Legal
Methodology versioning policy
A score that can be silently changed is not evidence of anything. This policy is what makes our published figures reproducible after the fact.
Immutable releases
A released version and its factor set are never edited. Corrections ship as a new version, never as an in-place amendment.
Semantic increments
A patch corrects an error without materially changing scores. A minor release adds factors or categories. A major release changes the formula itself.
Re-scoring
When a release materially changes scores, the catalogue is re-scored. The previous score record is retained, not replaced.
Deprecation
A superseded version keeps answering API requests for a stated window before retirement, so integrations are never broken without notice.
What ships with every release
Each release publishes its version number, release date, a plain summary and an itemised changelog, all visible on the methodology page rather than held internally.
Every score displayed on this site names the version that produced it. If those two ever disagree, treat it as a bug and tell us.