Transparent formulas
A calculator should identify its inputs, units, formula, worked example, and practical limitation. Where a result depends on a product yield, carrier divisor, tariff, or user-supplied rate, the assumption is shown rather than hidden.
Data governance
Market-sensitive records use source, effective date, review date, confidence, region, and verification status. Pending records are not recommendations. Expired or low-confidence data should be reviewed before it is used in a decision.
Verification and release
Changes receive a behavior test at the public seam, source review, generated-route checks, and live or production-like browser verification. Optional services have kill switches or safe fallbacks so disabling them does not break core calculations.