the team that decides to translate secondary languages automatically with human review on critical journeys opens the file and corrects the sentence.

That move destroys exactly what the document was there to preserve. A decision is not a state, it is a pair: a choice and the context that made it reasonable. Rewriting does not merely replace the old choice, it deletes the old context — the translation cost of the time, the quality then achievable, the support tooling then available. What is left is a current rule with no past, indistinguishable from a rule that had always been that one.

The correct form is therefore accumulation: the old decision stays in place, marked as superseded, and points to the one that takes over. The old one explains why the company had refused; the new one explains why that refusal is no longer fit. Neither says the other was wrong.

The same form holds for the description of an object, and for one further reason. When an object in a product is rethought from top to bottom, you do not modify its card: you create a new one, and the old one stays. It does not merely serve to explain what was thought at the time — it remains necessary to interpret the data and exchanges predating the change, which go on existing and being read according to the old model.

Layer added by "I wrote a product's ontology. Three times, I thought I was done." (2026-08-11).

Why it matters

This prevents a common and not very admissible use of decision documents: rewriting them to mask a change of position, which gives the organization the retrospective appearance of having always been right.

It also supplies the material nobody thinks to keep — the succession of contexts — which is the only way of knowing how fast a company's assumptions expire.

Nuances and limits

Accumulation has a reading cost: several decisions stacked on the same subject force you to know which one is in force, which assumes disciplined marking that nothing guarantees.

And not every correction is a replacement: fixing a drafting error or clarifying an ambiguous phrasing does not change the decision and calls for no new document.

Open questions

• After how many successive replacements does a series of decisions on the same subject stop being legible, and what should then be done with it?