Source hierarchy
We prefer regulators, standards organizations, government agencies, official technical documentation, peer-reviewed literature, and established textbooks. Secondary references may clarify a method but cannot override its authority. Competitor pages are product evidence only.
Independence of review
The person approving an expected result must not rely only on the same code that generated it. Formula implementation and formula approval are separate review actions, and high-stakes topics add a qualified domain reviewer. When a version is published under site-owner authorization before that independent review exists, the public assurance remains explicitly limited to engineering tests and does not claim reviewer approval.
Examples and content
Reference vectors remain internal formula-verification evidence; they are not published as generic article copy. Each canonical calculator has independently authored educational content for its own calculation intent, with assumptions, limitations, and related tools linked where they help the reader continue the same task. Any numerical walkthrough must be written for that specific method. Aliases are explained naturally on the canonical page rather than expanded into near-duplicate pages.
Corrections
A material formula or source correction creates a new formula version. The affected tool is removed from publication if necessary, all dependent vectors rerun, visible calculator assumptions and any article-specific walkthroughs update, and the approval trail records the change.
What we do not claim
We do not claim universal agreement with every competitor because competitors can use different methods, settings, dates, or rounding. We claim parity only for a named, versioned comparison profile whose captured vectors pass.